# Methods of Analy s is by t he U.S. Geological Survey National W a ter Quality Laboratory

— Determination of Elements in W hole-W a ter Digests Using Inductively Coupled Plasma–Optical Em ission Spectrometry and Inductively Coupled Plasma–Mass Spectrometry

Open-File Report 98–165



# U.S. DEPA RTMENT OF THE INTERIOR U.S. G E O L O G I CA L SURVEY

## ERRATA FOR OFR 98-165

Methods of A n aly s is by the U

. S. G e ological Survey N a tional W a ter Q u ality L a boratory

— D e term ination of E l em ents in W hole-W a ter D i gests U s ing Inductively Coupled Plasm a –O ptical E m ission Spectro m e try and Inductively Coupled Plasm a

– Mass Spectrom e try

The following method number was added on J u ly 17, 2003, to pag e 3 of the Analy tical Methods section of the report:

Inorganic Constituents and Parameter Code: M e t a ls, A c id D i gest ion, Whole- Wat e r R ecov e rable, I- 4472- 97 Inductiv e ly coupled plasma–mass spectrometry

# Methods of Analy s is by the U. S. Geological Survey National W a ter Quality Laboratory

— Determination of Elements in W hole-W a ter Digests Using Inductively Coupled Plasma–Optical Em ission Spectrometry and Inductively Coupled Plasma–Mass Spectrometry

By John R. Garbarino and Tedmund M. Struzeski

_______________________________________________________

U.S. GEOLOGICAL SURVEY

Open-File Report 98–165

D env er , C o l o r ado 1998

## U. S. Depar t ment of the I n ter i or Gale A

. Norton, Secretary

U. S. Geol ogi cal Sur v ey Charles G. Gr oat, Di r ector

T he us e of tr ade, pr oduc t, or f i r m nam es in this r epor t is f o r des c r iptive pur pos es only and does not im ply endor s e m ent by the U.S. G o ver n m ent.

F o r additional inf o r m ation w r ite to: Copies of this r epor t c an be pur c has ed f r om :

Chief

, National W a ter Q uality Labor ator y U.S. G eologic a l Sur v ey U.S. G eologic a l Sur v ey Br anc h of Inf o r m ation Ser v ic es Box 25046, Mail Stop 407 Box 25286 F eder al Center F eder al Center Denver , CO 80225- 0046 Denver , CO 80225- 0286

## CONTENTS

Abstract ......................................................................................................................

...... 1 I n troduction ..................................................................................................................

.......... 1 Analy tical methods

............................................................................................................. .... 3 I nductively coupled plasma–optical emission spectrometry

............................................. 3 1A. Application

......................................................................................................... 3 2A. Summary of method

........................................................................................... 3 3A. I n terfere nces

....................................................................................................... 4 4A. Apparatus, instrumentati on, and operating conditions....................................... 6 5A. Reag ents and calib ration standards

.................................................................... 9 6A. Analy tical procedure

.......................................................................................... 10 7A. Calculations........................................................................................................ 12 8A. Reporting of results

............................................................................................ 12 I nductively coupled plasma –mass spectrometry

............................................................... 13 1B

. Application

......................................................................................................... 13 2B

. Summary of method

........................................................................................... 13 3B

. I n terfe rences

....................................................................................................... 13 4B

. Apparatus, instrumenta tion, and operating conditions....................................... 17 5B

. Reag ents and calibration standards

.................................................................... 19 6B

. Analy tical procedure

.......................................................................................... 21 7B

. Calculations........................................................................................................ 22 8B

. Reporting of results

............................................................................................ 22 Discussion of results

.......................................................................................................... ..... 23 Accuracy and variability

................................................................................................... 23 Results for dig e sted standard reference wate r samples

............................................... 23 Spike recoveries in natu ral whole-water dig e sts

......................................................... 25 Comparison of inductively coupl ed plasma–optical emission spectrometry and inductively coupl ed plasma–mass spectrometry to former methods in the analy s is of natural whole-wa ter dig e sts

..................... 26 Aluminum

................................................................................................................... 28 Antimony

.................................................................................................................... 28 B a rium

......................................................................................................................... 28 B e ry llium

.................................................................................................................... 2 9 B o ron

.......................................................................................................................... . 29 Cadmium

..................................................................................................................... 29 Calcium

....................................................................................................................... 29 Chromium

................................................................................................................... 30 Cobalt

......................................................................................................................... . 30 Copper

......................................................................................................................... 30 I r on ..........................................................................................................................

.. 30 L ead ..........................................................................................................................

.. 31 L ithium

........................................................................................................................ 31 Mag n esium

.................................................................................................................. 31 Mang anese

.................................................................................................................. 31

CO NTENTS III

### CONTENTS—Continued Moly bdenum

............................................................................................................... 32 Nickel

......................................................................................................................... . 32 Selenium

..................................................................................................................... 3 2 Silver

......................................................................................................................... .. 32 Sodium

........................................................................................................................ 32 Strontium

.................................................................................................................... 3 3 Z i nc ..........................................................................................................................

.. 33 Conclusions ...................................................................................................................

......... 33 Summary of test results for inductiv ely coupled plasma–optical emission
spe c t r o me tr y (IC P

– OES )



### ............................................................................................... 33 Summary of test results for inductiv ely coupled plasma–mass spectrometry (IC P

– MS )



### .... 34 References cited

............................................................................................................... ....... 36 Appendix

— I llustrations and tables

......................................................................................... 37

FIGU R ES

1. Schematics showing : 1a. Sample introduction ma nifold for inductively c oupled plasma–optical emission spectrometric method

............................................................................. 39 1b. Sample introduction manifold for inductively coupled plasma–mass spectrometric method

............................................................................................ 39

2–30. Graphs showing : 2a. Sulfate interference on copper dete rminations by inductively coupled plasma–mass spectrometry

................................................................................... 40 2b. Sulfate interference on z i nc de terminations by inductively coupled plasma–mass spectrometry

...................................................................... 40 3. Accuracy of inductively coupled plasma–mass spectrometric sulf a t e de te r mina tions using 32 

### S 16 

### O + 

### response

..................................................... 41 4a. Accuracy of sulfate interference co rrections on copper de terminations by inductively coupled plasma –mass spectrometry

................................................... 41 4b. Accuracy of sulfate interference co rrections on z i nc de terminations by inductively coupled plasma –mass spectrometry

................................................... 42 5a. Short-term inductively coupled pl asma–optical emissi on spectrometric ( I CP–OES) r e sults in r e la tion to the most probable value (MPV) for Standard Reference W a ter Sample T107

........................................................ 43 5b. L ong -term inductively coupled plas ma–mass spectrometric (I CP–MS)

r e sults in r e la tion to the most pr obable value (MPV) for Standard Reference W a ter Sa mple T107

............................................................................. 46

CONTENTS IV

### FIGURES—Continued

6a. Short-term inductively coupled pl asma–optical emissi on spectrometric ( I CP–OES) r e sults in r e la tion to th e most probable value (MPV) for Standard Reference W a ter Sample T119

.............................................................. 48 6b. L ong -term inductively coupled plasma–mass spectrometric ( I CP–MS) r e sults in r e la tion to the most probable value (MPV) for Standard Reference W a ter Sample T119

........................................................ 51 7a. Short-term inductively coupled pl asma–optical emissi on spectrometric ( I CP–OES) r e sults in r e la tion to the most probable value (MPV) for Standard Reference W a ter Sample T133

........................................................ 53 7b. L ong -term inductively coupled plasma–mass spectrometric ( I CP–MS) r e sults in r e la tion to the most probable value (MPV) for Standard Referen ce W a ter Sample T133

............................................ 56 8. Short-term inductively coupled plas ma–optical emission spectrometric ( I CP–OES) r e sults in r e la tion to the most probable value (MPV) for Standard Reference W a ter Sample T135

........................................................ 58 9. L ong -term inductively coupled plas ma–optical emission spectrometric (I CP–OES) and inductively coupled plasma–mass spectrometric ( I CP–MS) r e sults in r e la tion to th e most probable value (MPV) for Standard Reference W a ter Sample W W

- 1............................................................ 61 10a. Scatterg rams and reg r essi on anal y s es showi n g aluminum whole-water dig e st data from inductively c oupled plasma–optical emission spectrometry (I CP–OES) and induc tively coupled plasma–mass
spe c t r o me tr y

( I CP–MS) in r e la tion to t h e form er di rect current pl asm a – atomic emission spectrometr ic (DCP–AES) method

............................................ 65 10b. B o x plots and Kruskal-W a llis Te st results showing aluminum dat a from t h e form er di rect cu rrent plasma–atomic emission spectrometric (DCP–AES) method (g roup 3), inductively coupled plasma–optical emission spectrome try (I CP–OES, g r oup 1), and inductively coupled plasma–mass sp ectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

......................................................................................... 65 11. Scatterg ram, box plots, Paired t -Test resul t s , and reg r essi on coeffi ci ent s showi n g ant i m ony dat a from t h e form er g r aphi t e furnace–at om i c absorption spectrophotom etric (GF

–AAS) method and inductively coupled plasma–mass spectrometry (I CP –MS) for whole-water dig e sts

.............. 66 12a. Scatterg rams and reg r ession anal y s es showing barium whole-water dig e st data from inductively c oupled plasma–optical emission spectrometry (I CP–OES) and induc tively coupled plasma–mass
spe c t r o me tr y

( I CP–MS) in r e la tion to the f o r

m e r f

l a m e

– a t omic absorption spectrophotometri c (F –AAS) method

................................................. 66 12b. B o x plots and Kruskal-W a llis Test results showing barium data from the former flame–atomic absorp tion spectrophotomet ric (F –AAS) method (g roup 3), inductively coupl ed plasma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively coupled plasma– mass spectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

.......................... 67

CONTENTS V

### FIGURES—Continued

12c. Scatterg ram, box plots, One-sa mple Sig n Test, and reg r ession coefficients showing barium data from inductively coupled plasma– optical emission spectrometry (I CP –OES) and inductively coupled plasma–mass spectrometry (I CP–MS) for whole-water dig e sts

........................... 67 13. Scatterg ram, box plots, Paired t -Test resul t s , and reg r essi on coeffi ci ent s showing bery llium data from induc tively coupled plasma–optical emission spectrometry (I CP–OES) and inductively coupled plasma– mass spectrometry (I CP–MS) fo r whole-water dig e sts

......................................... 68 14a. Scatterg rams and reg r ession an aly s es showing boron whole-water dig e st data from inductively c oupled plasma–optical emission spectrometry (I CP–OES) and induc tively coupled plasma–mass
spe c t r o me tr y

( I CP–MS) in r e la tion to t h e form er di rect current pl asm a – atomic emission spectrometr ic (DCP–AES) method

............................................ 68 14b. B o x plots and Kruskal-W a llis Test results showing boron data from
t h e form er di rect current pl asm a –a tomic e mission spe c tr ome t r i c (DCP–AES) method (g roup 3), induc tively coupled plasma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively coupled plasma–mass spectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

............. 69 14c. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coefficients showing boron data from t h e form er di rect current plasma– atomic emission spectrometric (D CP–AES) method and inductively coupled plasma–optical emission sp ectrometry (I CP–OES) for wholewater dig e sts

.......................................................................................................... 69 14d. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coefficients showing boron data from t h e form er di rect current plasma– atomic emission spectrometric (D CP–AES) method and inductively coupled plasma–mass spectrometry (I CP –MS) for whole-water dig e sts

.............. 70 15. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession

c o e f f i c i e n ts showing c a d mium da ta f

r o m the f o r

m e r g r a phite f u r n a c e

– atomic absorption spectrophotom etric (GF

–AAS) method and inductively coupled plasma–mass sp ectrometry (I CP–MS) for wholewater dig e sts

.......................................................................................................... 70 16. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coeffi ci ent s showi n g cal ci um dat a from t h e form er fl am e–at om i c absorption spectrophotom etric (F –AAS) met hod and inductively coupled plasma–optical emission sp ectrometry (I CP–OES) for wholewater dig e sts

.......................................................................................................... 71 17a. Scatterg rams and reg r ession anal y s e s showing c h r o mium whole

- wa te r dig e st data from inductively c oupled plasma–optical emission spectrometry (I CP–OES) and induc tively coupled plasma–mass spect rom e t r y

(I C P –MS ) i n rel a t i on t o t h e form er g r aphi t e furnace– atomic absorption spectrophotom etric (GF

– AAS) method

.................................. 71

CONTENTS VI

### FIGURES—Continued

17b. B o x plots and Kruskal-W a llis Test results showing chromium data from the former g r aphite furnace–at omic absorption spectrophotometric (GF

–AAS) method (g roup 3), inductiv ely coupled plasma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively coupled plasma–mass spectrometry (I CP–M S, g r oup 2) for whole-water dig e sts

................................................................................................................... 72 17c. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession

c o e f f i c i e n ts showing c h r o mium da ta f

r o m the f o r

m e r g r a phite f u r n a c e

– atomic absorption spectrophotom etric (GF

– AAS) method and inductively coupled plasma–optical emission spectrometry (I CP–OES) for whole-water dig e sts

......................................................................................... 72 17d. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession

c o e f f i c i e n ts showing c h r o mium da ta f

r o m the f o r

m e r g r a phite f u r n a c e

– atomic absorption spectrophotom etric (GF

–AAS) method and inductively coupled plasma–mass sp ectrometry (I CP–MS) for wholewater dig e sts

.......................................................................................................... 73 18a. Scatterg rams and reg r ession analy s es showing cobalt whole-water dig e st data from inductively coupled plas ma–optical emission spectrometry (I CP–OES) and inductively coupled plasma–mass spectrometry ( I CP–MS) in r e la tion to the f o r

m e r g r a phite f u r n a c e –a tomic absorption spectrophotometri c (GF

– AAS) method

.............................................. 73 18b. B o x plots and Kruskal-W a llis Test results showing cobalt data from the former g r aphite furnace–ato mic absorption spectrophotometric (GF

– AAS) method (g roup 3), inductiv ely coupled plasma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively coupled plasma–mass spectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

............. 74 18c. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession

c o e f f i c i e n ts showing c oba lt da ta f

r o m the f o r

m e r g r a phite f u r n a c e – atomic absorption spectrophotom etric (GF

–AAS) method and inductively coupled plasma–mass sp ectrometry (I CP–MS) for wholewater dig e sts

.......................................................................................................... 74 19a. Scatterg rams and reg r ession anal y s es showing copper whole-water dig e st data from inductively c oupled plasma–optical emission spectrometry (I CP–OES) and induc tively coupled plasma–mass spect rom e t r y

(I C P –MS ) i n rel a t i on t o t h e form er g r aphi t e furnace– atomic absorption spectrophotom etric (GF

– AAS) method

.................................. 75 19b. B o x plots and Kruskal-W a llis Test results showing copper data from the former g r aphite furnace–ato mic absorption spectrophotometric (GF

– AAS) method (g roup 3), inductiv ely coupled plasma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively coupled plasma–mass spectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

............. 75

CONTENTS VII

### FIGURES—Continued

19c. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coefficients showing copper data from the former g r aphite furnace– atomic absorption spectrophotom etric (GF

– AAS) method and inductively coupled plasma–mass sp ectrometry (I CP–MS) for wholewater dig e sts

.......................................................................................................... 76 20. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coeffi ci ent s showi n g i r on dat a from t h e form er fl am e–at om i c absorption spectrophotom etric (F –AAS) met hod and inductively coupled plasma–optical emission spectrometry (I CP–OES) for whole-water dig e sts............................................................................................... 76 21. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coeffi ci ent s showi n g l ead dat a from t h e form er g r aphi t e furnace–at om i c absorption spectrophotom etric (GF

–AAS) method and inductively coupled plasma–mass spectrometry (I CP –MS) for whole-water dig e sts

.............. 77 22a

. Sc a tte r g r a ms a nd r e g r e ssion a n a l y s e s showing lithium whole

- wa te r dig e st data from inductively c oupled plasma–optical emission spectrometry (I CP–OES) and induc tively coupled plasma–mass
spe c t r o me tr y

( I CP–MS) in r e la tion to the f o r

m e r f

l a m e

– a t omic absorption spectrophotometri c (F –AAS) method

................................................. 77 22b. B o x plots and Kruskal-W a llis Test results showing lithium data from the former flame–atomic absorp tion spectrophotomet ric (F –AAS) method (g roup 3), inductively coupl ed plasma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively coupled plasma– mass spectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

.......................... 78 23. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coeffi ci ent s showi n g m a g n esi u m dat a from t h e form er fl am e–at om i c absorption spectrophotom etric (F –AAS) met hod and inductively coupled plasma–optical emission sp ectrometry (I CP–OES) for wholewater dig e sts

.......................................................................................................... 78 24a. Scatterg rams and reg r ession an al y s es showi n g m a ng anese whol ewater dig e st data from inductively coupled plasma–optical emission spectrometry (I CP–OES) and induc tively coupled plasma–mass
spe c t r o me tr y

( I CP–MS) in r e la tion to the f o r

m e r f

l a m e

– a t omic absorption spectrophotometri c (F –AAS) method

................................................. 79 24b. B o x plots and Kruskal-W a llis Test results showing mang anese data from the former flame–atomic abso rption spectrophotom etric (F –AAS) method (g roup 3), inductively coupl ed plasma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively coupled plasma– mass spectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

.......................... 79 25. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coefficients showing moly bdenum da ta f

r o m the f o r

m e r g r a phite furnace–atomic absorption spectr ophotometric (GF–AAS ) method and inductively coupled plasma–mass sp ectrometry (I CP–MS) for wholewater dig e sts

.......................................................................................................... 80

CO NTENTS VIII

### FIGURES—Continued

26. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coeffi ci ent s showi n g ni ckel dat a from t h e form er g r aphi t e furnace– atomic absorption spectrophotom etric (GF

– AAS) method and inductively coupled plasma–mass sp ectrometry (I CP–MS) for wholewater dig e sts

.......................................................................................................... 80 27. Scatterg ram, box plots, Paired t -Test resul t s , and reg r essi on coeffi ci ent s showi n g sel e ni um dat a from t h e form er g r aphi t e furnace–at om i c absorption spectrophotom etric (GF

–AAS) method and inductively coupled plasma–mass spectrometry (I CP –MS) for whole-water dig e sts

.............. 81 28. Scatterg ram, box plots, One-sa mple Sig n Test results, and
reg r ession coefficients showing sodi um dat a from t h e form er fl am e– atomic absorption spectrophotom etric (F –AAS) method and inductively coupled plasma–optical emission spectrometry (I CP–OES) for whole-water dig e sts

......................................................................................... 81 29a. Scatterg rams and reg r ession analy s es showing strontium whole-water dig e st data from inductively c oupled plasma–optical emission spectrometry (I CP–OES) and induc tively coupled plasma–mass
spe c t r o me tr y

( I CP–MS) in r e la tion to the f o r

m e r f

l a m e

– a t omic absorption spectrophotometri c (F –AAS) method

................................................. 82 29b. B o x plots and Kruskal-W a llis Test re sults showing strontium data from the former flame–atomic absorp tion spectrophotomet ric (F –AAS) method (g roup 3), inductively coupl ed plasma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively coupled plasma– mass spectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

.......................... 82 30a. Scatterg rams and reg r ession analy s es showing z i nc whole-water dig e st data from inductively coupled plas ma–optical emission spectrometry (I CP–OES) and inductively coupled plasma–mass spectrometry ( I CP–MS) in r e la tion to the f o r

m e r f

l a m e

– a t omic a b sor p tion spectrophotometric (F –AAS) method

................................................................... 83 30b. B o x plots and Kruskal-W a llis Test re sults showing z i nc data from the former flame–atomic absorption spectrophotometric (F –AAS) method (g roup 3), inductively coupled plas ma–optical emission spectrometry (I CP–OES, g r oup 1), and inductively c oupled plasma–mass spectrometry (I CP–MS, g r oup 2) for whole-water dig e sts

......................................................... 83 30c. Scatterg ram, box plots, One-sample Sig n Test results, and reg r ession coeffi ci ent s showi n g z i nc dat a from t h e form er fl am e–at om i c absorption spectrophotom etric (F –AAS) met hod and inductively coupled plasma–mass spectrometry (I CP –MS) for whole-water dig e sts

.............. 84

CONTENTS IX

### TA B L ES

1. F o rmer methods, I C P–OES, and I C P–MS method dete ction limits and calibration limits for elements determined in whole-water dig e sts

...................... 4 2. S p ect ral i n t e rferences t h at affect el em ent s det e rm i n ed by I C P

– OES in natural whole-water dig e sts

.............................................................................. 6 3. Analy tical waveleng ths and back g r ound correction points used for the determination of elements in whol e-water dig e sts by I C P–OES

.................... 7 4. Uppe r a nd lowe r c onc e n tr a tion limit a nd c onc e n tr a tion ove r l a p r e g i on for I C P–OES elements having dua l emission waveleng ths

.................................. 8 5. Mole c u la r ion inte r f e r e nc e s f o r

e l e m e n ts de te r mine d in whole

- wa te r dig e sts by I C P–MS

................................................................................................ 16 6. Doubly charg e d ion interferences fo r elements determined in wholewater dig e sts by I C P–MS

...................................................................................... 17 7. I s otopes used to quantify elemen ts de te r mine d in whole

- wa te r dig e sts by I C P–MS

................................................................................................ 18 8. Statistical analy s is of short-term I C P–OES results for U.S. Geolog ical Survey ’s Standard Referen ce W a ter Sample T107

............................................... 85 9. Statistical analy s is of short-term I C P–OES results for U.S. Geolog ical Survey ’s Standard Referen ce W a ter Sample T119

............................................... 86 10. Statistical analy s is of short-term I C P–OES results for U.S. Geolog ical Survey ’s Standard Referen ce W a ter Sample T133

............................................... 87 11. Statistical analy s is of short-term I C P–OES results for U.S. Geolog ical Survey ’s Standard Referen ce W a ter Sample T135

............................................... 88 12. Statistical analy s is of long -term I C P–MS results for U.S. Geolog ical Survey ’s Standard Referen ce W a ter Sample T107

............................................... 89 13. Statistical analy s is of long -term I C P–MS results for U.S. Geolog ical Survey ’s Standard Referen ce W a ter Sample T119

............................................... 90 14. Statistical analy s is of long -term I C P–MS results for U.S. Geolog ical Survey ’s Standard Referen ce W a ter Sample T133

............................................... 91 15. Statistical analy s is of long -term I C P–OES and I C P–MS results for U.S. Geolog ical Survey ’s Standard Reference W a ter Sample W W

- 1

.................. 92 16. Analy tical variability of I C P–OES and I C P–MS results for Standard Reference W a ter Sa mple W W

- 1

........................................................................... 94 17. Analy tical variability of I C P–OE S and I C P–MS over an ex tended concentration rang e

............................................................................................... 95 18. Spike recovery results fo r whole-water dig e sts........................................................... 97 19. Chemical characteristics of na tural whole-wate r samples

.......................................... 100 20. Statistical analy s is summary of I C P–OES and I C P–MS results for natural whole-water dig e sts

.................................................................................. 101

CONTENTS X

### C O N VER SION FA C T OR S, A B B R EVIA T ED WA TER- QUA L ITY UNITS, A DDITIONA L A BBRE V I A T IONS
, A ND DE FINITIONS

Multiply B y T o o b t a i n

lite r ( L ) 2.64 X 10 -1 

### g a llon

m e t e r (m ) 3.94 X 10 1 

### inc h

m i c rog r am (μ g ) 3.53 X 10 -8 

### ounce, avoirdupois milliba r 1.93 X 10 -2 

### pounds per square inch millig r a m ( m g ) 3.53 X 10 -5 

### ounce, avoirdupois millilite r ( m L ) 2.64 X 10 -4 

### g a llon millime te r ( mm) 3.94 X 10 -2 

### inc h nanometer (nm) 3.94 X 10 -8 

### inc h

De g r e e Ce lsius ( o 

### C) may be converted to deg r ee F a hrenheit ( o 

### F ) by using the following equation:

o 

### F = 9/5 ( o 

### C) + 32

A bbr e v iat e d wat e r - qualit y unit s use d in t h is r e p or t :
L /min lite r pe r minute mL /min millilite r s pe r minute
mg /L millig r a m pe r lite r mg /mL millig r a m pe r millilite r μg /L mic r o g r a m pe r lite r μL mic r o lite r μS/c m mic r o sie m e n s pe r c e n time te r a t 25 o 

### C

O t h er ab b revi a ti on s u s ed i n th i s rep ort:

a m u a t omic ma ss unit AS TM Am eri can S o ci et y for Test i n g and Mat e ri al s C A S C h em i cal Abst ract S e rvi c e DCP–AES direct current plasma –a tomic e mission spe c t r o me tr y F

– AAS flame–atomic abso rption spectrophotometry F E P fluorinated ethy lene propy lene (Teflon) GF–AAS g r aphite furnace–atomic absorption spectrophotometry I C P–MS inductively coupled plasma–mass spectrometry I C P–OES inductively coupled plasma–optical emission spectrometry
, also known as inductively coupled plasma–atomic emission spectrometry (I CP–AES) kW kilowa tt lb/in 2 

### pound per square inch

CONTENTS XI

### MDL ( s) method de tection limit(s) M H z me g a h e r t z MPV(s) most probable value(s) NI ST National I n stitute of Standards and Technolog y NWQL Na tiona l Wa te r Qua lity L a bor a t or y QA/QC qua lity a ssur a nc e / qua lity c ontr o l S R W S (s) U.S

. Geol og i cal S u rvey S t andard R e ference W a t e r S a m p l e (s) SOP standard ope rating procedure W wa tt ~ approx imate > g r eat er t h an
< le ss tha n  plus or minus

G l ossary

MDL The method detection limit (MDL ) is defined as the minimum concentration of an el em ent t h at can be m easured and reported with 99- percent confi d ence t h at t h e el em ent a l concent r at i on i s g r eat er t h an z e ro and i s det e rm i n ed from

a n a l y s is of a

sa mple in a g i ve n ma tr ix containing the element of interest (U.S. Environmental Protection Ag ency , 1994).

MPV The most probable value (MPV) is equal to the mean value for numerous interlaboratory analy s es usin g multiple analy tical methods.

Spectrum shifter step One step equals about 0.008 nm.

CONTENTS XII

# Methods of Analysis by t he U.S. Geological Survey National Water Quality Laboratory—Determination of Elements in Whole-Water Digests Using Inductively Coupled Plasma–Optical Emission Spectrometry and Inductively Coupled Plasma–Mass Spectrometry

By John R

. Gar bar i no and T edmund M

. Str u z e ski

A B S T RA CT

I nductively coupled plasma–optical emission spectrometry (I CP–OES) and inductively coupled plasma–mass spectrometry (I CP–MS) can be used to determine 26 elements in whole-water dig e sts. B o th methods have distinct advantag es and disadvantag es—I CP–OES is c a p a b le of a n a l y z ing sa mple s with hig h e relemental concentrations without dilution, howe v e r , I C P–MS is mor e se nsitive a nd c a p a b le of de te r mining muc h lowe r e l e m e n ta l c onc e n tr a

t i ons. Bot h t echni ques g a ve accurat e resul t s for spike recoveries, dig e st ed st andard referencewa te r sa mple s, a nd w hole-water dig e sts. Averag e spi k e recoveri es i n whol e-wat e r di g e st s were 100  10 percent, althoug h recoveries for dig e sts with hig h dissolved-solid concentrations were l o wer for sel ect ed el em ent s by I C P

– MS

. R e sul t s for st andard reference-wat e r sam p l e s

we r e g e ne r a lly within 1 st andard deviation of the most probable values. Statistical analy s is of the results from 43 whole-water dig e sts indicated
t h at t h ere was no si g n i f i cant di fference am ong I C P–OES, I C P–MS, and former official methods of analy s is for 24 of the 26 elements evaluated. INTRODUCTION

Elements associated with water-suspended part i c ul at e m a t e ri al are an important fraction of the tota l e l e m e n ta l c o mposition of na tur a l wa te r

. El em ent s adsorbed t o t h e surface of t h e pa r tic ula t e ma te r i a l a r e solubilize d by using a

m i n eral aci d m e di um at l o w t e m p erat ure and filtered to produce the whole-water dig e st (Hoffman and others, 1996). The U.S. Ge olog ic a l Sur v e y ’ s Na tiona l Wa te r Qua lity L a boratory (NW Q L ) offers several methods for the de te r mina tion of e l e m e n ts in whole

- wa te r dig e sts. F o rmer met hods use sing le-element
qua ntif ic a tion tha t is based on either atomicabsorption or atomic emission spectrophotometry

. Alternative methods by use of inductively coupled plasma–optical emission spectrometry (I CP–OES) and inductively coupled plasma–mass spectrometry (I CP–MS) technolog y provide simu ltaneous multielement det e rm i n at i ons t h at reduce anal y t i cal cost s whi l e

m a i n t a i n i n g or ex ceedi n g t h e anal y t i cal performance of earlier me thods. The elements determined by I C P–OE S and I C P–MS methods

a r e liste d a s f o llows:

INTRODUCTION 1

### Element IC P

– O E S I C P–M S Element IC P

– O E S I C P–M S

Aluminum   Ma g n e s ium 
Antimony  Mang anese  

B a rium   Moly bdenum  

B e r y llium   Ni ckel  

B o ron  S e l e n i u m 

Ca dmium   Silic on 

Ca lc ium  S i l v e r  

Chr o m i u m  Sodium 

Cobalt   Str ontium  
Copper   Tha l l i u m 

I r on  U r a n i u m 

L ead   Vanadium 

L ithium   Z i nc  

The obje c tive s of this r e por t a r e to:

 Provide a detailed desc ription of new I C P– OES and I C P–MS methods for wholewa te r dig e st a n a l y s is. De ta ile d descriptions of ope rating conditions and
pr oc e dur e s a r e c onc ise l y outline d in sections 1A-8A and 1B -8B
, respectively

.

 C o m p are t h e accuracy of I C P

– OES and I C P–MS methods to former methods of

a n a l y s is. Multiple str a te g i e s a r e use d in
t h e st at i s t i cal anal y s i s of t h e

ex perimental data to provide a practical estimate of the ex pected accuracy

.

 Compa r e the va r i a b ility of I C P–OES a nd I C P–MS methods to former methods of anal y s i s

.

 C o m p are t h e anal y t i cal perform ance of I C P–OES and I C P–MS methods.  Estima te pote n tia l e f f e c t s on long

- t e r m

wa te r

- qua lity studie s

.

 Pr ovide g u ida n c e f o r

se le c ting the most appropriate method of analy s is.

W hol e-wat e r recoverabl e el em ent s at present determined by flame–atomic absorption spectrophotometry and by direct current pla s ma –a tomic e mission spe c t r o me tr y

will be det e rm i n ed by I C P

– OES effect i v e Decem ber 1, 1998. The I C P–MS method described in this

r e por t will be imple me nte d a t a da te to be announced. The methods we re developed by the U.S. Geolog ical Survey (USGS) for use at the NW QL . These methods supplement other methods of the USGS th at are described by F i shman and F r iedman (1989) and by F i shman (1993).

AN AL Y T I C AL M E T H O D S 2AN AL Y T I C AL M E T H O D S 3 

### ANALYTICAL METHODS

Inorganic Constituents a nd Parameter Codes:

Metals, Acid Digestion, Whole-Water Recoverable, I-4471-97 Inductively coupled plasma–optical emission spectrometry

Paramétrer Lab code Parameter Lab code Parameter Lab code Aluminum,  g/L 2351 Copper,  g/L 2358 Nickel,  g/L 2365 Barium,  g/L 2352 Iron,  g/L 2359 Silica (SiO 2 ), mg/L 2366 Beryllium,  g/L 2353 Lead,  g/L 2360 Silver,  g/L 2367 Boron,  g/L 2354 Lithium,  g/L 2361 Sodium, mg/L 2368 Cadmium,  g/L 2355 Magnesium, mg/L 2362 Strontium,  g/L 2369 Calcium, mg/L 2356 Manganese,  g/L 2363 Vanadium,  g/L 2370 Cobalt,  g/L 2391* Molybdenum,  g/L 2364 Zinc,  g/L 2371 *Changed April 8, 1999. 

### Metals, Acid Digestion, Whole-Water Recoverable, I-4472-97 ( Added July 17, 2003) 

### Inductively coupled plasma–mass spectrometry

Parameter Lab code Parameter Lab code Parameter Lab code Aluminum,  g/L 2372 Copper,  g/L 2379 Silver,  g/L 2386 Antimony,  g/L 2373 Lead,  g/L 2380 Strontium,  g/L 2387 Barium,  g/L 2374 Lithium,  g/L 2381 Thallium,  g/L 2388 Beryllium,  g/L 2375 Manganese,  g/L 2382 Uranium,  g/L 2389 Cadmium,  g/L 2376 Molybdenum,  g/L 2383 Zinc,  g/L 2390 Chromium,  g/L 2377 Nickel,  g/L 2384 Cobalt,  g/L 2378 Selenium,  g/L 2385



### Inductively Coupled Plasma–Optical Emission Spectrometry

1A. Application


### This method is used to determine aluminum, barium, beryllium, boron, cadmium, calcium, cobalt, copper, iron, lead, lithium, magnesium, manganese, molybdenum, nickel, silicon (reported as silica, SiO 2 

### ), silver, sodium, strontium, vanadium, and zinc in natural wholewater digested by using the in-bottle procedure described by Hoffman and others (1996). The method detection limits (MDLs) and analytical concentration ranges are listed in table 1.MDLs were calculated by using U.S. Environmental Protection Agency’s (1994) definition and represent pooled averages on the basis of four MDLs determined on different days over several weeks.

2A. Summary of Method


### Whole-water recoverable elements are determined simultaneously on a single sample using inductively coupled plasma–optical emission spectrometry. Sample solution is pumped into a high dissolved-solids tolerant nebulizer to produce an aerosol. The aerosol is subsequently transported by argon gas through a spray chamber and torch assembly into an inductively coupled plas ma source where theT a b l e 1. F o r m er m e thods , ICP–O ES, and ICP–MS m e thod detec tion lim its and c a libr a tion lim its f o r elem ents deter m i ned in w hole- w a ter diges ts
[A ll res u lts are in m i crog ram s per liter; MDL
, m e th od detection lim it; IC P

– OES, in du ctiv ely cou p led plas m a –optical

em is s i on s p ectrom e try ; IC P

– MS, in du ctiv ely cou p led plas m a –m as s s p ectrom e try ; DC P

– A E S, direct cu rren t plas m a

– atom ic em is s i on s p ectrom e try ; GF–A A S , s t abilized tem p eratu r e g r aph ite f u rn ace–atom ic abs o rption

s p ectroph otom etry ; F–A A S , f l am e–atom ic abs o rption s p ectr o p h o t o m etry ; n a , n o t av ailab l e; n d , n o t d e term in ed ]

F o r me r me thods ICP

– OE S ICP

– M S

Elemen t T e c hnique MD L Upper limit (w ithout dilution) MD L Upper limit (w ithout dilution) MD L Upper limit (w ithout dilution)
A l um i num D C P

– A E S 1 10 10,000 14 500,000 1 1,000 A n t i m on y G F –A A S 0

. 8 2 5 n d n d 0

. 7 5 0 0 B a r i u m F

– AAS 1 100 5
, 0 0 0 0

. 5 1 0
, 0 0 0 0

. 0 8 1
, 0 0 0 B e ry lliu m F

– A A S 1 1 0 2 0 0 2 1 0
, 0 0 0 0

. 0 7 5 0 0 Boron D C P–A E S 1 1 0 1 0
, 0 0 0 1 3 1 0
, 0 0 0 n d n d C a dm i u m G F –A A S 0

. 0 6 5 5 1 0
, 0 0 0 0

. 0 5 5 0 0 Calciu m F

– A A S 1 1 0 0 6 0
, 0 0 0 5 1
, 0 0 0
, 0 0 0 n d n d C h rom i u m G F –A A S 0

. 3 2 0 n d n d 2 5 0 0 C obal t G F –A A S 0

. 4 2 5 7 1 0
, 0 0 0 0

. 0 4 5 0 0 C o p p e r G F –A A S 0

. 4 2 5 5 1 0
, 0 0 0 0

. 3 5 0 0 Iron F

– A A S 8 1,000 6 200,000 n d n d L e a d G F –A A S 0

. 4 2 5 6 0 1 0
, 0 0 0 0

. 0 5 5 0 0 L i t h i u m F

– A A S 5 1,000 8 10,000 0.04 500 M a gne si um F

– A A S 1 1 0 0 1 0
, 0 0 0 3 5 0 0
, 0 0 0 n d n d Man g a n e s e F

– A A S 4 1,000 2 25,000 0.06 1,000 Mol y bden u m G F –A A S 0

. 9 5 0 3 4 1 0
, 0 0 0 0

. 4 5 0 0 N i ck el G F –A A S 0

. 5 2 5 3 5 1 0
, 0 0 0 0

. 3 5 0 0 S e l e n i u m G F –A A S 0

. 8 5 0 n d n d 2 5 0 0 Silico n (as SiO 2 ) n a n a n a 7 0 1 0 0
, 0 0 0 n d n d S i l v e r G F –A A S 0

. 1 1 0 4 1
, 0 0 0 0

. 7 2 5 S odi u m F

– A A S 1 1 0 0 8 0
, 0 0 0 7 0 5 0 0
, 0 0 0 n d n d Str o ntium F

– A A S 1 1 0 5
, 0 0 0 0

. 5 1 0
, 0 0 0 0

. 0 4 5 0 0 T h alliu m n a n a n a n d n d 0

. 3 5 0 0 U r an i u m n a n a n a n d n d 0

. 2 5 0 0 V a n a di u m n a n a n a 5 1 0
, 0 0 0 n d n d Z i n c F

– A A S 6 500 20 25,000 0.5 1,000

1 Meth o d rep o r tin g lev e l, n o m e th o d d e tectio n lim it h a s b een estab lish e d

.



### sa mple is de solva t e d, atomiz ed, and the resultant atoms or ions ex cited. The inte nsity of lig ht e mission tha t r e sults whe n t h e ex ci t e d-st at e at om s or i ons rel a x t o t h ei r g r ound state is directly proportional to the

c onc e n tr a tion of the e mitting spe c i e s in solution. Mean concentrations of elements are report e d from t h ree repl i cat e determinations. 3A

. I n t e rf erences



### Corrective action must be taken to minimize inte r f e r e nc e s tha t mig ht le a d to i n accuraci es i n I C P

– OES resul t s , i n cl udi ng phy sical and spectral interferences.

3A.1 Physi c al i n t e rf erences: P h y s i cal i n t e rferences are g e nera lly considered to be effect s associ at ed wi t h sam p l e t r ansport and

AN AL Y T I C AL M E T H O D S 4

### ne buliza tion pr oc e sse s. Sa mple ma tr ic e s t h at are si g n i f i cant l y di fferent t h an t h e calibration standards, such as those having hig h dissolved-solid concentrations (or hig h specific conductance), mig ht cause chang e s in the tr a n spor t a nd nebuliz ation process l eadi n g t o si g n i f i cant i n accuracy i n t h e fi nal resul t

. P h y s i cal i n t e rference effect s can be overcome by using dilution or internal standards, or both. Simple dilution reduces the visc osity of the sa mple solution a nd the

c onc e n tr a tion of ma tr ix salts. Addition of a

sur f a c t a n t to the sa mple s a nd c a libr a tion
sta nda r d s a l so te nds to sta b ilize sa mple
tr a n spor t.
The use of an i n t e rnal st andard can reduce t h e effect s associ at ed wi t h chang i ng

sa mple tr a n spor t pr ope r tie s a s we ll a s instrument drift. Yttrium (371.029 nm) is commonly used as an internal standard for I C P

– OES anal y s es. The accuracy of i n t e rnal
sta nda r d iza tion r e lie s on t h e absence of
y

ttr ium in the sa mple . I f y

ttr ium is pr e s e n t,

r e sults will be ne g a tive l y bia s e d. The r e f or e , it is important to verify the absence of
y

ttr ium in the sa mple s be ing a n a l y z e d. There are several methods that can be used by the analy s t to verify its absence. The best procedure requires a rapid spectral scan of each sam p l e t o det e rm i n e i f y

t t r i u m i s present. An alternate method would be to

m oni t o r t h e y t t r i u m i n t e nsi t y i n each sam p l e duri n g t h e anal y s es. W h enever t h e y t t r i u m inte nsity is 10 pe r c e n t g r e a t e r tha n the
y

t t r i u m i n t e nsi t y for a precedi n g y t t r i u m -free S t andard R e ference W a t e r S a m p l e (S R W S )
, an unaccept a bl e l e vel of y t t r i u m i s i ndi cat ed. I n such cases, a di ffere nt internal standard element must be used.

3A.2 Spect ral i n t e rf erences: S p ect ral inte r f e r e nc e s oc c u r whe n c onstitue n ts in a

sa mple e mit r a dia tion a t wa ve le ng ths c l ose to the analy tical waveleng th being measured. Unresol v ed spect ral em i ssi on at t h e anal y t i cal

wa ve le ng th c a n r e sult in sig n if ic a n t positive bia s in the r e sults. I n some insta n c e s , the hig h concentration of an inte rferent can suppress the

e mission f r o m a n e l e m e n t a nd r e sult in a

ne g a tive bia s . Re la ting the a ppa r e nt e l e m e n ta l concentration to the concentration of the interfering element (see table 2) is used to minimize this ty pe of inte r f e r e nc e

. This r e la tion is a linear function of con c e n tr a tion tha t must be

c a libr a te d da ily . Othe r spe c t r a l inte r f e r e nc e s c a n

r e sult f r o m str a y lig ht, mole c u la r br oa dba nd emission, and spectral-lin e broadening that contribute to the backg r ound or offset in the element sig n al. B y measuring the backg r ound

em i ssi on at one or t w o posi t i ons adj acent t o t h e analy tical waveleng th, this offset can be subt ract ed from t h e si g n al (see t a bl e 3 for backg r ound measurement positions).

Ex periments were c onducted to evaluate spect ral i n t e rferences by m easuri n g el em ent responses from 10- to 100-mg /L concentrations of

nume r ous inor g a nic c onstitue n ts, inc l uding major cations (calcium, mag n esium, potassium, silica, and sodium), major anions (carbonate, chloride, nitrate, phospha te, and sulfate), and other minor elements. Elements that have sig n if ic a n t spe c tr a l inte r f e r e nc e s a r e liste d in
ta

ble 2 with the inte r f e r e nt a nd the a ppr ox ima te deg r ee of t h e i n t e rference.

Specific conductance is used to identify f ilte r e d, a c i dif i e d sa mple s tha t c a n e x hibit phy si cal i n t e rference effect s because of hi g h dissolved-solid concentrations. Since the specific conductance for a whole-water dig e st is inherently hig h but g e nerally unknown, a

ne bulize r tha t c a n tole r a te hig h dissolve d solids must be used. A Noordemeer V-g r oove

ma x imum dissolve d

- s olids ne bulize r wa s use d to obtain the data presente d in this report. Other nebuliz er desig n s can be used, but they must be resistant to clog g i ng and capable of providing

AN AL Y T I C AL M E T H O D S 5T a b l e 2. Spec tr al inter f er enc es that af f e c t elem ents deter m i ned by ICP–O ES in natur al

w hole- w a ter diges ts

[IC P

– OES, in du ctiv ely cou p led plas m a –optical e m i ssi o n sp e c t r o m e t r y ; nm , na no m e t e r ; μg /L , m i cro g ram p e r liter]

A

f f ect ed elemen t A f f ect ed elemen t s ’

an aly t ical

w a v e le ngth 1 (nm) In t e rf eren t In t e rf eren t

co n cen t r at io n (μg/L) A ppa r e nt

c onc e n tr a t ion of af

f ect ed elemen t (μg/L)

A l um i u m n 2 1 6 7

. 0 8 1 Iron 1 0 0
, 0 0 0 2 5 0 Boron 2 2 4 9

. 7 7 3 Iron 1 0 0
, 0 0 0 2 0 B e ry lliu m 3 1 3

. 0 4 2 Van a diu m 1 0
, 0 0 0 7 0 C a dm i u m 2 1 4

. 4 3 8 Iron 1 0 0
, 0 0 0 2 0 C a dm i u m 2 1 4

. 4 3 8 A l u m i n u m 1 0 0
, 0 0 0 1 5 C obal t 2 3 8

. 8 9 2 Iron 5
, 0 0 0 3 5 0 C o p p e r 3 2 4

. 7 5 4 Man g a n e s e 2 5
, 0 0 0

- 8 Iron 2 5 9

. 9 4 0 Man g a n e s e 2 5
, 0 0 0 1 0 Iron 2 5 9

. 9 4 0 S odi u m 5 0 0
, 0 0 0 3 5 L e a d 2 2 0

. 3 5 3 A l u m i n u m 1 0 0
, 0 0 0 7 5 Man g a n e s e 2 5 7

. 6 1 0 A l u m i n u m 1 0 0
, 0 0 0

- 3 0 Man g a n e s e 2 5 7

. 6 1 0 Iron 1 0 0
, 0 0 0

- 3 0 Man g a n e s e 2 5 7

. 6 1 0 Mag n e s i u m 5 0 0
, 0 0 0 1 5 S odi u m 3 3 0

. 2 2 3 Z i n c 2 5
, 0 0 0

- 6 0 V a n a di u m 2 9 2

. 4 0 2 Iron 1 0 0
, 0 0 0

- 1 0 V a n a di u m 2 9 2

. 4 0 2 Mol y bden u m 5 0 0

- 8 Zi nc 2 2 0 6

. 2 0 0 Iron 1 0 0
, 0 0 0 2 0

1 In terf eren t ef f ects are w a v e len g t h s p ecif i c.

2 W a ve l e ngt h i s se c o nd o r d e r



### .

method detection limits with in a factor of two of those listed in table 1.

4A

. A pparat u s, I n st rument at i on, and O p erat i ng Condi t i ons



### 4A.1 Labware: Use cl ean Ty pe A g l ass volumetric flasks to prep are all solutions. Store solutions in fluorinated ethy lene propy lene ( F EP Te f l on) bottle s to ma inta in sta b le el em ent a l concent r at i ons. R e g u l a rl y veri fy
accuracy of al l pi pet s and vol um et ri c fl asks used to prepare standard solutions with either an anal y t i cal bal a nce or an aut o m a t i c calibrating spectrophotometer. 4A.2 Instrumentation: A Thermo J a rrell-Ash (TJ A ) arg on or nitrog en purg e d spectrometer with a 0.75-m focal leng th and spectrum shifter backg r ound correction was used in this method. The arg on plasma was
g e nerated using 27.12 MHz energ y

. Accessories included a TJ A Model AS300

a

u tosa mple r , Gilson pe r i sta ltic pump, TJ A internal standards kit (Part #13670800), and computer data sy stem. A Noordemeer Vg r oove nebuliz er was used because of its

a

b ility to r e sist c l og g i ng whe n a n a l y z ing

sa mple s with hig h dissolve d

- s olid concentrations.

AN AL Y T I C AL M E T H O D S 6T a b l e 3. Analy t ic al w a velengths and bac k g r ound c o r r e c t ion points us ed f o r the deter m i nation of elem ents in w hole- w a ter diges ts by ICP–O E S

[IC P

– OES, in du ctiv ely cou p led plas m a –optical em i s s i on s p ectrom e try ; n m , n a n o m e ter; on e s p ectru m

s h i f t e r s t ep equ a l s abou t 0.008 n m ]

Elemen t Wa v e le ngth 1 (nm) Background

c o r r e c t ion point 3 ( s p ect ru m sh if t e r st ep s)
A l um i num ( 1 ) 2 1 6 7

. 0 8 1 1 2 A l u m i n u m (2) 308.215 12 Bari u m 4 5 5

. 4 0 3

- 1 1 B e ry lliu m 3 1 3

. 0 4 2

- 1 1 Boron 2 2 4 9

. 7 7 3 1 2 C a dm i u m 2 1 4

. 4 3 8

- 1 1 C a l c i u m (1) 396.847

- 11 C a l c i u m (2) 315.887 12 C h rom i u m 2 6 7

. 7 1 6

- 1 1 C obal t 2 3 8

. 8 9 2 1 2 C o p p e r 3 2 4

. 7 5 4 1 2 Iron 2 5 9

. 9 4 0 1 2 L e a d 2 2 0

. 3 5 3

- 1 1 L i t h i u m 6 7 0

. 7 8 4 n o n e Mag n e s i u m (1) 279.553 12 Mag n e s i u m (2) 383.231

- 11 Man g a n e s e 2 5 7

. 6 1 0

- 1 1 Mol y bden u m 2 0 3

. 8 4 4 1 2 Nick el 2 2 3 1

. 6 0 4

- 1 1 Silico n , as SiO 2 2 8 8

. 1 5 8 1 2 S i l v e r 3 2 8

. 0 6 8

- 1 1 S odi u m (1) 588.995 n o n e S odi u m (2) 330.223

- 11 S t ron t i u m 4 2 1

. 5 5 2

- 1 1 V a n a di u m 2 9 2

. 4 0 2

- 1 1 Y t t r i u m 3 7 1

. 0 2 9

- 1 1 Zi nc 2 2 0 6

. 2 0 0 1 2

1 W a v e len g t h s are in s t ru m e n t an d m e th od s p ecif i c.
2 W a ve l e ngt h i s se c o nd o r d e r

. 3 Sh if t relativ e to in d i cated w a v e len g t h ; a sh if t to a lo w e r w a v e len g t h is id en tif ied b y th e m i n u s sig n

.



### The waveleng ths used to measure

e l e m e n ta l c onc e n tr a tions a r e liste d in ta ble 3. Two anal y t i cal wavel e ng t h s are l i s t e d for aluminum, calcium, mag n esium, and sodium. These waveleng ths are listed in order of the

e mission inte nsity ; the r e f or e , the f i r s t wa ve

le ng th is the mor e se nsitive

. The r e is some

ove r l a p in the c a libr a tion c u r v e s f o r

the two waveleng ths; hence a ra ng e of concentrations can be quantified with e ither waveleng th. Uppe r a nd lowe r c onc e n tr a tion limits f o r

both

wa ve le ng ths a r e de te r mine d by the line a r ity of their response. These concentration limits and overlap reg i ons are listed in table 4. The analy s t or data sy stem deter mine s whic h e mission line results should be repor ted on the basis of elemental concentrati on, quality -control results, and t h e presence of i n t e rferences.

AN AL Y T I C AL M E T H O D S 7T a b l e 4. Upper and low e r c onc entr a tion lim it and c onc entr a tion over lap r egion f o r ICP–O ES elem ents having dual em is s i on w a velengths
[IC P

– OES, in du ctiv ely cou p led plas m a –optical em i s s i on s p ectrom e try ; all con cen tration s are in

m illig ram s p e r liter, ex cep t f o r alu m in u m , w h ich is in m i cro g ram s p e r liter; th e o v erlap reg i o n is th e

con cen tration ran g e w h ere res u lts f r om eith er em is s i on w a v e len g t h can be reported; MDL
, m e th od d e tectio n lim it (see tab l e 1 )]

Co n cen t r at io n limit s

Elemen t 1 Low e r Uppe r Ov e r la p r e gion (us e

w a v e le ngth 1 or 2 )

A l um i num ( 1 ) A l um i num ( 2 ) M D L 300 75,000 500,000 300 t o 75,000
Calciu m (1 ) Calciu m (2 ) M D L 6 25 1,000 6 t o 25
M a gne si um ( 1 ) M a gne si um ( 2 ) M D L 6 100 500 6 t o 100
S odiu m (1) S odiu m (2) M D L 50 125 500 50 t o 125

1 Co rresp o n d i n g w a v e len g t h s are listed in tab l e 3

.



### 4A.3 Operating conditions:

 Inductively coupled plasma operating conditions—

Optimiz ed operating conditions are liste d a s f o llows. The s e se tting s a r e ba se d

on e x pe r ime nts tha t ma x imize the sig n a l to noi se rat i o for severa l atomic emission and ionic emission waveleng th s that have different ioniz a tion potentials as a function of incident power, horiz ontal observation position, and

sa mple de live r y

r a te

.

In ci den t radi o f r equ e n c y pow er ~ 0.95 k W R e f l ected radio f r equ e n c y pow er ~ 0 W T o r c h ga s fl o w r a t e ~ 1 4 L/ m i n ( h i gh) A u x iliary f

l o w rate ~ 1

. 0 L / m i n N e bu l i zer pres s u re ~ 45 l b / i n 2 (~3.2 ki l o gr a m s/ sq ua r e

cen tim eter) S a m p l e f l ow rat e (t o n e bu l i zer) ~ 2.9 m L / m i n Ho rizo n t al o b s erv a tio n p o s itio n ~ 1 5 m m

ab o v e lo ad co il Vertical o b s erv a tio n p o s itio n Cen t er 

###  Internal standard manifold

— Yttr ium is use d a s the inte r n a l sta nda r d. Othe r e l e m e n ts ma y be substitute d if ne e d e d ; howe v e r , the c hoic e s a r e limite d to the

e l e m e n ta l wa ve le ng ths pr e s e n t on the instrument. The intern al standard introduction
sy stem is based on a modified TJ A internal standard kit (TJ A item # 13670800). The
pe r i sta ltic pump tubing pr ovide d in the kit wa s modified to achieve the overall lowest possible MDL s using the Noordemeer V-g r oove nebuliz er. The manifold sy stem is shown in fig u re 1a (see Appendix )

.

 Data ac quisition

—

Two m easurem ent s are m a de for every el em ent , one at t h e anal y t i cal wavel e ng t h

m a x i m u m and one adj acent t o t h e anal y t i c al waveleng th (backg r ound correction). Bo t h measurements consist of three 5-second inte g r a tions.

AN AL Y T I C AL M E T H O D S 8

###  Interelement correction factors—

I n t e rel e m e nt correct i on fact ors are used
t o adj u st for apparent i n creases or decreases i n a si g n al because of unresol ved spect ral i n t e rferences (see section 3A.2 and table 2).

 Background correction protocol

— The backg r ound adjacent to the anal y t i cal wavel e ng t h s i s m easured t o minimiz e spectral backg r ound interferences. B ackg r ound correction points are listed in table 3.

 Optimization of primary refractor plate position ( p rofile )—

I n str u me nt pr of ile is a d juste d to within 0.1 spectrum shifter steps of the ma x imum pe a k intensity for mercury at 435.835 nm

.



###  Aut o sampl e r cycl es

— Spe c i f i e d c y c l e time s ha ve be e n shown to minimize me mor y

e f f e c t s f r o m sa mple s containing all elements up to the upper calibration standard (s ee table 1) and boron up to 5,000  g / L

. The le ng th of the c y c l e time s is dependent on the sample introduction sy stem being used. I f the sa mple introduction sy stem described in this method is modified, these time s like l y will r e quir e a d justme nt.

Rinse cy cle ~ 25 seconds F l ush cy cle ~ 90 seconds

5A

. Reagent s and Cal i b rat i on St andards



### AS TM Ty pe I reag ent wat e r (Am e ri can Society for Testing and Materials, 1995, p. 122–124), spectroscopic g r ade commercial standards, and ultrapure acids must be used to prepare al l sol u t i ons. Al l percent a g e s represent volume-to-volume ratios. All concentrated acids and commercial standa rds must be verified
to c onta i n c onc e n tr a tions of c onc omita nt el em ent s t h at are l e ss t h an t h e MDL s aft e r t h e prescribed dilution. Every solution must be
stor e d in a de sig n a t e d c l e a n F E P Te f l on bottle ; solutions that contain silver must be stored in a de sig n a t e d c l e a n opa que F E P Te f l on bottle

.

5A.1 Nitric ac id (HNO 3 

### ): Concentrated, specific g r avity 1.41.

5A.2 Hydrochloric acid(HCl): Concentrated, specific g r avity 1.196.

5A.3 Calibration blank and rinse solution , AS TM Ty pe I reag ent wat e r aci di fi ed to 0.4 percent nitric acid and 2 percent hy drochloric acid.

5A.4 C o mmerci a l si ngl e-el ement standard solutions , 1.00 mL = 10 mg preserved in nitric acid for each of the following : Al, Ag
, B a , B e , Ca, Cd, Co, Cr, Cu, F e , L i , Mg , Mn, Na, Ni, Pb, Sr, and Z n.

5A.5 C o mmerci a l si ngl e-el ement standard solution , 1.00 mL = 5 mg vanadium preserved in nitric acid.

5A.6 C o mmerci a l si ngl e-el ement standard solution , 1.00 mL = 10 mg moly bdenum preserved in hy drochloric acid.

5A.7 C o mmerci a l si ngl e-el ement standard solution , 1.00 mL = 5 mg boron in
water.

5A.8 C o mmerci a l si ngl e-el ement standard solution , 1.00 mL = 10 mg silicon in
water.

5A.9 C o mmerci a l si ngl e-el ement standard solution , 1.00 mL = 10 mg y ttrium preserved in nitric acid.

5A.10 Brij- 35 (CAS 9002-92-0), 30 percent solution of poly o x y ethy lene laury l ether.

AN AL Y T I C AL M E T H O D S 9

### 5A.11 Multielement calibration standard I

, 1.00 mL = 5.0  g of Cd, Cr, Pb, and Z n ; 1.00 mL = 50.0  g F e . Dilute 0.5 mL (ex cept for F e , use 5.0 mL ) of each comme rcial sing le-element standard to 1,000 mL in a volumetric flask with calibration blank.

5A.12 Multielement calibration standard II

, 1.00 mL = 5.0  g of B a , B e , Co, Cu, Ni, Sr, and V. Dilute 0.5 mL of each commercial sing le-element standa rd to 1,000 mL in a volumetric flask with calibration blank.

5A.13 Multielement calibration standard III , 1.00 mL = 4.0  g of Ag ; 1.00 mL = 5.0  g of L i and Mo; 1.00 mL = 10.0  g of Ca. Dilute 0.4 mL of the commercia l Ag standard, 0.5 mL of the commercial L i a nd Mo standard, and 1.0 mL of the commercial Ca standard to 1,000 mL in a volumetric flask with calibration blank.

5A.14 Multielement calibration standard IV , 1.00 mL = 5.0  g of Mn; 1.00 mL = 50  g of Ca and Na. Dilute 5.0 mL (ex cept for Mn, use 0.5 mL ) of each comme rcial sing le-element standard to 1,000 mL in a volumetric flask with calibration blank.

5A.15 Multielement calibration standard V

, 1.00 mL = 10.0  g of Mg and Na; 1.00 mL = 50.0  g of Al. Dilute 1.0 mL of the

c o mme r c ia l sing le

- e le me nt sta nda r d ( e x c e p t f o r Al, use 5.0 mL ) to 1,000 mL in a volumetric flask with calibration blank.

5A.16 Multielement calibration standard VI , 1.00 mL = 5.0  g of B and Si. Dilute 0.5

m L of each com m e rci a l si ng l e -el e m e nt standard to 1,000 mL in a volumetric flask with calibration blank.

5A.17 Perf ormance check sol u t i o n , 1.00 mL = 5.0  g of Ag , Al, B
, B a , B e , Ca, Cd, Co, Cu, F e , L i , Mg , Mn, Mo, Na, Ni, Pb, Si, Sr, V, and Z n. Dilute 0.5 mL of each commercial sing le-element standar d, ex cept dilute B and V using 1.0 mL , to 1,000 mL in a volumetric flask with calibration blank.

5A.18 Spect ral i n t e rf erence check solution I , 1.00 mL = 100  g of F e . Dilute 10.0 mL of the c o mme r c ia l sing le

- e le me nt sta nda r d to 1,000 mL in a volumetric flask with calibration blank.

5A.19 Spect ral i n t e rf erence check solution I I

, 1.00 mL = 5.0  g of F e and V; 1.00 mL = 500  g of Mg . Dilute 0.5 mL of the

c o mme r c ia l F e sta nda rd, 50 mL of the commercial Mg standar d, and 1.0 mL of the commercial V standard to 1,000 mL in a volumetric flask with calibration blank.

5A.20 Spect ral i n t e rf erence check solution I I I

, 1.00 mL = 500  g of Al and Na; 1.00 mL = 5.0  g of Mo. Dilute 50 mL of each

c o mme r c ia l sing le

- e le me nt sta nda r d ( e x c e p t f o r Mo, use 0.5 mL ) to 1,000 mL in a volumetric flask with calibration blank.

5A.21 Spect ral i n t e rf erence check solution I V , 1.00 mL = 25  g of Mn; 1.00 mL = 5.0  g of Z n. Dilute 2.5 mL of the commercial Mn standard and 0.5 mL of the commercial Z n standard to 1,000 mL in a volumetric flask with calibration blank.

5A.22 Internal standard working solution , 1 mL = 5  g Y. Dilute 0.5 mL of

c o mme r c ia l sing le

- e le me nt sta nda r d f

o r

Y a nd 200  L B r ij-35 solution to 1,000 mL in a volumetric flask with calibration blank.

6A

. A n al y t i cal Procedure



### Refer to Thermo J a rrell-Ash (1991) for de ta ils of pr oc e dur e s outline d in the f o llowing
parag r aphs.

6A.1 Set up the instrument using the operating conditions desc ribed in section 4A.3

AN AL Y T I C AL M E T H O D S 10

### a nd ig nite the pla s ma . Allow the instr u me nt to warm up for at least 30 minutes prior to optimiz ation.

6A.2 Start the ThermoSPEC software.

6A.3 Edit a n a u tosa mple r ta ble with the unknown sample identifiers. L o ad the autosampler with calibration blank, multie le me nt c a libr a tion sta nda r d s, qua lity

a ssur a nc e / qua lity c ontr o l ( QA/QC) sa mple s, and unknown samples.

6A.4 Turn on the instrument-mounted
mercury pen lamp, move it in front of the

e n tr a n c e slit, a nd e x e c u te the pr of ile option in the The r moSPEC sof t wa r e . Adjust the me r c ur y profile until the peak position is within ± 0.1
spe c t r u m shif te r ste p s. Sta r t c a libr a ting the instr u me nt.

6A.5 Veri fy t h e accuracy of t h e

c a libr a tion by using the r e sults f r o m the i n st rum e nt perform ance check sol u t i on (see section 5A.17) and calibration blank. I n st rum e nt perform ance check sol u t i on concentrations must not deviate from the theoretical concentrations by more than ±5
pe r c e n t, a nd the r e la tive standard deviation of the r e plic a t e inte g r a tions must be le ss tha n 4 percent

. I f t h e error ex ceeds ±5 percent
, reanal y z e t h e i n st rum e nt perform ance check solution. I f error still ex ceeds the criterion, the instr u me nt must be r e c a libr a te d. Re la tive standard deviations g r eater than 4 percent for
t h e i n st rum e nt perform ance check sol u t i on most like l y indic a t e pr oble m s with sa mple introduction. W h enever the variability is poor, the ne bulize r , pe r i sta ltic pump, a nd transmission tubing must be checked and the instr u me nt r e

- c a libr a te d.

Calibration blank concen trations must be within ±12 percent of the current MDL s . I f any

r e sult is outside this limit, r e a n a l y z e the calibration blank. I f a result is still outside the limit, use a nothe r c a libr a tion bla nk solution a nd

r e c a libr a te the instr u me nt.
6A.6 Verify that in te r e le me nt c o r r e c tion fact ors are accurat e by usi n g resul t s from t h e spect ral i n t e rference check sol u t i ons (see sections 5A.18–21). I f the concentration for any el em ent t h at i s affect ed by spect ral i n t e rference deviates by more than ±12 percent from the current MDL s , a new in te r e le me nt c o r r e c tion fact or for t h at el em ent m u st be est a bl i s hed before continuing sample analy s es. A “UDEL ETE” (unable to analy z e) code will be reported instead of coba lt c onc e n tr a tions f o r samples that have iron concentration g r eater than or equal to 2,000  g / L because of t h e l a rg e spe c t r a l inte r f e r e nc e f r o m ir on e mission on the cobalt analy tical waveleng th. W h enever iron concentrations ex ceed 2,000  g / L
, t h e accuracy of

the inte r e le me nt c o r r e c tion be c o me s unaccept a bl e.
6A.7 The QA/QC plan requires analy s is of at least one of the following solutions at a frequency of at least 1 in every 10 unknown samples: SRW S , calib ration blank, duplicate

sa mple , dilute d sa mple , or ma tr ix spike

. I f S R W S s are used, t h e anal y s t m u st ensure t h at

r e sults f a ll within the e s ta blishe d qua lity

- c ontr o l limits. Selection of a suitable SRW S should be based on t h e ex pect ed sam p le concentration rang e.

6A.8 I f al l dat a -accept a nce cri t e ri a are

sa tisf i e d, the n the a n a l y tic a l r e sults a r e accept a bl e. I f any one cri t e ri on i s not sat i s fi ed, the n the a n a l y s t must r e a n a l y z e the sa mple in question. I f the results remain outside the

c r ite r i a , the instr u me nt must be r e c a libr a te d a nd

a ll sa mple s f o llowing the la st a c c e p ta ble QA/ QC check reanal y z ed. For sel e ct ed elements, the upper calibration limit does not represent the endpoint of the linear rang e but

r a the r a

c onc e n tr a tion limit mor e a ppr opr ia te f o r the ma jor ity of sa mple s a n a l y z e d. Ne ve r t he le ss, if an elemental result is g r eater than the upper

c a libr a tion limit, the sa mple must be dilute d

AN AL Y T I C AL M E T H O D S 11

### ( w ith the c a libr a tion bla nk) , so tha t the elemental result will be less than the upper

c a libr a tion limit, a nd r e a n a l y z e d.

7 A . C a lc u l a t io n s



### 7A.1 Conc e n tr a tions a r e a u toma tic a lly calculated by the instrument’s computer sof t wa r e . He a d ing s ide n tif y

the r e sults.

7A.2 I f sa mple s we r e dilute d, multiply results by appropriate d ilution f a c t or using the computer software.

7A.3 F o rmulas used to calculate percent spike r e c ove r y

f

o r

the ma tr ix spike a nd pe r c e n t di fference for dupl i cat es are provided in the standard operating procedure (SOP; T.M. Str u ze ski, U.S. Ge olog ic a l Sur v e y , wr itte n commun., 1998).

8A

. Report i ng of Resul t s


### The number of sig n ificant fig u res reported in the r e sults va r i e s with e l e m e n t a nd is a function of concentration. W h enever the

e l e m e n ta l c onc e n tr a tion is le ss tha n the MDL
, the r e sult is r e por te d a s le ss tha n the MDL ( < MDL ) . All other elemental results for wholewater dig e sts are reported by use of the criteria l i s t e d bel o w. These cri t e ri a are based on t h e uncertainty indicated in table 17. Alternatively
, the va r i a b ility a ssoc i a t e d with the me a n concent r at i on (report e d wi t h t h e m ean by each i n st rum e nt ) m easured i n each sam p l e coul d be

use d to e s ta blish the appropriate number of sig n ificant fig u res to report. The use of such a procedure woul d provi de t h e m o st accurat e estimate of the uncertainty associated with each unique sa mple ma tr ix

.
For barium and strontium—

 I f t h e concent r at i on i s g r eat er t h an or equal to the MDL
, but less than 100  g/ L
, t h e n report result to the nearest 0.1  g/ L

.  I f the concentration is g r eater than 100
 g / L
, but less than 1,000  g / L
, the n r e por t r e sult to
t h e nearest 1  g/ L

.

 I f the concentration is g r eater than 1,000
 g / L
, the n r e por t r e sult to the ne a r e s t 10  g/ L

. For aluminum, beryllium, boron, cadmium, cobalt, copper, lithium, manganese, molybdenum, nickel, silver, vanadium, and zinc—

 I f t h e concent r at i on i s g r eat er t h an or equal to the MDL
, but less than 100  g/ L
, t h e n

r e por t r e sult to the ne a r e s t 1  g/ L

.

 I f the concentration is g r eater than 100
 g / L
, the n r e por t r e sult to the ne a r e s t 10  g/ L

.

N O TE: W h enever the concentration of iron is
g r eater than or equal to 2,000  g / L
, an “UDEL ETE” (unable to analy z e) code will be reported for cobalt (see section 6A.6).

For lead—

 I f t h e concent r at i on i s g r eat er t h an or

e qua l to the MDL
, the n r e por t r e sult to the ne a r e s t 10  g/ L

. For calcium, iron, magnesium, and sodium—

 I f t h e concent r at i on i s g r eat er t h an or

e qua l to the MDL
, but le ss tha n 1 mg /L , the n report result to the nearest 0.001 mg /L

.

 I f t h e concent r at i on i s g r eat er t h an or equal to 1 mg /L , but less than 10 mg /L , then report result to the nearest 0.01 mg /L

.

 I f t h e concent r at i on i s g r eat er t h an or equal to 10 mg /L , but less than 100 mg /L , then report result to the nearest 0.1 mg /L

.

AN AL Y T I C AL M E T H O D S 12

###  I f t h e concent r at i on i s g r eat er t h an or equal to 100 mg /L , then report result to the

ne a r e s t 1 mg /L

.
For silic on ( r e

porte d as SiO 2 

### )—

 I f t h e concent r at i on i s g r eat er t h an or

e qua l to the MDL
, but le ss tha n 1 mg /L , the n report result to the nearest 0.01 mg /L

.

 I f t h e concent r at i on i s g r eat er t h an or equal to 1 mg /L , but less than 10 mg /L , then report result to the nearest 0.1 mg /L

.

 I f t h e concent r at i on i s g r eat er t h an or equal to 10 mg /L , but less than 100 mg /L , then

r e por t r e sult to the ne a r e s t 1 mg /L

.
Inductiv e ly Coupled Plasma–Mass Spectrometry

1B. A ppl i cat i on



### This method is used to determine recoverable aluminum, antimony , barium, bery llium, cadmium, chromium, cobalt, copper, le a d, lithium, ma ng a n e s e , moly bde num, nic k e l
, se le nium, silve r , str ontium, tha llium, ur a n ium, and z i nc in natural whole

- wa te r sa mple s dig e ste d by using the in- bottle pr oc e dur e tha t is described by Hoffman and others (1996). The MDL s and anal y t i cal concent r at i on rang es are listed in table 1. The method calibration rang es

we r e optimize d f

o r

e l e m e n ta l c onc e n tr a tions normally found in natura l water, however, the dy namic rang e for I C P-MS is linear to a

max imum of about 1 mg /L for elements that are monoisotopic, and somewhat g r eater than 1
mg /L f o r

e l e m e n ts tha t ha ve multiple isotope s. MDL s were calculated by using U.S. Environmental Protection Ag ency ’s (1994) definition and represent pooled averag es on the basis of four MDL s th at were determined on different day s over several weeks. 2B. Summary of M e t hod



### W hol e-wat e r recoverabl e el em ent s are de te r mine d simulta ne ously on a sing le sa mple by using inductively coupled plasma–mass spectrometry

. An aerosol of the sample solution is produced by using a hig h dissolved-solids tolerant nebuliz er. Th e aerosol is introduced into the arg on plasma where it underg oes desolvation, atomiz ation, and ioniz a tion. I ons

a r e sa mple d thr oug h multiple or if ic e s into the quadrupole mass spectrometer where they are separated on the basis of the i r ma ss- to- c ha r g e

r a tios. An e l e c t r on multiplie r de te c t s the ions by
g e nerat i n g an el ect ri cal current t h at i s di rect l y proportional to the concentration of the element
pr e s e n t in the sa mple . A mor e de ta ile d description of I C P–MS th eory and application is described in Montaser and Golig htly (1992) and B oumans (1987a and 1987b).

3B. I n t e rf erences


### Several ty pes of phy si cal and spect ral i n t e rference are recog n i z ed and docum ent e d for I C P–MS techniques. Phy s ic a l inte r f e r e nc e s a r e associated primarily w ith sample introduction

a nd a r e minimize d by using the inte r n a l standardiz ation technique. I s otopes measured in
t h i s procedure have been sel ect ed speci fi cal l y t o minimize spe c t r a l inte r f e r e nc e s f r o m isoba r i c , doubly charg e d, and molecular ions. Multiple i s ot opes can be m easured for sel ect ed el em ent s that have potential isobaric or molecular ion inte r f e r e nc e s . Da ta f

r o m multiple isotope s c a n i ndi cat e t h e presence and m a g n i t ude of interferences. The analy s t must be conscious of
t h ese i n t e rferences because t h ey m i g ht occur with c e r ta in ty pe s of sa mple ma tr ic e s

.

3B .1 Physi c al i n t e rf erences: The effect s of

sa mple tr a n spor t, in strumental drift, and

ma tr ix

- i nduc e d f

l uc tua tions in pla s ma charact e ri st i c s are reduced by usi n g t h e rat i o of

e l e m e n ta l ion inte nsity to the inte r n a l sta nda r d element ion intensity for calibration. Accurate

AN AL Y T I C AL M E T H O D S 13

### results depend on having a constant internal standard ion intensity throug hout the analy s is of all standards and sa mple s. Consta nt inte r n a l standard ion intensity requires that any i n t e rferences associ at ed wi t h t h e i n t e rnal
st andard el em ent can be correct ed and t h at t h e inte r n a l sta nda r d e l e m e n t is not na tur a lly
pr e s e n t in the sa mple s be ing a n a l y z e d.

Three isotopes that ex tend the mass rang e from 6 to 240 atomic mass units (amu) are used as internal standards—in this method 45 

### Sc +



### , 115 

### In + 

### , and 209 

### Bi + 

### are routinely used. Alte r n a tive isotope s ma y be substitute d a f te r ensuri ng t h at t h ere are no spect ral i n t e rferences associ at ed wi t h t h e new sel ect i ons. Anal y t i cal isotopes less than 45 amu are normaliz ed to
45 

### Sc + 

### , and those g r eater than 209 amu are

nor ma lize d to 209 

### Bi + 

### . Analy tical isotopes between 45 and 115 amu are normaliz ed by using a response obtained from the linear interpolation of the responses for 45 

### Sc + 

### and
115 

### In + 

### . Similarly
, isotopes between 115 and 209 amu are normaliz ed by using an interpolated response based on 115 

### In + 

### and 209 

### Bi +



### .

Me mor y

e f f e c t s tha t a r e r e la te d to sa mple
tr a n spor t a r e ne g lig ible f o r

most e l e m e n ts

nor ma lly pr e s e n t in na tur a l whole

- wa te r dig e sts. Carry over from samples that have elemental concentrations less than 1,000  g/ L is ne g lig ible f o r

a ll e l e m e n ts e x c e p t a n timony

. Antimony concentrations g r eater than 50  g/ L can produce substantial carry over in subsequent

sa mple s. Ana l y s e s f o llowing sa mple s tha t ha ve elemental concentrations g r eater than 1,000
 g / L must be reanaly z ed to verify that

c a r r y ove r wa s ne g lig ible

.

3B .2 Spect ral i n t e rf erences: W h enever possible
, the isotope use d f

o r

qua ntita tion ha s no spect ral i n t e rferences or has a small number of

pote n tia l spe c t r a l inte r f e r e nc e s tha t is unlikely to occur in whole-water dig e sts or can easi l y be correct ed. S p ect ral i n t e rferences can orig inate from isobaric ions, molecular ions, or doubly charg e d ions. The analy s t must be aware of t h ese pot ent i a l spect ral i n t e rferences when revi ewi n g anal y t i cal resul t s . S p ect ral overl ap contributions caused by insufficient abundance

se nsitivity a r e ne g lig ible a nd c a n be minimize d by m easuri n g each i s ot ope at t h ree poi nt s t h at tr a n se c t the pe a k ma x imum, whic h is c e n te r e d a t the nominal mass. The known interferences for the elements that are determined in this method

a r e liste d be low.

3B .2.1 Isobaric interferences: There are only three isobaric interferences for isotopes measured in this method— 82 

### Kr + 

### on 82 

### Se +



### , 114 

### Sn +



### on 114 

### Cd + 

### , and 115 

### Sn + 

### on 115 

### In + 

### . Kry p ton can be a minor contaminant found in arg on g a s used to support the plasma, however, its concentration will r e ma in c onsta nt f o r

both the sta nda r d s a nd samples, and, therefore, usually does not require correction.

The most abundant cadmium isotope
114 

### Cd + 

### is used as a secondary isotope and is subject to isobaric overlap from 114 

### Sn + 

### . The following equation must be used to calculate the ion intensity corresponding to only 114 

### Cd + 

### :

114 Cd + = I114 – [I118 X ( 114 Sn/ 118 Sn) ] 

### (1)

or

114 

### Cd + 

### = I 114 – (I 118 X 0.02707) , ( 

### 2)

where I 114 and I 118 are the ion intensities measured at 114 and 118 amu, respectively
, and 114 

### Sn/ 118 

### Sn is the r a tio of the na tur a l abundance of the two tin isotopes (this ratio is based on the assumpti on of natural abundance). Thi s i s obari c correct i on i s accept a bl e f o r

tin c onc e n tr a tions le ss than or equal to 2

m g / L . I f t i n concent r at i ons ex ceed 2 m g / L
, then only 111 

### Cd + 

### results can be considered.

I ndium is routinely used as an internal standard. W h enever tin is present in a sample, its isoba r i c inte r f e r e nc e on 115 

### In + 

### isotope is

e limina t e d by using the f o llowing e qua tion:

AN AL Y T I C AL M E T H O D S 14115 

### In + 

### = I 115 – [ I 118 X ( 115 

### Sn/ 118 

### S n )] (3)

or

115 

### In + 

### = I 115 – (I 118 X 0.01416) , (4)

where I 115 and I 118 are the ion intensities measured at 115 and 118 amu, respectively
, and 115 

### Sn/ 118 

### Sn is the r a tio of the na tur a l abundance for the g i ven tin isotopes. This i s obari c correct i on i s accept a bl e for t i n

c onc e n tr a tions le ss tha n or equal to 2 mg /L

. I f

t i n concent r at i ons ex ceed 2 m g / L , an al t e rnat e i n t e rnal st andard el em ent , such as rhodium ( 103 

### Rh + 

### ), can be used.

3B .2.2 Mol ecul a r i on i n t e rf erences: There are several known molecular ion i n t e rferences associ at ed wi t h el em ent s det e rmined in this method. Molecular ions, for

ex am pl e, C e O + 

### , ClO + 

### , and NaAr + 

### , are produced within the ex pansion z one behind the interface. Mole c u la r ion spe c t r a l inte r f e r e nc e s a r e liste d in table 5 as apparent el em ent a l concent r at i ons corresponding to a g i ven concentration of interferent with the ionic species responsible for t h e i n t e rference.

Mole c u la r ion inte r f e r e nc e s on 52 

### Cr + 

### and
53 

### Cr + 

### from 40 

### Ar 12 

### C + 

### and 40 

### Ar 13 

### C + 

### , respect i v el y , have been found to be neg lig ible. The interference on 53 

### Cr + 

### from 38 

### Ar 15 

### N + 

### also is
neg lig ible because ofthe low natural abundance of the arg on and nitrog en isotopes. I n t e rferences on chrom i u m t h at are associ at ed with c h lor o

- o x y g e n spe c i e s a r e minimize d by

ma tr ix

- m a t c h ing the c a libr a tion sta nda r d s to the same percentag e of hy drochloric acid as the in- bottle dig e sts, howe v e r , the ma tr ix ma tc hing

m u st be accurat e

.
Sulfur and ox y g en isotopes form molecular ions of S 2 + 

### , SO + 

### , and SO 2 + 

### tha t interfere with chromium, copper, selenium, and

z i nc determinations. Sulf ur

mole c u la r ions arise from sulfide, sulfite, or sulfate, althoug h in whole-water dig e sts, sulfate is the primary form. The inte r f e r e nc e on se le nium a nd c h r o mium is

ne g lig ible f o r

sulf a t e c onc e n tr a tions le ss tha n 1,000 mg /L . However, sulfur molecular ion interferences can sig n ific antly affect copper and

z i nc results. Errors associated with these i n t e rferences are correct ed by cal i b rat i n g t h e apparent copper and z i nc concentrations to sulfate concentration. Apparent 65 

### Cu + 

### and 66 

### Zn + 

### concentrations are linear throug h 1,000 mg /L sulfate based on the instrument response at
32 

### S 16 

### O + 

### (see fig s . 2a–b in Appendix )

. I n strument response at 32 

### S 16 

### O + 

### as a function of sul f at e concent r at i on i s represented best by a poly nomial equation for c onc e n tr a tions le ss tha n 1,000 mg /L (see fig

. 3 in Appendix ) , however, the response is linear at less than 600 mg /L

. Using 32 

### S 16 

### O + 

### to qua ntita te sulf a t e inte r f e r e nc e s requi res correct i on for unr esolved contributions from 48 

### Ca + 

### (0.19 percent abundance) and 48 

### Ti + 

### (73.8 percent abundance). These contributions are det e rm i n ed by m easuri n g 43 

### Ca + 

### and 47 

### Ti + 

### and calculating the corresponding effect at 48 amu using the following equations:

48 

### Ca + 

### = I 43 

### X ( 48 

### Ca / 43 

### Ca) = I 43 

### X 1.36 

### (5)

48 

### Ti + 

### = I 47 

### X ( 48 

### Ti/ 47 

### T i ) = I 47 

### X 10.1 

### (6)

32 

### S 16 

### O + 

### = I 48 – 48 

### Ca +


### – 48 

### Ti +



### , 

### (7)

where I 43, I 47, and I 48 are the ion intensities measured at 43, 47, and 48 amu, respectively
, and
48 

### Ca / 43 

### Ca and 48 

### Ti/ 47 

### Ti a r e the r a tios of the na tur a l abundance for the g i ven isotopes. This correction method is problematic b ecause calcium concentr a tion c a n be r e la tive l y hig h in whole-water dig e sts. I n the a b se nc e of c a l c i um or tita nium, subtracting the apparent c onc e n tr a tion f r o m the orig inal concentration (25  g / L copper and z i nc)
g i ves a correct ed concent r at i on of accept a bl e accuracy (see fi g s . 4a–b i n Appendi x )

.

AN AL Y T I C AL M E T H O D S 15T a b l e 5. Molec u lar ion inter f er enc es f o r elem ents deter m i ned in w hole- w a ter diges ts by ICP–MS

[IC P

– MS, in du ctiv ely cou p led plas m a –m as s s p ectrom e try ;  g / L
, m i cro g ram p e r liter; m g /L , m illig ram p e r liter; ~, ap p r o x im ate; <, less th an ; MDL
, m e th o d d e tectio n lim it; >, g r eater th an ]

Is otope 1 Prim ary in t e rf eren t In t e rf eren t ion or ions In t e rf eren t

co n cen t r at io n A ppr ox ima t e
a ppa r e nt elemen t

co n cen t r at io n (μg/L)

52 Cr Chlo r i d e 35 Cl 16 OH + 100 m g / L C l ~0.2

52 Cr Su lf ate 36 S 16 O + 1,000 m g / L S O 4 2

~ 2

53 Cr Chlo r i d e 37 Cl 16 O +
, 35 Cl 18 O + 100 m g / L C l ~0.2

53 Cr Su lf ate 36 S 16 O + 1,000 m g / L S O 4 2

~ 2

59 Co C a l c i u m 43 Ca 16 O +
, 42 Ca 16 OH + 250 m g / L C a <MD L

60 Ni Silico n as SiO 2 28 Si 16 O 2 + 40 m g / L S i O 2 ~ 0

. 2

60 Ni C a l c i u m 44 Ca 16 O + 250 m g / L C a <MD L

63 Cu S odi u m 40 Ar 23 Na + 500 m g / L N a ~10

65 Cu T i t a ni um 49 Ti 16 O + 1 m g /L T i ~0.5

65 Cu Su lf ate 33 S 16 O 2 +

, 32, 33 S 2 + 1,000 m g / L S O 4 2

~ 2 0

66 Zn Ba ri u m 132 Ba 2+ 100 m g / L Ba ~5

66 Zn Chr o m i um 50 Cr 16 O + 1 m g /L C r ~0.1

66 Zn Su lf ate 34 S 16 O 2 +

, 32, 34 S 2 +

, 33 S 2 + 1,000 m g / L S O 4 2

~ 1 0

66 Zn T i t a ni um 50 Ti 16 O + 1 m g /L T i ~0.3

66 Zn V a na d i um 50 V 16 O + 1 m g /L V ~0.1

67

Zn Ba ri u m 134 Ba 2+

, 135 Ba 2+ 100 m g / L Ba >50

82 S e S u l f a t e 34 S 16 O 3 + 1,000 m g / L S O 4 2

~ 9
107 Ag Zi r c o n i u m 91 Zr 16 O + 1 m g / L Z r ~1

109

Ag N i obi u m 93 Nb 16 O + n o t d e term in ed n o t d e term in ed

111 C d M o l y bden u m 95 Mo 16 O + 1 m g /L Mo ~0.4

114 Cd Mol y bden u m 98 Mo 16 O + 1 m g /L Mo ~0.6

1 Is otopes th at are rou tin ely u s ed as s econ d ary is otopes are lis ted in italic.



### Errors rang ed from 0.5 to 1  g / L copper or

z i nc for sulfate concentrations from 0 to 1,000 mg /L

.
An alternative correction method de te r mine s the line a r reg r ession equations for apparent 65 

### Cu + 

### and 66 

### Zn + 

### as a function of sul f at e concent r at i on by anal y z i n g t w o sulfate standards (see sections 5B .21 and 22) wi t h each bat c h of sam p l e s. Aft e r t h e anal y s es have been com p l e t e d, t h ese equations and the sulfate concentrations obtained for each sample by using another analy tical method are used to determine the fraction of 65 

### Cu and 66 

### Z n concentrations that

r e sult f r o m sulf a t e

. The r e g r e ssion equations and interference corrections are calculated by using a software prog ram that i s ex ecut e d fol l o wi ng t h e anal y s es. The
accuracy of this method of interference correction is equiva lent to the method described in the preceding parag r aph, however, i t i s l i k el y t o be m o re accurat e as cal ci um concent r at i ons i n crease.

AN AL Y T I C AL M E T H O D S 16

### Ox ides of chromium, moly bdenum, niobium, silicon, titanium, vanadium, and

z i rconi um g e neral l y are neg l i g i b l e because of the low a m bie n t c onc e n tr a tion le ve ls f o r

the s e el em ent s i n whol e-wat e r di g e st s. I n t e rferences

on 111 

### Cd + 

### (from 95 

### Mo 16 

### O + 

### ) and 66 

### Zn + 

### (from
50 

### Cr 16 

### O + 

### ) are not rout i n el y det e rm i n ed because the inte r f e r e nc e s a r e ne g lig ible a t moly bde num and chromium concentrations that are usually present in natural whole-water dig e sts. Comparing results for primary and secondary isotopes may identify other possible ox ide i n t e rferences. For ex am pl e, com p ari n g 107 

### Ag +



### to 109 

### Ag + 

### results could indicate the deg r ee of

z i rconium or niobium interference on silver.

I f

concentration leve ls of interferentcausi ng el em ent s ex ceed t hose l i s t e d i n tables 5 and 6, the samp le must be dilute d by an appropriate fact or and reanaly z ed. Dilution must be ma de by using the c a libr a tion blank (see section 5B .3).

3B .2.3 Doubly charged ion interferences: A doubly charg e d ion is created in the plasma for
any element that has a second ioniz a tion pote n tia l tha t is le ss tha n the ioniza tion pote n tia l for arg on. Under norma l operating conditions, the I C P–MS g e nerates less than 0.2 percent doubly charg e d barium ion (see table 6). Apparent copper and zinc concentrations will

ex ceed MDL concent r at i on l e vel s whenever barium concentrations ex ceed 1,000  g/ L

. L u tetium and y tterbium (176 amu) doubly

c h a r g e d ions will inte r f e r e with str ontium. Simila r l y , dy spr o sium, e u r opium, a nd holmium (163, 164, and 165 amu) doubly charg e d ions inte r f e r e with se le nium. The s e r a r e e a r th isotopes, however, are usua lly found at neg lig ible concentrations in whole-water dig e sts.

T a b l e 6. Doubly c har ged ion inter f er enc es f o r elem ents deter m i ned in w hole- w a ter diges ts by ICP–MS

[IC P

– MS, in du ctiv ely cou p led plas m a –m as s s p ectrom e try ;  g / L
, m i cro g ram p e r liter; m g /L , m illig ram p e r liter;
~, approx i m at e]

Is otope In t e rf eren t In t e rf eren t ion In t e rf eren t

co n cen t r at io n A p p a ren t elemen t

co n cen t r at io n ( μ g/L)

65 C u B a r i um 130 Ba 2+ 1 m g /L Ba ~0.1
66 Z n B a r i um 132 Ba 2+ 1 m g /L Ba ~0.4
67 Z n B a r i um 134 Ba 2+ 1 m g / L Ba ~10



### 4B. A pparat u s, I n st rument at i on, and O p erat i ng Condi t i ons



### 4B .1 Labware: See section 4A.1

4B .2 Instrumentation: VG El em ent a l PlasmaQuad I I C P–MS sy stem, which consists of a Gilson 222 automatic sampler, hig h -solids
pne uma tic ne bulize r , Gilson pe r i sta ltic pump, internal standard in troduction manifold, computer sy stem, and printer. The hig h -solids nebuliz er used for sa mple introduction was a
pa r a lle l- pa th de sig n tha t wa s e n tir e l y constructed of tetraf luoroethy l ene monomer (CPI I n c., Model 50, P/N 4060-69). This nebuliz er desig n resists clog g i ng and is

c h e mic a lly ine r t. Othe r nebuliz er desig n s can be used, however, they must be resistant to clog g i ng and capable of providing MDL s that are within a factor of two of those listed in

AN AL Y T I C AL M E T H O D S 17

### table 1. More state-of-the-art (circa 1997) I C P– MS instr u me nts will pr ovide MDL s tha t a r e a factor of 4–50 times lower than levels reported in this study . I n strument software must be capable of providing a u toma tic inte r f e r e nc e correct i on (for ex am pl e, PQVision Version 4.1.2).

4B .3 Operating conditions:

 Isotopes—

I s otopes used to quantify elements, whic h a r e de te r mine d in whole-water dig e sts by inductively coupled plasma–mass spectrometry
, are listed in table 7. Secondary isotopes are in italic. I n addition, the use of the sum of all four le a d isotope s f o r

qua ntita tion is hig h ly

recom m e nded because t h e l ead i s ot opi c abundance in a sample ma y deviate from natural abundance.

 Internal standards—

45 

### Sc
, 115 

### I n, and 208 

### Bi are used as i n t e rnal standards in the interpolated mode. Other inte r f e r e nc e

- f r e e isotope s ma y be substitute d if needed.

 Inductively coupled plasma—

I n cident radio frequency power: ~ 1.3 k W Reflected radio frequency power < 5 W Coolant flow rate ~ 13 L/m i n A uxiliary flow rate ~ 0.5 L/m i n Nebuliz er flow rate ~ 0.7 L/m i n



###  Va c uum sy ste m , in milliba r —

Sect io n Static p r essu re O p erat in g p r essu re
A n aly zer ~ 1 X 10 -8 ~ 5 X 10 -6
In term ed i a t e ~ 1 0 -4

~ 10 -4
E x p a nsi o n a t m o sp he r e ~ 1

. 5



###  Ion sampling position— Sig n al response on the rate meter for 115 

### In i s

ma x imize d while a d justing the x , y , a nd z positioning on the torch box

.

T a b l e 7. Is otopes us ed to quantif y

elem ents deter m i ned in w hole- w a ter diges ts by ICP–MS

[IC P

– MS, in du ctiv ely cou p led plas m a –m as s s p ectrom e try ]

E l e m e n t I s otope 1 E l e m e n t Is otope 1 E l e m e n t Is otope 1

A l u m i n u m 2 7 C o p p e r 6 5
, 63 S i l v e r 1 0 7
, 109
A n t i m on y 1 2 1 L e a d 2 2 0 8 S t ron t i u m 8 8
B a riu m 1 3 7 L ith iu m 7 T h alliu m 2 0 3
B e ry lliu m 9 Man g a n e s e 5 5 Uran iu m 2 3 8
C a dm i u m 1 1 1
, 114 M o l y bden u m 9 5 Z i n c 6 6
, 67
Chr o m i um 3 5 2 N i ck el 6 0
C obal t 5 9 S e l e n i u m 8 2

1 Seco n d ary iso t o p e s are sh o w n

in italic.
2 T h e s u m of all lead is otopes (204, 206, 207, an d 208) f o r qu an titation is h i g h l y recom m e n d ed (s ee s ection 4B .3).
3 Qu an tif ication can be problem atic becau s e of m o lecu lar ion in terf eren ces

.

AN AL Y T I C AL M E T H O D S 18

###  Ion optics—

The pote n tia ls a pplie d to the ion optic s

a r e optimize d to g i ve the ma x imum r e a d ing on the r a te me te r f

o r 115 

### I n. Nominal vernier setting s for each ion lens are listed below.

Le ns Vern ier

s e tting Le ns Vern ier

s e tting
C o l l ect or ~ 8 L 4 ~ 2 Ex tractio n ~ 0

. 5 Dif f e ren t i a l apertu re ~ 1

L 1 ~ 8 F r on t pl at e ~ 5 L 2 ~ 6 Pol e bi as ~ 5 L 3 ~ 5 P r ef ilter ~ 4



###  Pe ristaltic pump—
Pump r a te is a d juste d to a ppr ox ima te ly 1 mL /min.

 Internal standard manifold—

The internal standard introduction
sy stem uses a 12-turn microbore mix ing coil (Alpkem 303-0310), microbore double injection fitting (Alpkem 303-107-00), microbore debubbler (Alpkem 303-0103-00),

a nd the pe r i sta ltic pump tubing tha t is liste d in fig u re 1b (see Appendix )

.

 Detector potential—

The pote n tia l a pplie d to the e l e c t r on multiplie r must be optimize d by using

ma nuf a c t ur e r ’ s g u ide line s ( G a lile o Ele c t r o

Optic Corporation, 1991). This potential will inc r e a s e ove r the lif e of the multiplie r

.

 Data acquisition—

Dat a are acqui red usi n g t h e peakhopping mode to collect three points per peak per isotope. Three 40-second integ r ations are
averag ed for t h e report e d resul t

.  Mass calibration and resolution—

Mass calibration is verified at 4 to 6 masses that ex tend throug hout the full mass
rang e. The calibration must be within 0.1 amu of t h e t h eoret i cal val u e for each m a ss.
The valley s between Mg and Pb isotopes must be about 10 percent of the max imum peak heig ht.

 Oxide molecular ion and doubly charged i on l evel s—

Ox ide and doubly charg e d ion intensities should be less than the following upper limits:

BaO + 

### / B a + 

### < 0.5 percent Ba 2+ 

### / B a + 

### < 3 percent

 Aut o sampl e r cycl es—

Autosa mple r c y c l e time s liste d be low minimiz e carry over in the sample introduction config uration shown in fig u re 1b (see Appendix )

. Rinse cy cle ~ 60 seconds F l ush cy cle ~ 75 seconds

5B. Reagent s and Cal i b rat i on St andards



### AS TM Ty pe I reag ent wat e r (Am e ri can Society for Testing and Materials, 1995, p. 122–124), spectroscopic g r ade commercial standards, and ultrapure acids must be used to
pr e p a r e a ll solutions. All pe r c e n ta g e s represent volume-to-volume ratios. All
concent r at ed aci ds and com m e rci a l st andards must be verified to c ontain concentrations of

c onc omita nt e l e m e n ts tha t a r e le ss tha n the MDL s after the prescribed dilution. Every solution must be stored in a desig n ated clean F E P Te f l on bottle ; solutions tha t c onta i n silve r must be stored in a desig n ated clean opaque F E P Te f l on bottle

.

AN AL Y T I C AL M E T H O D S 19AN AL Y T I C AL M E T H O D S 20 

### 5B.1 Nitric acid (HNO 3 

### ): Concentrated, specific gravity 1.41.

5B.2 Hydrochloric acid (HCl): Concentrated, specific gravity 1.196.

5B.3 Calibration blank : Reagent water acidified to 0.4 percent nitric acid and 2 percent hydrochloric acid.

5B.4 Commercial single-element standard solutions , 1.00 mL = 10 mg preserved in nitric acid for each of the following: Al, Ag, Ba, Bi, Be, Cd, Co, Cr, Cu, In, Li, Mn, Mo, Ni, Pb, Se, Sb, Sc, Sn (may include a low percen tage of hydrofluoric acid), Sr, Tl, U, and Zn.

5B.5 Commercial sulfate standard , 1.00 mL = 10 mg sulfate in water (from sodium sulfate).

5B.6 Multielement stock solution I , 1.00 mL = 0.010 mg of Be, Cd, Co, Cr, Cu, Mo, Ni, and Pb: Dilute 1.0 mL of each commercial sing le-element standard to 1,000 mL in a volumetric flask with 1 percent nitric acid.

5B.7 Multielement stock solution II
, 1.00 mL = 0.010 mg of Se, Sb, Sr, Tl, and U: Dilute 1.0 mL of each commercial singleelement standard to 1,000 mL in a volumetric flask with 1 percent nitric acid.

5B.8 Multielement stock solution III
, 1.00 mL = 0.010 mg of Al, Ba, Mn, and Zn: Dilute 1.0 mL of each commercial singleelement standard to 1,000 mL in a volumetric flask with 1 percent nitric acid.

5B.9 Lithium stock solution IV , 1.00 mL =0.010 mg of Li: Dilute 1.0 mL lithium commercial sing le-element standard to 1,000 mL in a volumetric flask with 1 percent nitric acid. 5B.10 Silver stock solution V , 1.00 mL = 0.010 mg of Ag: Dilute 1.0 mL silver commercial sing le-element standard to 1,000 mL in a volumetric flask with 1 percent nitric acid.

5B.11 Multielement calibration standard I, 1.00 mL = 0.025  g Al, Ag, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Se, Sb, Sr, Tl, U, and Zn: Dilute 0.250 mL of multielement stock solutions I, II, and III, lithium stock solution IV and silver stock solution V to 100 mL in a volumetric flask with calibration blank.

5B.12 Multielement calibration standard II, 1.00 mL = 0.100  g Al, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Se, Sb, Sr, Tl, U, and Zn: Dilute 1.0 mL of multielement stock solutions I, II, and III and lithium stock solution IV to 100 mL in a volumetric flask with calibration blank.

5B.13 Multielement calibration standard III
, 1.00 mL = 0.500  g Be, Cd, Co, Cr, Cu, Li, Mo, Ni, Pb, Se, Sb, Sr, Tl, and U: Dilute 5.0 mL of multiele ment stock solutions I, II, and III and lithium stock solution IV to 100 mL in a volumetric flask with calibration blank.

5B.14 Multielement calibration standard IV, 1.00 mL = 1.00  g Al, Ba, Mn, and Zn: Dilute 1.0 mL of multielement stock solution III to 100 mL in a volumetric flask with calibration blank.

5B.15 Internal standard stock solution
, 1 mL = 0.1 mg Sc, In, and Bi: Dilute about 10 mL of each commercial single-element standard for Sc, In, and Bi and 10 mL ultrapure nitric acid to 1,000 mL in a volumetric flask with reagent water.

### 5B .16 Brij- 35 (CAS 9002-92-0), 30 percent solution of pol y o x y ethy lene laury l ether.

5B .17 Internal standard working solution , 1 mL = 0.5  g Sc, I n, and B i: Dilute 5 mL of internal sta ndard stock solution and 100  L of B r ij-35 solution to 1,000 mL in a volumetric flask with calibration blank.

5B .18 Performance check standard
, 1.00 mL = 0.010  g of Ag , Al, B a , B e , Cd, Cr, Co, Cu, L i , Mn, Mo, Ni, Pb, Sb, Se, Sr, Tl, U, and Z n. Dilute 4.0 mL of multielement calibration standard I to 10 mL with calibration blank.

5B .19 Int e rf erence check st ock sol u t i o n , 1.00 mL = 0.010 mg Sn: Dilute 1.0 mL of the tin c o mme r c ia l sing le

- e le me nt sta nda r d to 1,000 mL in a volumetric flask with 1 percent nitr ic a c i d.

5B .20 Interference check standard , 1.00 mL = 0.100  g of Sn. Dilute 1.0 mL of interference check stock solution to 100 mL in a volumetric flask w ith calibration blank.

5B .21 Sulfate inte rfe r e n c e c a libration standard I , 1 mL = 100  g of sulf a t e

. Dilute 0.1 mL of sulfate standard to 10 mL with calibration blank.

5B .22 Sulfate inte rfe r e n c e c a libration standard II , 1 mL = 500  g of sulf a t e

. Dilute 0.5 mL of sulfate standard to 10 mL with calibration blank.

5B .23 Tuning solution , 1 mL = 0.1  g B e , Co, I n, Mg , Pb, U: Dilute about 10  L of each com m e rci a l si ng l e -el e m e nt st andard for B e , Co, I n, Mg , Pb, and U and 10 mL reag ent g r ade nitric acid to 1,000 mL in a volumetric fl ask wi t h reag ent wat e r. 6B. A n al y t i cal Procedure



### Refer to VG Elemental (1988, 1994) and NW QL Standard Operating Procedure I M 0011.0 (J .R. Garbarino and M.R. Hill, U.S. Geolog ical Survey , written commun., 1994) f o r

de ta ils of pr oc e dur e s outline d in the following parag r aphs.

6B .1. I g nite plasma. Ensure that inductively coupled plasma and vacuum conditions are set correctly (see section 4B .3). Allow a t le a s t 30 minute s pr ior to optimiz ation. Use the tuning solution (see section 5B .23) for procedures outlined in sections 6B .2–4.

6B .2. Optimiz e plasma-sampling position and ion optics.

6B .3. Adjust the electron multiplier voltag e to provide about 2,000 counts per second for 1  g/ L 115 

### I n.

6B .4. Verify mass resolution and mass calibration.

6B .5. Assemble an analy tical procedure having the calibrati on blank, multielement calibration standards, QA/QC samples, and unknown samples. I n addition, include sulfate inte r f e r e nc e c a libr a tion solutions if e x te r n a l calibration is being used.

6B .6 L o a d the a u tosa mple r with calibration blank, multie lement calibration standards, QA/QC samples, and unknown

sam p l e s. Ex ecut e t h e anal y t i cal procedure.

6B.7 Veri fy t h e accuracy of t h e

c a libr a tion using the r e sults f r o m the performance check solution. Concentrations must not de via t e f r o m the the o r e tic a l concentrations by more than ±5 percent (ex cept for selenium at ±30 percent). Ele m e n ta l r e la tive sta nda r d de via tions f o r

the performance check solution must be within

AN AL Y T I C AL M E T H O D S 21

### ±0.5 percent of the variability listed in table 17 for 12.5  g / L

. The instrument must be rec a libr a te d f o r

f

a ilur e in e ithe r c r ite r i on f o r

a n y el em ent

.
6B.8 Veri fy t h e accuracy of i n t e rference correction equations by analy z ing the i n t e rference check st andard (see sect i on 5B .20). I f either the indium intensity ex ceeds that of the calibration blank by more than 5 percent, or the secondary cadmium isotope ( 114 

### C d ) concent r at i on ex ceeds t h e MDL
, t h en the instr u me nt must be r e c a libr a te d or the interference equations mu st be reestablished before continuing sample analy s es.

6B .9 The QA/QC plan requires analy s is of at least one of the following at a frequency of at least 1 in every 10 unknown samples: SRW S , calibration blank, duplicate sample, dilute d sa mple , or ma tr ix spike

. I f SRWSs a r e

use d, the a n a l y s t must e n sur e tha t r e sults f a ll within the e s ta blishe d qua lity

- c ontr o l limits. Selection of a suitable SRW S should be based
on t h e ex pect ed sam p l e concent r at i on rang e.

6B .10 Acceptance criteria for duplicates, dilutions, and matrix spikes are f u lly outline d in the SOP. I f a ll da ta

accept a nce cri t e ri a are m e t , t h en t h e anal y t i cal resul t s are accept a bl e. I f any one cri t e ri on i s not sat i s fi ed, t h en t h e anal y s t m u st reanal y z e the sample in question. I f the results remain outside the criteria, the instrument must be

r e c a libr a te d a nd a ll sa mple s f o llowing the la st accept a bl e QA/ QC check reanal y z ed. The upper calibration limits do not represent the endpoint of the linear analy tical rang e but

r a the r a

c onc e n tr a tion limit mor e a ppr opr ia te f o r

the ma jor ity of sa mple s a n a l y z e d. Ne ve r t he le ss, if a n e l e m e n ta l r e sult is g r e a t e r than the upper calibration limit, the sample must be dilute d ( w ith the c a libr a tion bla nk)

a nd r e a n a l y z e d so tha t the c onc e n tr a tion will be less than the upper calibration limit. 7 B . C a lc u l a t io n s


### Correct the copper and z i nc results from sul f at e i n t e rference aft e r t h e anal y s es have be e n c o mple te d if e x te r n a l sulf a t e c a libr a tion was used. This operation can easily be done by using a spreadsheet prog ram. All other cal cul a t i ons are perform ed aut o m a t i cal l y by the ope r a ting sy ste m . I f a

sa mple wa s dilute d, the a ppr opr ia te diluti on factor must be i n cl uded i n t h e anal y t i cal procedure before t h e

a

u toma tic c a l c u la tion is performed. L i near reg r essi on coeffi ci ent s and standard and

sam p l e concent r at i ons for every el em ent are pr inte d out imme dia t e l y a f te r the a n a l y s e s

. VG Elemental (1994) describes the formulas
t h at are used i n t h e cal cul a t i ons.

8B. Report i ng of Resul t s


### The number of sig n ificant fig u res

r e por te d in the r e sults va r i e s with e l e m e n t a nd is a function of concentration. W h enever the

c onc e n tr a tion is le ss tha n the MDL f o r

a n

e l e m e n t, the r e sult is r e por te d a s le ss tha n the MDL ( < MDL ) . All othe r e l e m e n ta l r e sults for whole-water dig e sts are reported by using the c r ite r i a liste d be low. The s e c r ite r i a a r e based on the uncertainty indicated in table 17. Alte r n a tive l y , the va r i a b ility tha t is a ssoc i a t e d with the me a n c onc e n tr a tion ( r e por te d with the

m ean by each i n st rum e nt ) m easured i n each sample could be used to e s ta blish the a ppr opriate number of sig n ifi cant fi g u res t o report

. The use of such a procedure would provide the most accurate estimate of the uncertainty that i s associ at ed wi t h each uni que sam p l e m a t r i x

. For antimony , barium, be ry llium, cadmium, copper, lithium, manganese, molybdenum, nickel, and zinc—

AN AL Y T I C AL M E T H O D S 22

###  I f t h e concent r at i on i s g r eat er t h an or equal to the MDL
, but less than 100  g/ L
, then report result to the nearest 0.1  g/ L

.

 I f t h e concent r at i on i s g r eat er t h an 100  g / L
, but less than 500  g / L
, then report

r e sult to the ne a r e s t 1  g/ L

.

 I f t h e concent r at i on i s g r eat er t h an 500  g / L
, the n r e por t r e sult to the ne a r e s t 10
 g/ L

. For cobalt, lead, silver, strontium, thallium, and uranium—

 I f t h e concent r at i on i s g r eat er t h an or equal to the MDL
, but less than 10  g/ L
, then report result to the nearest 0.01  g/ L

.

 I f t h e concent r at i on i s g r eat er t h an 100  g / L
, but less than 500  g / L
, then report

r e sult to the ne a r e s t 1  g/ L

.

 I f t h e concent r at i on i s g r eat er t h an 500  g / L
, the n r e por t r e sult to the ne a r e s t 10
 g/ L

. For aluminum, chromium, and selenium—

 I f t h e concent r at i on i s g r eat er t h an or equal to the MDL
, but less than 500  g/ L
, the n r e por t r e sult to the ne a r e s t 1  g/ L

.

 I f t h e concent r at i on i s g r eat er t h an 500  g / L
, the n r e por t r e sult to the ne a r e s t 10
 g/ L

.

DISCUSSION OF RESULTS

A ccuracy and Variabilit y
The accuracy and variability for the anal y s i s of whol e-wat e r di g e st s are eval uat e d by comparing results obtained by I C P–OES and I C P–MS to results obtained by former USGS methods of analy s is. Results from the analy s is of dig e sted SRW S , spiked natural whole-water dig e sts, and 43 natural wholewat e r di g e st s are used t o i d ent i f y

el em ent s t h at can be determined by using I C P–OES or I C P– MS , whi l e m a i n t a i n i n g or ex ceedi n g t h e performance of the form er methods. F o rmer USGS methods include U.S. Geolog ical Survey approved methods (F ishman and F r iedman, 1989; F i shman, 1993) and U.S. Environmental Protection Ag ency methods of analy s is (U.S. Environmental Protection Ag ency , 1992) that have been adapted for use
at t h e NW QL

.

I t is either not practi c a l or instr u me nta lly impossible to determine all elements by both I C P–OES and I C P–MS. Antimony is not det e rm i n ed by I C P

– OES because t h e instrument currently (1998) does not support it, a nd the de te r mina ti on of selenium is not feasible because of poor sensitivity . Calcium, iron, mag n esium, silicon, sodium, and vanadium are not determined by I C P–MS ei t h er because t h e concent r at i on l e vel normally present in whole-water dig e sts

ex ceeds t h e worki n g rang e of t h e t echni que or because subst a nt i a l m o l ecul a r i on i n t e rferences are present

.

Resu lt s f o r Dig est ed St an d a rd Ref e ren ce W a t e r Samp les


### U.S. Geolog ical Survey SRW S T107, T119, T133, T135, and W W -1 were analy z ed to determine the accuracy and variability of the I C P–OES and I C P–MS methods. Only W W

- 1 approx imates a na tur a l whole

- wa te r sample that has suspe nded sediment, althoug h the amount of sediment ex ceeds the level
rout i n el y present i n such sam p l e s t h at are submitte d to the NWQL . Othe r SRWSs a r e f ilte r e d, a c i dif i e d na tur a l- wa te r ma tr ic e s

. SRW S T135 was only analy z ed by I C P–OES because sel ect ed el em ent s are present at

c onc e n tr a tions be tte r suite d to e v a l ua te the

DISCUSSION OF RESULTS 23

### accuracy for less sensitive elements (for

e x a m ple
, le a d a nd moly bde num)

. Te n bottle s of SRW S T107, T119, T133, and T135 and f i ve bottle s of WW- 1 we r e dig e ste d on dif f e r e nt da y s by using the in- bottle dig e stion procedure (Hoffman and others, 1996).

I n g e neral
, resul t s for S R W S di g e st s from I C P–OES and I C P–MS were obtained within dif f e r e nt time doma i ns. Da ta f

o r SRW S T107, T119, T133, and T135 by I C P– OES represent short-term (about 1-hour) resul t s obt ai ned by anal y z i n g each of 10 i n

bottle SRWS dig e sts within a sing le calibration period. I n c ontrast, all the SRW S data from I C P–MS correspond to long -term results obtained by analy z ing all the standard solutions over a 2-week period using different cal i b rat i ons. However, l ong -t erm accuracy and variability of the tw o methods are directly

c o mpa r a b le using r e sults f r o m SRWS WW- 1. All f i ve bottle s of SRWS WW- 1 we r e analy z ed four times over a 2-week period.

The a n a l y tic a l va r i a b ility of the two techniques is compared by using the variance f r o m de te r mina tions of standards that have a wide rang e of concentrations. Three de te r mina tions we r e performed sequentially on a sing le aliquot in less than 1 minute. A W W

- 1 dig e st, or another SRW S that has more suita ble c onc e n tr a tion le ve ls f o r

I C P–OES, and a seri es of st andards are used for com

paring the data.

The accuracy of t h e S R W S resul t s i s

ex am i n ed by com p ari n g t h e ex peri m e nt al mean to the published most probable value (MPV) by use of two methods. F i rst, the

ex peri m e nt al m ean i s com p ared t o t h e 1  (68 percent) confidence interval about the published MPV. Then the Student t -Test or the W ilcox on Sig n ed Rank Test, depending on whe t he r the da ta se t wa s normally distributed and showed equal variance, is used to test whet her t h e ex peri m e nt al m ean i s si g n i f i cant l y different from the MPV at the 95-percent confidence level (a p- value less than 0.05). F r equently the p-value indicates that the

ex peri m e nt al m ean i s sig n if ic a n tly dif f e r e nt from the MPV, even thoug h the result is within the c onf ide n c e inte r v a l of the MPV. I n most of the s e c a s e s , f a ilur e is r e la te d to the

va r i a b ility in the e x pe r ime nta l da ta , a nd the di fference bet w een t h e ex perimental mean and the MPV is a n a l y tic a lly insig n if ic a n t.

S hort

- t e rm I C P

– OES resul t s for S R W S T107, T119, T133, and T135 are listed in tables 8 throug h 11. The confidence intervals about the MPV and the ex perimental I C P– OES mean are shown in fig u res 5a, 6a, and 7a and in fig u re 8 (see Appendix ) . The ex perim e nt al m eans for el em ent s det e rm i n ed by I C P–OES were inside the 1  -confi d ence inte r v a l of the MPV f o r

a ll SRWS e x c e p t f o r cal ci um , m a g n esi u m , m a ng anese, ni ckel
, silver, vanadium, a nd z i nc. Calcium,
mag n esium, mang anese, and vanadium means, however, are wi t h i n t h e 1.5  -confidence i n t e rval t h at i s accept a bl e by t h e NW QL

. Silve r is only slig htly outside the inte r v a l in S R W S T135. All z i nc data are acceptable

ex cept for T133, which is neg a tively biased. Nickel results are outside the 1  -confidence interval in 75 percent of the SRW S s and
g r eat er t h an 1.5  for T107 and T119.

All long

- t e r m e x pe r ime nta l me a n s f o r SRW S T107, T119, and T133 by I C P–MS (see tables 12 throug h 14 and fig u res 5a, 6b, and 7b in Appendix ) are within the 1 

- confi d ence i n t e rval of t h e MP V ex cept for bery llium, boron, chromium, lithium, and silve r . The me a n be r y llium a nd lithium concentrations measured in T107 are outside the 1.5  -confi d ence i n t e rval of t h e MP V. B o ron and chromium results for T107 and silver in T119 are inside the 1.5  -confi d ence i n t e rval for t h e MP V.

DISCUSSION OF RESULTS 24DISCUSSION OF RESULTS 25 

### The 1  -confidence interval about the MPV, the long-term ex perimental mean and standard deviation, the st atistical test used, the test statistic value, and the p-value for SRWS WW-1 are listed in table 15. The MPV confidence interval and the experimental results from ICP–OES and ICP–MS are shown in figure 9 (see Appendix). Elemental results from both methods are within the 1 

- confidence interval of the MPV except for ICP–OES cadmium and nickel results; however, both elements are well within the 1.5  -confidence interval, so the data are acceptable. For selected elements, one method can be seen to have greater long-term accuracy and variability than the other. For example, the experimental mean for beryllium, cadmium, and nickel by ICP–MS are somewhat more accurate than for ICP– OES; results for the other elements are equivalent. Less variability is indicated in the ICP–OES data for some of the lighter elements (those less than 60 amu, for example, beryllium, chromium, lithium, and manganese). Increase in variability for someof the ICP–MS results may be the consequence of shifting spectral background that is not entirely offset by the internal standard. Cadmium, molybdenum, nickel, and silver concentrations are at or less than the ICP–OES MDLs and the aluminum concentration is much greater than the 1,000- μ g/L calibration limit for ICP–MS.

The analytical variability in ICP–OES and ICP–MS data from WW-1 (except for aluminum, cobalt, lead, molybdenum, and silver which used othe r reference standards) is listed in table 16. The analytical variability should represent only the component associated with each method because using a single WW-1 digest eliminates the variability from the in-bottle digestion procedure and the homogeneity of WW-1. SRWS T107 data were used for aluminum (220 μg/L), cobalt (11 μg/L), and silver (12 μg/L) and SRWS T117 was spiked with about 100 μg/L lead and 50 μg/L molybdenum to pr ovide concentration levels measurable by ICP–OES. The median analytical variability for elements common to both methods is about a factor of two to three better by ICP–MS. The variability in elemental results is lower for ICP–MS than for ICP–OES when concentrations are less than 100  g/L, a decrease most likely a consequence of its higher sensitivity. In contrast, ICP–OES provides lower variability in elemental results for concentrations greater than 100
 g/L (for example, barium, manganese, and strontium). The analytical variability that can beexpected over an extended range of concentrations is listed in tabl e 17. In contrast to the variability presented for WW-1, these data were obtained for a calibrati on blank matrix and therefore correspond to optimal matrix conditions. The variability (in terms of percent relative standard deviation) generally increases as the concentration approaches the MDL. Elements with similar MDLs for ICP–OES and ICP–MS show about the same variability. Results for ICP–MS show much lower variability for elements, such as chromium, cobalt, lead, molybdenum, nickel, and zinc, because the corresponding MDLs are lower. Nevertheless, the variability of both methods approaches each other as the concentrations increase. As with the WW-1 data, these data indicate that the variability of ICP–OES is somewhat lower for selected elements at higher concentrations (for example, barium and strontium in table 17).

Spike Recoveries in Natural Whole-Water Digests


### The percentage of spike recoveries for allelements was determined in six natural wholewater digests. Two ground-water and four surface-water samples that have specific conductance that are representative of the rangeDISCUSSION OF RESULTS 26 

### of whole-water samples submitted to thelaboratory for analysis were spiked. The predigestion specific conductances for the groundwater samples were 519 and 1,600  S/cm and 103, 230, 683, and 1,900  S/cm for the surface-water samples. The spike concentration level was determined individually for each sample and element. First, the original concentration of every element was determined in each sample digest. If the original concentration was found to be less than the MDL, the concentration of the spike was ten times the MDL, otherwise the sample was spiked at two times the original concentration.Spike recovery results for the wholewater digest samples are listed in table 18. The average percent recovery for the six samples was used as an indicator for the overall accuracy of each method for every element. The average percent recovery is within 100  10 for all elements determined by ICP–OES. All elements determined by ICP–MS were also within this range except for beryllium, cadmium, chromium, manganese, and silver. The average percent recoveries for these elements are only marginally outside the 10- percent interval. Nevertheless, the recoveries are acceptable, considering that beryllium, cadmium, chromium, and silver were spiked at low concentrations. The mean recovery for manganese should have been expected to be within 10 percent, however, the mean recovery was influenced by the spike recovery for onedigest. Low spike recoveries in the groundwater sample that have high specific conductance indicate high concentrations of dissolved solids may affect the accuracy of ICP–MS determinations (see table 18, for example, boron, cobalt, copper, lithium, manganese, nickel, and zinc). For this particular sample, the pe rcentage recovery for selected elements was invariably low, however, never by more than 25 percent. Comparison of Inductively Coupled Plasma– Optical Emission Spectrometry and Inductively Coupled Plasma–PMass Spectrometry to Former Methods in the Analysis of Natural Whole-Water Digests


### Forty-three acidified, whole-water samples that had been digested by using the in-bottle procedure were selected from the population of such samples that were submitted to the NWQL. Selected digested whole-water samples ha ve a wide range of element concentrations and specificconductance. Both surface-water and groundwater samples are included in the sample set; the number of each type is approximately proportional to its fr action of the total submitted for analysis during an average year. Other chemical characteristics that often influence the performance of analytical methods, such as sulfate concentration, chloride concentrati on, and alkalinity, were also considered in the selection process (see table 19 for sample characteristics).

Every sample digest was analyzed by ICP–OES, ICP–MS, and one former method. The former method was either stabilized temperature graphite furnace–atomic absorption spectrophot ometry (GF–AAS), flame–atomic absorp tion spectrophotometry (F–AAS), or direct current plasma–atomic emission spectrometry (DCP–AES), depending on the elemen t being determined.

The presence or absence of significant bias (bias relative to the former method as opposed to method analytical bias) in ICP– OES and ICP–MS results was determined using a combination of statistical treatments. ICP–OES and ICP–MS results were compared to former method results by constructing

### scatterg rams and box plots to show the bias and variance of the data se t, by de te r mining l i n ear reg r essi on coeffi ci ent s t o i d ent i f y sy stematic errors, and by using statistical analy s is techniques to test whether I C P–OES and I C P–MS results differed sig n ificantly from former method results. B e fore an appropriate method of statistical analy s is could be selecte d, a ll da ta se ts we r e te ste d f

o r

nor ma lity a nd e qua l va r i a n c e

. I f the da ta se t was normally distributed with equal variance,

a

pa r a me tr ic te st wa s used, otherwise, a nonparametric te st was used.

A r e a listic sta tistic a l e v a l ua tion of the

sa mple r e sults wa s provided by only

com p ari n g resul t s t h at were g r eat er t h an t h e MDL s a nd within the c a libr a tion r a ng e of the methods being compared. The only ex ception to this approach was for comparisons made to GF –AAS. A hig h percentag e of whole-water dig e sts analy z ed by GF –AAS required dilution because of i t s narrow l i n ear cal i b rat i on rang e. I f

the s e sa mple s we r e omitte d, the da ta se t would have been too small for statistical analy s is. I n contrast, only a small number of dig e sts required dilution for the other methods. Statistical analy s is was impractical for som e el em ent s because t h e num ber of

sa mple s ha ving r e sults g r e a t e r tha n the MDL

was sm al l

. For ex am pl e, cadm i u m , cobal t , lead, and moly bdenum have only a small number of samples with concent r at i ons g r eat er t h an t h e MDL s for I C P

– OES
, t h erefore, onl y I C P–MS results could be compared with GF

– AAS results. Aluminum, calcium,
mag n esium, and sodium concentrations

ex ceed t h e cal i b rat i on rang e for som e sam p l e s and for some methods. Selected elements could not be determined by both I C P–OES and I C P–MS, hence, only one method was compared to the former method. Nonparametric test pr ocedures g e nerally were used to compare methods because all the el em ent concent r at i ons ex tended several or de r s of ma g n itude . The Kr uska l- Wa llis Te st was used whenever suffi ci ent sam p l e resul t s were available for all th ree methods. The test

wa s use d to de te r mine if the r e wa s a n y sig n if ic a n t dif f e r e nc e in the me dia n s f r o m each method at the 95-percent confidence le ve l. Te st r e sults inc l ude the te st sta tistic , pvalue, and mean rank for each method. The mean rank is useful for relating individual methods to one another; the closer the mean ranks are to each other the better the overall correspondence. I n all instances, the g r oup-1 mean rank corresponds to I C P–OES data,
g r oup-2 corresponds to the I C P–MS, and
g r oup-3 corresponds to the former method. For sel ect ed el em ent s , I C P

– OES and I C P

– MS al so are com p ared i ndi vi dual l y t o t h e form er method using the One-sample Sig n Test to de te r mine if the r e is a n y dif f e r e nc e be twe e n t h e m e di ans at t h e 95-percent confi d ence le ve l. The One

- sa mple Sig n Te st wa s a pplie d whenever one of the three methods was omitted because of its limited data set or whenever only two methods were available for comparison.

L i near reg r ession analy s is was used to cal cul a t e t h e sl ope and y -i nt ercept coeffi ci ent s of the equation describi ng the relation between I C P–OES or I C P–MS to the former method. The r e lia bility of suc h a tr e a tme nt wa s improved by alway s using the more precise, or equally precise, method as the independent variable (the x

- ax is variable). The reg r ession coefficients (the slope, la be le d with the f o r

m e r method’s acrony m and th e y

- intercept) and
t h ei r 95-percent confi d ence i n t e rval s are provided (for ex ample, see fig

. 10a in Appendix )

. The rang e of el em ent concent r at i ons composing the sample set is listed in table 19. The 25 th 

### pe r c e n tile , 50 th 

### pe r c e n tile ( m e d ia n)
, 75 th 

### pe r c e n tile , a nd ma x imum c onc e n tr a tion for every el em ent dem onst r at e t h e broad concentration rang e of th e sa mple se t. The

DISCUSSION OF RESULTS 27

### fraction of samples havi ng concentrations less tha n the MDL pr ovide s insig h t into the suitability of each method for the analy s is of a representative subset of the whole-water dig e sts submitte d to the NWQL . Re sults of the Kr uska l- Wa llis Te st a nd One

- sa mple Sig n Test for each element are listed in table 20. Scatterg rams, box plots, and reg r ession coeffi ci ent s for t h e sam e dat a set al so are pr ovide d to a u g m e n t the sta tistic a l r e sults ( s e e fig s .10 throug h 30 in Appendix ) . There are no U.S. Geolog ical Survey approved methods for the determination of silicon, thallium, uranium, and vanadi um in whole-water dig e sts, therefore, no comparisons could be made to I C P–OES and I C P–MS. The

c onc lusions dr a w n f r o m a ll sta tistic a l
t r eat m e nt s are sum m a ri z e d for each of t h e following elements. I llustrations showing

r e sults of the sta tistic a l tr e a tme nts a r e provided in the Appendix (see fig s . 10–30). (0.88  0.02, see fig

. 10a) indicates there is a slig ht neg a tive bias (about 10 percent) in the I C P–OES r e sults; the la r g e y

- inte r c e p t is

ne g lig ible a t the 95- pe r c e n t c onf ide n c e le ve l (62  108). No sy stematic errors are indicated by t h e reg r essi on coeffi ci ent s for I C P

– MS i n relation to DCP–AES (slope=1.04  0.02, y

intercept= –3.8  104).

A n timony


### Only nine sample results could be

com p ared because over 70 percent of t h e

sa mple s ha d a n timony c onc e n tr a tions le ss tha n the MDL

. Antimony c onc e n tr a tion in the sample data set rang ed from about 0.8 to 5
 g / L

. Sinc e the limite d da ta se t wa s nor ma lly distributed with equal variance, the Student t

Te st wa s use d to de te r mine if the r e wa s a si g n i f i cant di fference bet w een t h e m eans from I C P–MS and GF –AAS. A p-value of 0.3061
sug g e st s t h at any di fference bet w een t h e

me a n s is sta tistic a lly insig n if ic a n t, howe v e r , the scatterg ram and box plots indicate considerable variation in the results and show
t h at I C P

– MS resul t s are neg a t i v el y bi ased by about 30 percent (see fig

. 11). A l uminum



### Se ve nte e n sa mple r e sults we r e omitte d f r o m the da ta se t use d in the sta tistic a l a n a l y s is because the upper calibration limit for aluminum by DCP–AES is 10,000  g / L and by I C P–MS is 1,000  g / L ; I C P–O E S ha s a n upper limit of 500,000  g / L

. However, the data set included two samples having the aluminum concentrations g r eater than 1,000
 g / L that were diluted and analy z ed by I C P– MS. Only one sample was omitted because
t h e al um i num concent r at i on was l e ss t h an an MDL

. Using data having aluminum concentrations from 13 to g r eater than 13,000
 g / L
, the Kr uska l- Wa llis Te st indic a t e d tha t t h ere was no si g n i f i cant di fference am ong results obtained using DCP–AES (the former method), I C P–OES, and I C P–MS (for n=25, the p-value=0.9750, see fig

. 10b). Nevertheless, the mean rank for I C P–MS is

som e what cl oser t o t h e m ean rank for DC P

– AES than is I C P–OES. The slope of the

r e la tion of I C P–O E S to D C P–A E S Barium



### The size of the da ta se t use d in the c o mpa r ison of I C P–OES and I C P–MS to the former F

– AAS method was limited because of the hig h F

–AAS method reporting limit of 100  g/ L (no MDL has been esta blished); therefore, only 20 sa mple s we r e use d in the sta tistic a l anal y s i s . The scat t e rg ram s show t h at t h ere i s considerable nonlinearity between F

– AAS and I C P–OES results and between F

–AAS and I C P–MS results (see fig

. 12a). The box plots show a sig n if ic a n tly la r g e r va r i a b ility in the F

– AAS r e sults. Ne ve r t he le ss, the Kr uska l- Wa llis Test i ndi cat es t h at t h ere i s no si g n i f i cant di fference bet w een resul t s for t h e t h ree methods (p-value=0.3754). The mean ranks for I C P

– OES and I C P

– MS resul t s were

DISCUSSION OF RESULTS 28

### fig

. 14d). The slope of the reg r ession (2.0  0.7, see fig

. 14a) also indicates that I C P– MS results are about two times g r eater than DCP–AES results. This difference can easily be seen in the box plot (see fig

. 14d). However, the slope of 1.00  0.03 for I C P–OES i ndi cat es cl ose ag reem ent wi t h DC P

–AES (see fig

. 14c). I n addition, the averag e difference between DCP–AES and I C P–OES over the

e n tir e c onc e n tr a tion r a ng e of the sa mple s wa s approx imately 8  g / L
, a concent r at i on t h at i s less than the method reporting limit for DCP– AES

. nearly equal althoug h slig htly g r eater than F

–AAS, indic a ting tha t F

– AAS r e sults ma y be biased low (also shown in the box plots for I C P–OES and I C P–MS in fig

. 12b). A

com p ari s on of reg r essi on anal y s i s coeffi ci ent s for I C P–MS and I C P–OES results shows close
ag reement (see fig

. 12c showing a slope of 1.13  0.04).

Bery llium



### All the sa mple s ha ve be r y llium concentrations less than the F

– AAS MDL
, and onl y fi ve are g r eat er t h an t h e I C P

– OES MDL of 0.7  g / L

. I C P–OES and I C P–MS results f o r

the s e f i ve sa mple s we r e nor ma llydistr ibute d with simila r va r i a n c e , so the Stude nt
t -Test was used t o com p are t h e resul t s . The
t e st i ndi cat ed t h at t h ere i s no si g n i f i cant difference in the data (p-value=0.0974) and a slope of 1.0  0.1 indicated neg lig ible bias (see fig

. 13). Cadmium


### The accuracy of the I C P

– OES method coul d not be det e rm i n ed because onl y one sample out of 43 had a c a dmium c onc e n tr a tion
g r eater than its MDL of 6  g / L

. Sta tistic a l anal y s i s i ndi cat ed t h at t h ere i s no si g n i f i cant difference in results from I C P–MS and GF

– AAS (p-value=0.0522, n=27, see fig

. 15) for

sa mple s with c a d mium c onc e n tr a tions r a ng ing from less than 0.1 to 6  g / L

. Also, the slope (1.00  0.02) and y

- intercept (0.03  0.03) indicate there is no sig n ificant bias or method offset

. Bor on



### F i fteen data points (seven samples having boron concentrations less than the MDL s and eig h t samples having boron concentrations g r eater than the I C P–MS upper calibration limit of 100  g / L ) we r e omitte d so tha t the da ta se t woul d have boron concentrations that rang ed from 13 to 82  g/ L

. T h e scatterg rams, box plots, and reg r ession coeffi ci ent s i ndi cat e consi d erabl e di fferences

a m ong the D C P–A E S, I C P–O E S, a nd I C P– MS results, a finding also supported by the Kruskal-W a llis Test (p-value= 0.0021, see fig

. 14b). The mean rank for I C P–OES was about 30 percent l o wer t h an t h e DC P

–AES m ean rank; I C P–MS was about 20 percent hig h er. I n treating the methods se parately by using the One

- sa mple Sig n Te st, the r e is still a sig n ificant difference (p-value=0.0288, n=36, see fig

. 14c) between DCP–AES and I C P– OES results and between DCP–AES and I C P– MS results (p-value=0.0009, n=28, see Calcium



### Thir ty

- t wo sa mple s ha ve c a lc ium

c onc e n tr a tions le ss tha n the c a libr a tion limit (60 mg /L ) of the former method (F –AAS). Sta tistic a l a n a l y s is of the da ta se t using the One

- sa mple Sig n Te st indic a t e d a

substa ntia l difference between I C P–OES and F

– AAS results (p-value=<0.0001, see fig

. 16). This difference is based on the fact that 29 out of 32 I C P

– OES resul t s were g r eat er t h an F– AAS; the me dia n dif f e r e nc e f o r

the da ta se t is

a

ppr ox ima te ly 1 mg /L for samples having from 1 to 60 mg /L calcium. However, the slope coefficient of the reg r ession 1.03  0.03
sug g e sts that the bias between F

–AAS and

DISCUSSION OF RESULTS 29

### unsatisfactory when iron concentrations

ex ceed 2 m g / L . I C P

– MS and GF–AAS resul t s from 31 samples having cobalt concentrations
rang ing from 0.5 to 86  g / L showed si g n i f i cant di fferences (p-val ue =0.0033, see fig

. 18c). The slope of 0.87  0.04
sug g e sts about 14 percent neg a tive bias in the I C P–MS data, however, the median difference between the methods was only about 0.3  g/ L (fig

. 18b). W h en data from three samples having the larg est deviation from the former method are omitted, the bias in the I C P–MS data was reduced to about 3 percent. I C P–OES results is neg lig ible. The box plots (see fig

. 16) also support this conclusion.

Chromium



### Because t h e MDL s for I C P

– OES (4  g/ L ) and I C P–MS (2  g / L ) are g r eat er t h an GF– AAS, the da ta se t is r e duced to only 15 samples having between 6 to 160  g / L c h r o mium. Using this da ta se t, the Kr uska l- Wa llis te st showe d the r e is a hig h pr oba bility tha t GF

– AAS, I C P–OES, and I C P–MS results are statistically different (p-value=0.0078), an outcome supported by the box plots in fig u re 17b. W h en comparing the methods individua lly to GF –AAS, the One

- sa mple Sig n Te st i ndi cat ed si g n i f i cant di fferences bet w een I C P

– OES and GF –AAS (p-value=<0.0001, n=15, see fig

. 17c) and between I C P–MS and GF

– AAS (p-value=<0.0001, n=26, see fig

. 17d). I C P

– OES results were alway s less than GF– AAS (by a median of 13  g / L ) and I C P–MS resul t s were al way s g r eat er t h an GF–AAS (by a median of 3  g / L ) . The slope of the reg r ession equation for I C P–OES in relation to GF –AAS (0.52  0.05) also shows a 50 percent neg a tive bias in the I C P–OES results (fig

. 17a). However, the slope (1.04  0.05) for the
reg r ession of I C P–MS in relation to GF –AAS
sug g e sts no sig n ificant bias, althoug h there is
pe r h a p s a slig ht of f

s e t in the r e sults ( y -i nt ercept = 3  2). Coppe r


### Due to the relatively hig h copper concentrations, 28 sample s could be used to compare I C P–OES, I C P–MS, and GF –AAS methods; 15 samples we re omitted because copper concentrations we re less than the MDL by I C P–OES. Copper concentrations rang ed from 3 to 370  g / L

. S t at i s t i cal anal y s i s of t h e da ta se t using the Kr uska l- Wa llis Te st indic a t e d tha t the r e sults f r o m the thr e e methods were not sig n ificantly different (p-value=0.5285, see fig

. 19b). Scatterg rams in fig u re 19a show a pattern of nonlinearity in GF –AAS for cooper concentrations g r eater than 100  g / L that is possibly a result of dilution error. The I C P–OES mean rank of 38 is slig htly less than the former method probably because about half the sample
concent r at i ons were near t h e MDL (see fi g

. 19b). I n contrast, the mean rank for I C P–MS equals that of GF –AAS and there is no si g n i f i cant di fference i ndi cat ed by t h e Onesample Sig n Test (p-value=0.6440, n=42, see fig

. 19c) for the ex tended data set. Coba lt



### C obal t concent r at i ons were g r eat er t h an the relatively hig h I C P–OES MDL of 10  g/ L in only six samples. I C P–OES g a ve hig h

r e sults f o r

f

our of the s e sa mple s whe n c o mpared to GF –AAS (see fig

. 18a). This i n accuracy i s rel a t e d t o t h e di rect spect ral overlap from a nearby iron waveleng th; the four samples had iron c oncentrations rang ing from 2 t o 50 m g / L . The accuracy of t h e

a l g o r ithm use d to c o r r e c t ir on e mission contributions to coba lt is a ppa r e ntly Ir on



### Thir ty

- e ig ht sa mple r e sults we r e inc l ude d in the sa mple se t, two sa mple s with iron concentrations g r eater than 50,000  g/ L
, one sa mple with ir on c onc e n tr a tion le ss tha n

DISCUSSION OF RESULTS 30Lithium 

### the MDL
, and two samples were not analy z ed because of t h e l ack of sam p l e . The Onesa mple Sig n Te st implie s tha t substa ntia l differences ex ist between I C P–OES and F

–AAS results for the samples having iron concentrations between 40 and 19,000  g/ L (p-value=0.0002, n=38, see fig

. 20). Over 80
pe r c e n t of the I C P–OES r e sults we r e le ss tha n the former method (a median difference of only 80  g / L ) probabl y because of i t s l o wer MDL

. The slope of the reg r ession equation (0.87  0.03) shows a neg a tive bias of more tha n 10 pe r c e n t in I C P–OES r e sults, a le ve l
t h at i s accept a bl e consi d eri n g t h e wi de
concent r at i on rang e of t h e sam p l e s anal y z ed. W h en the concentration rang e is narrowed to include samples with concentrations from 440 to 4,500  g / L iron (the concentration boundaries where 50 percent of the iron

r e sults oc c u r )
, the r e is no sig n if ic a n t dif f e r

ence between the two methods. Six t e e n sa mple s ha ving lithium concentrations less than 10  g / L
, the methodreporting limit for the former method F

– AAS,

we r e omitte d f r o m the da ta se t. The dif f e r

ences bet w een anal y t i cal resul t s for F–AAS
, I C P–OES, and I C P–MS were found to be
sta tistic a lly insig n if ic a n t using the Kr uska lW a llis Test (p-value= 0.9191, see fig

. 22b). The sc a tte r g r a m of I C P–OES in r e la tion to F

–AAS data indicate slig ht nonlinearity
, however, the slope interval of 0.90  0.09 i ndi cat es t h e neg a t i v e bi as i s i n si g n i f i cant (see f i g

. 22a )

. The slig ht positive bia s ( s lope inte r v a l 1.1  0.1) between F

– AAS and I C P– MS is a l so ne g lig ible

.

M a gne s i um


### The upper calibration limit for
mag n esium by the F

–AAS method is 50 mg /L

. This limita tion r e duc e d the da ta se t to 41

sa mple s f o r

whic h no sta tistic a lly sig n if ic a n t difference between I C P–OES and F

– AAS results was indicated (p-value=0.6440, see fig

. 23). Reg r ession an al y s i s i ndi cat ed onl y a minor 7 percent neg a tive bias in the I C P–OES results (slope=0.93  0.03) probably because of the lowe r va r i a b ility in the I C P–OES da ta se t (see the box plot in fig

. 23). L ead



### B ecause of the insensitivity of the lead emission waveleng th, onl y four samples had l ead concent r at i ons t h at are m easurabl e usi n g I C P–O E S. N one the l e ss, I C P–O E S r e sults f o r t h ese sam p l e s were i n ex act because t h e concentrations were less than a factor of two
g r eat er t h an t h e MDL of 50  g / L

. The number of

r e sults c o mpa r ing I C P–MS to GF –AAS

wa s r e duc e d to 31 by e limina ting nine sa mple s having lead concentrations less than the GF

– AAS MDL and three samples having lead concentrations g r eater than the upper calibration limit of 100  g / L for I C P

– MS

. The One-sample Sig n Test sug g e sted that
t h ere was no si g n i f i cant di fference bet w een I C P–MS and GF –AAS results (p-value =0.2810, see fig

. 21). This result is supported by linear reg r ession coefficients that show no
sy stematic errors or offset (slope=0.98  0.06 and y -intercept=0.12  1.3, for n=31). M a n g a n ese 

### The sample set was reduced to 36 by

e limina ting one sa mple ha ving ma ng a n e s e

c onc e n tr a tion le ss tha n the r e por ting limit by F

–AAS and six samples having mang anese concentrations g r eater than 1,000  g/ L
, t h e I C P–MS upper calibration limit. Results of the Kr uska l- Wa llis Te st sug g e st tha t the r e a r e no si g n i f i cant di fferences am ong t h e form er F

–AAS method, I C P–OES, and I C P–MS (p-value=0.8669, see fig

. 24b) for samples having mang anese concentrations rang ing from 6 to 870  g / L

. However, I C P

– OES provided somewhat more accurat e resul t s for

DISCUSSION OF RESULTS 31

### the sa mple se t whe n c o mpa r e d to F

–AAS, a s indicated by its mean rank, than did I C P–MS. B o th proposed methods g a ve marg inally lower results than the former F

– AAS method. However, the slopes for I C P–OES (0.99  0.04, n=36) and I C P–MS (0.94  0.05, n=36) in relation to F

– AAS showed no bias (see fig

. 24a). 0.2  g / L

. The slope of the reg r ession sug g e sts that the I C P–MS data are neg a tively biased by about 10 percent when compared to GF –AAS. This bias would represent from 0.2 to 0.8  g/ L for 50 percent of the samples.

S e le nium


### Only f

our sa mple s have selenium concentrations g r eater than 0.8  g / L, t h e M D L for the former method GF –AAS. Using this limite d, nor ma lly distr i bute d da ta se t, the Student t -Test i ndi cat ed t h at t h ere were no sig n ificant differences between I C P–MS and GF –AAS results (p-value=0.3670). Althoug h not presented in fig u re 27, the One-sample Sig n Test also indicated no sig n ificant difference (p-value=0.62) . Close ex amination of the data shows that I C P–MS measured le ve ls up to two time s its MDL ( 2  g / L ) in 4 of the 40 samples in which GF –AAS detected less than 0.8  g / L

. However, this apparent discrepancy is not unus ual because of the inhe r e nt limita tions of me a s ur ing sa mple s ne a r the MDL

. M o ly bde num



### All the sa mple s ha d moly bde num

c onc e n tr a tions le ss tha n the I C P–OES MDL (about 20  g / L ) , therefore, only I C P–MS could be compared to the GF –AAS. Only 28

sa mple s c o mpose d the da ta se t; 15 sa mple s had moly bdenum concen tr a tions le ss tha n either the I C P–MS or GF –AAS MDL s . The One-sam p l e S i g n Test sug g e st ed t h at t h ere was no si g n i f i cant di fference bet w een I C P

– MS and GF –AAS results (p-value=0.5716, see fig

. 25) for the sample set having molybdenum concentrations from about 0.4 to 13
 g / L

. I n addition, no bias was indicated by the reg r ession analy s is (slope=1.0  0.2).

Nickel Silv er


### Eig h ty percent of the sa mple s ha ve ni ckel concent r at i ons l e ss t h an t h e I C P

– OES MDL

. Of the se ve n r e ma ining sa mple s, f i ve

we r e only two time s g r e a t e r tha n the MDL of 20  g / L

. Two samples having g r eater than 100  g / L ni ckel com p ared favorabl y (wi t h i n 2 to 20 percent) to the I C P–MS and GF –AAS

r e sults. The da ta se t use d f

o r

c o mpa r ing I C P– MS to GF –AAS was composed of 34 samples; six samples were omitted because the nickel concentration was less than the GF –AAS or I C P

– MS MDL and t h ree because t h e ni ckel concentration ex ceeded the upper calibration limit f o r

I C P–MS. Sta tistic a l a n a l y s is of the dat a set i ndi cat es t h ere i s a si g n i f i cant difference between I C P–MS and GF –AAS results (p-value=0.0243, see fig

. 26) even thoug h the median difference was only Only one sample had silver at
concent r at i on l e vel s g r eat er t h an t h e GF–AAS MDL of 0.1  g / L ; a ll the sa mple s we r e le ss than the I C P–OES MDL

. The sing le GF

– AAS result (2.0  g / L ) com p ared favorabl y t o the I C P–MS result of 2.1  g/ L

.

S odium



### S i g n i f i cant di fferences bet w een I C P

– OES and F

–AAS results (p-value=0.0046, n=33, see fig

. 28) are sug g e sted bythe Onesample Sig n Test. Seve nty -five percent of the I C P

– OES resul t s were g r eat er t h an t h e corresponding F

–AAS m easurements. The median difference was only about 0.7 mg /L for sodium concentrations rang ing from 0.7 to 38 mg /L . A slig ht positive bia s in the I C P–

DISCUSSION OF RESULTS 32

### are provided separate l y for I C P

– OES and I C P–MS in the following parag r aphs. Poor performance in an y of the evaluation processes for an el em ent i s speci fi cal l y addressed for each method. OES results (slope=1.08  0.02) mig ht be

r e la te d to dif f e r e nc e s in calibration standards.

S t r ontium



### Thir ty

- s e v e n sa mple s c o mpose d the da ta set used to compare the methods; six samples
were not anal y z ed because of t h e l ack of

sam p l e vol um e. S t at i s t i cal anal y s i s i ndi cat ed
t h ere was no si g n i f i cant di fference bet w een the method results (p-value=0.9369, see fig

. 29b) and no sig n ificant bias was implied in the
reg r essi on coeffi ci ent s

. Summary of Test R esult s f o r Inductiv e ly Coupled Plasma–Optical Emission Spect romet r y

( I C P –OES)

Most resul t s from S t andard R e ference Wa te r Sa mple ( S RWS) a n a l y s e s , spike recoveri es for si x nat u ral whol e-wat e r dig e sts, and the analy s is of 43 natural whole-water dig e sts show that aluminum, barium, bery llium, boron, cadmium, calcium, copper, iron, lead, lithium,

ma g n e s ium, ma ng a n e s e , moly bde num, nickel, silicon, silver, sodium, strontium, vanadi um , and z i nc can be accurat e l y de te r mine d using I C P–OES. Some cal ci um , m a g n esi u m , m a ng anese, and vanadium SRW S data are outside the 1  interval about the most probable value (MPV) but within the 1.5  inte r v a l tha t is acceptable by National W a ter Quality L a boratory (NW Q L ) criteria. Z i nc and silver concentrations in one SRW S and ni ckel i n t w o S R W S s are g r eat er t h an t h e 1.5  interval of the MPV. Spike recoveries in two g r ound-water a nd four surface-water sample dig e sts rang ed from 90 to 110 percent for al l el em ent s . El em ent a l resul t s for a larg e number of dig e sted natural whole

- wa te r sa mple s a g r e e with f o r

m e r methods of analy s is for most elements. Eva l ua tion of the s e r e sults f o r

be r y llium, cadmium, lead, moly bdenum, nickel, and silver are constrained by a small number of

sam p l e resul t s because concent r at i ons are less than the I C P–OES method detection limits ( M DL s) . All othe r da ta indic a t e tha t samples having concentr a tions g r e a te r tha n MDL for t h ese el em ent s can be accurat e l y

a n a l y z e d. The va na dium a nd silic on evaluations were based only on SRW S and Zinc



### Twe n ty

- s ix sa mple s we r e not inc l ude d in the comparison of I C P–OES, I C P–MS, and the former method F–AAS because either the

z i nc concentration was le ss tha n I C P–OES or F

–AAS MDL s or the z i nc concentration was
g r eater than the upper calibration limit for F

– AAS. Sta tistic a l a n a l y s is of the r e ma ining 17

sa mple s indic a t e d tha t the r e we r e no sig n ificant differences in the results obtained by the three methods (p-value=0.8097, see fig

. 30b) althoug h the mean rank for I C P–OES is slig htly hig h er than for F

–AAS. The Onesample Sig n Test sug g e sted that there was no si g n i f i cant di fference bet w een I C P

– MS and F

–AAS (p-value=0.8388, n=26, see fig

. 30c) for the ex tended data set. However, the slopes indicated about a 10-percent neg a tive bias in the I C P–MS r e sults c o mpa r e d to only 4 percent for I C P

– OES (fi g

. 30a).

CONCLUS IONS

Re sults f r o m SRWS, spike r e c ove r i e s for six natural whole-water dig e sts, and the analy s is of 43 natural whole-water dig e sts were used t o eval uat e t h e overal l accuracy and

va r i a b ility of I C P–OES a nd I C P–MS. The conclusions derived from a ll the s e te st r e sults provide an accurate estimate of the ex pected analy tical performance of the new methods. Summaries of results of the evaluation process

CONCLUSIONS 3 3

### spike recovery data because former methods
are not avai l a bl e at NW QL

. moly bdenum, nickel, selenium, silver,
str ontium, tha llium, ur a n ium, a nd zinc c a n be det e rm i n ed accurat e l y by usi n g I C P

– MS. All e l e m e n ta l r e sults we r e within
 1.5  of t h e MP V for al l S R W S s ex cept f o r

be r y llium a nd lithium in one SRWS. Spike recovery results were 100  10
pe r c e n t e x c e p t f o r

be r y llium, c a d mium, chrom i u m , and si l v er. These el em ent s are only marg inally outside the  10 percent acceptance limit. The spike concentrations, howev er, were g e nerally le ss tha n 10  g / L ex cept for chrom i u m

. Because of t h e l o w spi k e l e vel s and accept a bl e accuracy for S R W S s and whole-water dig e sts, t h ese four el em ent s

c a n most like l y be de te r mine d a c c u r a te ly by I C P

– MS . The accuracy achi eved i n t h e SRW S and spike recovery data for antimony , selenium, and silver is not strong ly supported with whole-water di g e st resul t s because of t h e sm al l num ber of

sa mple s with de te c t able concentrations. Ne ve r t he le ss, the pr oba bility is hig h tha t accurat e det e rm i n at i on of t h ese el em ent s can be achieved. Only c h r o mium a nd c oba lt e x hibite d unaccept a bl e perform ance i n sel ect ed t e st s. Chr o mium r e sults f o r

whole

- wa te r dig e sts

we r e c onsiste ntly mor e tha n 50 pe r c e n t lowe r than the former method results even thoug h
t h e concent r at i ons were g r eat er t h an t h e MDL

. The suppression of the chromium emission for the whole-water dig e sts is apparently not be ing a d e qua te ly c ontr o lle d by the y ttr ium internal standard. Th is suppression is not apparent in the SRW S or spike-recovery data and could possibly be re la te d to the dissolve d

solid concentration in the dig e sts or an unide ntif ie d spe c t r a l inte rference. Therefore, the de te r mina tion of c h r o mium by I C P–OES is not recommended without further investig ations.

The eval uat i on of t h e accuracy of cobal t resul t s for t h e whol e-wat e r di g e st s was difficult because of the limited number of

sa mple s; mor e tha n 90 pe r c e n t of the

m easurem ent s were l e ss t h an t h e MDL

. The severe direct-spect ral overlap, however, prevent e d accurat e cobal t det e rm i n at i ons whenever t h e i r on concent r at i on ex ceeded 2,000  g / L

. Because nat u ral whol e-wat e r dig e sts likely contain substantial amounts of iron, the determination of cobalt will alway s be problematic. Theref or e , the de te r mina tion of cobalt by I C P–OE S is recommended only when samples have less than 2,000  g Fe / L

. Thallium and uranium accuracy is based only on SRW S and spike recovery data because former methods for de te r mina tion of the s e e l e m e n ts in whole

water dig e sts are not available at NW QL

. Subsequent to conducting this evaluation, a new S R W S (T139) became available that ha s MPV f o r

tha llium ( 3.1  0.8  g / L ) and uranium (5.0  0.2  g / L ) . I C P–MS results f o r

tha llium a nd ur a n ium a r e within the 1  -confi d ence i n t e rval s of t h e MP Vs. These el em ent s al so are g e neral l y unaffect ed by spect ral i n t e rferences because of t h ei r hi g h m a sses. Summary of Test R esult s f o r Inductiv e ly Coupled Plasma–Mass Spect romet r y

( I C P –M S)

Most results from SRW S analy s es, spike recoveri es for si x nat u ra l whole-water dig e sts, and the analy s is of 43 natural whole-water dig e sts show that aluminum, antimony
, ba r i um, be r y llium, c a d mium, c h r o mium, cobalt, copper, lead, lithium, mang anese, W hole-water dig e st results for boron show considerable deviation from the former direct current plasma–atomic

e mission spe c t r o me tr y

( D CP–AES)

CONCLUSIONS 3 4

### method. The slope of th e reg r ession indicates tha t I C P–MS r e sults a r e c onsiste ntly two time s g r eater than the former method. B o x plots and scatterg rams also show considerable variation throug hout the concentration rang e. Even thoug h SRW S and spike recovery data do not i ndi cat e any probl em for the de te r mina tion of boron, apparently some fo rm of interference is affect i n g t h e accuracy of resul t s . C onseque ntly , the de te r mina tion of boron by I C P– MS is not recommende d without additional investig ations.

Ac c u r a te de te r mina tion of c h r o mium by I C P

– MS has been shown t o be accept a bl e by the data presented here. Correction for

c h lor i ne

- b a s e d mole c u la r ion inte r f e r e nc e , however, has been base d on matrix matching the c a libr a tion sta nda r d s to the in- bottle dig e sts. This method of correction can become problematic. I n a small number of i n st ances, t h e deg r ee of accuracy has been found to be unacceptable.

The bulleted list below provides a

suc c i nc t outline of the ma jor c onc lusions of this report. I n addition to analy tical perform ance com p ari s ons, sug g e st i ons are provided for selectin g a ppr opr ia te me thodolog y and the potential effect of the I C P– OES and I C P–MS methods on long -term trend

a n a l y s is in wa te r

- qua lity studie s

.

 MDL s for I C P

– MS are bet w een 5 and 1,000 times lower than I C P–OES. I C P– MS MDL s a r e simila r in ma g n itude to f o r

m e r g r aphi t e furnace–at om i c absorpt i on spect rophotometry (GF

–AAS) methods and MDL s for both I C P–MS and I C P–OES are much l o wer t h an form er fl am e–at om i c absorpt i on spectrophotometry (F –AAS) methods.

 The short

- and l ong -t erm accuracy of I C P

– OES and I C P

– MS was accept a bl e for t h e reference m a t e ri al s st udi ed. Greater than 90 percent of t h e el em ent s were wi t h i n 1  of the most probable value.

 For m o st el em ent s , I C P

– MS i s the method of choice whenever concentrations are less than 100  g/ L

. Conversely
, I C P–OES performs better at concentrations g r eater than 1,000  g/ L

.

 The me dia n long

- t e r m va r i a b ility in e l e m e n ta l r e sults f r o m a simula te d whole

wat e r sam p l e (S R W S W W -1) was 2 t o 3 time s lowe r f

o r

I C P–MS tha n f o r

I C P–OES. Nevertheless, there was somewhat less

va r i a b ility in r e sults f r o m I C P–OES f o r l i g ht er el em ent s (< 60 am u) and whenever el em ent a l concent r at i ons were g r eat er t h an 100  g/ L

.

 Shor t- te r m a n a l y tic a l va r i a b ility decreased with method sensitivity ; therefore, the r e is le ss va r i a b ility in r e sults f r o m I C P– MS, e s pe c i a lly a t lowe r c onc e n tr a tion le ve ls.

 Mat r i x i n t e rferences affect ed t h e de te r mina tion of lig hte r elements (< 60 amu) in selected samples by I C P–MS; however, the ma x imum e r r o r wa s 25 pe r c e n t.

 Data from 43 surface- and g r oundwa te r sa mple s indic a t e d the r e wa s no sig n ificant method bias for 90 percent of the

e l e m e n ts te ste d. Only c h r o mium ( b y I C P– OES) and boron (by I C P–MS) results were unaccept a bl y bi ased.

 Da ta f

r o m I C P–MS will ha ve the hig h e s t pr oba bility of a f f e c ting long

- t e r m tr e nds in wa te r

- qua lity studie s . F o r

ex ample, more than 50 percent of the wholewat e r di g e st s anal y z ed had cadm i u m , chromium, lead, moly bdenum, nickel, and

z i nc concentrations less than the I C P–OES MDL s . The level of accuracy and variability for concentrations less than 100  g/ L will be substa ntia lly dif f e r e nt tha n f o r

CONCLUSIONS 3 5

### handbook for mass spectrometry applications: Sturbridg e , Mass., 64 p. most former methods. Data from I C P–OES will have somewhat less of an effect.

 I C P

– OES and I C P

– MS are st at e-ofthe

- a r t multie le me nt te c hnique s tha t a r e mor e effi ci ent and cost effect i v e t h an form er US GS sing le-element methods such as F

–AAS, GF

– AAS , or DC P

– AES

. For t h ese reasons t h ey are the methods of choice. Hoffman, G.L ., F i shman, M.J ., and Garbarino, J

. R., 1996, Methods of analy s is by the U.S. Geolog ical Sur v e y Na tiona l Wa te r Qua lity L a bor a t or y

— I n

- bottle a c i d dig e stion of whole-water samples: U.S. Geolog ical Survey Open-F ile Report 96-225, 28 p. RE FE RE NCE S CITE D

Am eri can S o ci et y for Test i n g and Mat e ri al s, 1995, Annual book of ASTM standards, Section 11, W a ter (D1193, Standard speci fi cat i on for reag ent wat e r): Philadelphia, v. 11.01, p. 122–124. Montaser, Akbar, and Golig htly , D.W
., eds., 1992, I nductively coupled pl asm a s i n anal y t i cal at om i c spectrometry : New York, VC H Publishers, I n c., 2nd Edition, 1017 p.
B oumans, P.W

. J

. M., ed., 1987a, I nductively coupled plasma emission spectroscopy

— Part I
, Methodolog y , instrumentation, and performance: New York, J ohn W iley & Sons, 584 p. Thermo J a rrell-Ash, 1991, Operator’s manual: F r anklin, Mass.

U.S. Environmental Protection Ag ency , 1992, Methods for the determination of

me ta ls in e nvir onme n ta l sa mple s: B o c a Ra ton, CRC Pre ss, I n c ., 339 p. ______1987b, I nductively coupled plasma emission spectroscopy —Part I I
, Applications and f undamentals: New York, J ohn W iley & Sons, 486 p. ______1994, Guidelines establishing test procedures for the analy s is of pollutants (Part 136, Appendix B

. Definition and Procedure for the Determination of the Method Detection L imit—Revision 1.11): U.S. Code of F e deral Reg u lations, Title 40, Revised as of J u ly 1, 1994, p. 635–637. F i shman, M.J ., and F r iedman, L

. C., 1989, Methods for determination of inorg a nic substances in water and fluvial sediments: U.S. Geolog ical Survey Techniques of W a ter-Resources I nvestig ations, book 5, chap. A1, 545 p.

F i shman, M.J ., ed., 1993, Methods of analy s is by the U.S. Geolog ical Survey National Wa te r Qua lity L a bor a t or y

— De te r mina tion of i norg a nic and org a nic

c onstitue n ts in wa te r a nd f l uvia l sediments: U.S. Geolog ical Survey Open-F ile Report 93-125, 217 p. VG Elemental, 1988, PlasmaQuad operators manual: B e verly
, Mass., 164 p.

______1994, PlasmaQuad PQVision software manual, 335 p.

Galileo Electro-Optic Corporation, 1991, Cha nne ltr on e l e c t r on multiplie r

CONCLUSIONS 3 6

# APPENDIX

Figure s 1

– 

# 30

T a b l es 8

– 

# 20

CONCLUSIONS 3 7I n te rn a l s t a n d a rd
, su rf ac t a n t

Sa m p l e

4

- tu rn c o il Pe r i s t a l t i c
pum p 0. 80 m L / m i n 0. 16 m L / m i n

nebu l i z e r To



### Per i s t a l t i c pu m p t ubi ng co l o r c o de

0. 16 m L / m i n or a n g e /y el l o w 0. 80 m L / m i n re d

m L / m i n , m i l l i l i t e rs p e r m i n u t e



### F i gure 1a. Sample introduction manifold fo r inductively coupled plasma–optical emission spectrometric method.

D e bubb l e r Wa s t e I n te rn a l s t a n d a rd
, su rf ac t a n t
Ai r Sa m p l e

1 2

- tu r n c o il Pe r i s t a l t i c
pum p 1 m L /m in 0. 05 m L / m i n 0. 10 m L / m i n 0. 32 m L / m i n

nebu l i z e r To



### Per i s t a l t i c pu m p t ubi ng co l o r c o de

0. 32 m L / m i n bl ack 0. 10 m L / m i n o r an ge/ g r een 0. 05 m L / m i n o r an ge/bl u e 1 m L / m i n gr a y

m L / m i n , m i l l i l i t e rs p e r m i n u t e

Figur e 1 b

. Sam p le intr oduc tion m anif o ld f o r induc tively c oupled plas m a–m as s s pec tr om etr i c
m e thod.

A PPENDIX 390 2 0 0 40 0 6 00 80 0 0 2 4 6 8 10APPARENT65CuCONCENTRATION,INMICROGRAMS PERLITER [Y]



### S U LF AT E CO N C EN TR AT IO N, IN MILL IG RAMS PE R LI TER [ X ]

Figur e 2 a

. Sulf ate inter f er enc e on c opper deter m i nations by induc tively c oupled plas m a–m as s
s pec tr om etr y . T he linear r egr es s i on equation is y = 0.021 + 0.013x ( R 2 = 0.9999)

.

0 2 00 4 0 0 6 00 8 0 0 0 1 2 3 4 5 6APPARENT66Zn CONCENTRATION,INMICROGRAMSPERLITER[Y]



### S U LF A T E C O N C E N TR A T IO N
, I N MIL L IGR A MS PE R LI TER [X ]

Figur e 2 b

. Sulf ate inter f er enc e on z i nc deter m i nations by induc tively c oupled plas m a–m as s
s pec tr om etr y . T he linear r egr es s i on equation is y = 0.48 + 0.0068x ( R 2 = 0.9977)

.

A PPENDIX 400 200 400 600 800 1 00 0 0 200 400 600 800EXPERIMENTALSULFATECONCENTRATION,INMILLIGRAMSPER LITER[Y]



### THE O RE TICAL S U L F A TE CO NCE N TR ATIO N, IN M I LL IG RAM S PE R L I TE R [ X ]

Figur e 3

. Ac c u r a c y of induc tively c oupled plas m a–m as s s pec tr om etr i c s u lf ate deter m i nations

us ing 32 S 16 O + r e s pons e. T he poly nom ial r egr es s i on equation is y = –7.9 + 1.2x – 0.0004x 2 (R 2 = 0.9998) . Er r o r bar s r epr es ent 1 s t andar d deviation.

0 1 00 2 0 0 30 0 4 0 0 50 0 6 00 24 26 28 30 32 34 36 U n co rr ec t e d Corre ct e d65CuCONCENTRATION,INMICROGRAMSPER LITER



### SU L F ATE C O NCEN T R A T IO N, IN MILL IG RA MS P E R LITER

Figur e 4 a

. Ac c u r a c y of s u lf ate inter f er enc e c o r r e c t ions on c opper deter m i nations by induc tively

c oupled plas m a–m as s s pec tr om etr y

.

A PPENDIX 410 1 00 20 0 3 0 0 4 0 0 5 00 60 0 24 26 28 30 32 34

Un co rre c t ed C o r r e cted66ZnCONCENTRATION,INMICROGRAMS PERLITER



### S U L F AT E C O N C EN T R AT I O N
, I N M I L L I G R A M S PE R L I T E R

Figur e 4 b

. Ac c u r a c y of s u lf ate inter f er enc e c o r r e c t ions on z i nc deter m i nations by induc tively

c oupled plas m a–m as s s pec tr om etr y

.

A PPENDIX 4215 0 17 5 20 0 22 5 25 0 27 5 30 0
AL UM I NUM

18 0 19 0 20 0 21 0
BAR I U M

9 10 11 12 13
BE RY L L I UM

10 0 11 0 12 0 13 0 14 0 15 0 16 0 BO R O N

10 12 14 16 18
CA DM I U M

10 11 12 13 14
CA L C I U M , I N M I LLI G R A M S P E R LI T E R

MP V I C P

- O E S 8 10 12 14 16 18
CH RO M I U M

MP V I C P

- O E S 9 10 11 12 13 14 15 C O BAL T

MP V I C P

- O E S 27 28 29 30 31 32 33CONCENTRATION,INMICROGRAMS PER LITER

CO P P E R

Figur e 5 a

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 107. Er r o r bar s r epr es ent 1 s t andar d deviation f r om the m ean.

A PPENDIX 4340 45 50 55 60
IR O N

170 180 190 200 210
LI T H I U M

1. 7 5 2. 0 0 2. 2 5 2. 5 0
M A G N ESI U M , I N M I LLI G R A M S P E R L I TE R

35 40 45 50 55
M A NG AN E S E

10 15 20 25 30 35
NI C K E L

7. 0 7. 5 8. 0 8. 5
SI L I C A , I N M I LL I G R A M S P E R LI TE R

MP V I C P

- O E S 4 6 8 10 12 14 16 18 20
SI L VER

MP V I C P -O E S 18 19 20 21 22 23
SO D I U M , I N M I LL I G R A M S P E R LI TE R

MP V I C P

- O E S 50 55 60 65 70CONCENTRATION,INMICROGRAMSPERLITER

ST R O N T I U M

Figur e 5 a

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 107—Continued.

A PPENDIX 44MP V I C P

- O E S 10 12 14 16 18CONCENTRATION,INMICROGRAMSPERLITER

V A NADI UM

MP V I C P

- O E S 60 65 70 75 80 85 90 ZI N C

Figur e 5 a

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 107—Continued.

A PPENDIX 45150 175 200 225 250 275 300
AL U M I N UM

5 7 9 11 13 15
AN T I M O NY BA RI U M

18 0 18 5 19 0 19 5 20 0 20 5 21 0

BE R Y L L I U M

9 10 11 12 13 14 15 16
BO R O N

10 0 11 0 12 0 13 0 14 0 15 0 16 0 17 0 18 0

C ADM I U M

11 12 13 14 15 16 17

MP V I C P

- M S 10 12 14 16 18 20
CH RO M I UM

MP V I C P

- M S 9 10 11 12 13 14
CO BAL T

MP V I C P -MS 27 28 29 30 31 32 33CONCENTRATION,INMICROGRAMS PERLITER

CO P P E R

Figur e 5 b

. Long- ter m induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in

r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 107. Er r o r bar s r epr es ent 1 s t andar d deviation f r om the m ean.

A PPENDIX 4620 22 24 26 28 30 32
LE A D

17 5 18 5 19 5 20 5 21 5 22 5 23 5 24 5
LI TH I U M

35 40 45 50 55
M A N G A N ESE

12 13 14 15 16 17 18

M O L Y BD E N UM

22 24 26 28 30 32 34

NI C K E L

8 9 10 11 12 13 14 SEL E N I U M

MP

V I C P

- M S 9 10 11 12 13 14 15
SI L VER

MP V I C P

- M S 56 58 60 62 64 66
S T RO NT I U M

MP V I C P

- M S 60 65 70 75 80 85 90CONCENTRATION,INMICROGRAMS PER LITER

ZI N C

Figur e 5 b

. Long- ter m induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in

r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 107— Continued.

A PPENDIX 4712 5 15 0 17 5 20 0 22 5
AL UM I N UM

40 42 44 46 48
BAR I U M

11 12 13 14 15 16
BE RY L L I U M

15 20 25 30 35 40 BO R O N

0 2 4 6
CADM I U M

10 11 12 13
CA L C I U M , I N M I LLI G R A M S P E R LI TE R

MP

V I C P

- O E S 16 18 20 22
CHR O M I U M

MP V I C P

- O E S 2 4 6 8 CO BAL T

MP V I C P

- O E S 35 40 45 50 55CONCENTRATION,INMICROGRAMSPERLITER

IR O N

Figur e 6 a

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 119. Er r o r bar s r epr es ent 1 s t andar d deviation f r om the m ean.

A PPENDIX 4855 57 59 61 63 65
LI T H I U M

2. 8 2. 9 3. 0 3. 1 3. 2 3. 3 3. 4
M A G N ESI U M , I N

M I L L IG R A

M S

P E R L I T E R

30 32 34 36 38 40
MA N G

A N E S E

0 5 10 15 20 25
M O L Y BD E N UM

5 10 15 20 25 30
NI C K E L

8. 4 8. 6 8. 8 9. 0 9. 2 9. 4 9. 6 SI L I C A , IN M I L L IG R A M S

P E R L I T E R

MP

V I C P

- O E S 0 2 4 6
SI L V ER

MP V I C P

- O E S 19 20 21 22
S O DI UM , I N

M I L L IG R A

M S

P E R L I T E R

MP V I C P

- O E S 66 68 70 72 74 76 78 80CONCENTRATION,INMICROGRAMS PER LITER

ST R O N T I U M

Figur e 6 a

. Shor t- ter m induc tively c oupled plas m a–opt ic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 119—Continued.

A PPENDIX 49MP V I C P -O E S 2 3 4 5 6 7CONCENTRATION, INMICROGRAMSPER LITER

V ANA DI U M

MP V I C P

- O E S 15 20 25 30 35 ZI N C

Figur e 6 a

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 119—Continued.

A PPENDIX 5013 0 14 0 15 0 16 0 17 0 18 0 19 0 20 0 21 0
AL U M I N UM

6 7 8 9 10 11
AN T I M O N Y B ARI U M

40 42 44 46 48 50

BE RY L L I UM

11 12 13 14 15 16 17
BO R O N

10 20 30 40 50

CA DM I U M

2. 2 5 2. 5 0 2. 7 5 3. 0 0 3. 2 5

MP V I C P -MS 16 17 18 19 20 21 22
C HRO M I UM

MP V I C P -MS 4. 0 4. 5 5. 0 5. 5 6. 0 6. 5
CO BAL T

MP V I C P -M S 0. 5 1. 0 1. 5 2. 0 2. 5 3. 0 3. 5CONCENTRATION,INMICROGRAMS PER LITER

C O PPE R

Figur e 6 b

. Long- ter m induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in

r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 119. Er r o r bar s r epr es ent 1 s t andar d deviation f r om the m ean.

A PPENDIX 515. 0 5. 5 6. 0 6. 5 7. 0 7. 5 8. 0
LE A D

50 55 60 65 70
LI TH I U M

30 32 34 36 38 40
M ANG A N E S E

9 10 11 12 13 14 15

M O L Y BDE NU M

17 19 21 23 25

NI CK E L

8 9 10 11 12 SEL EN I U M

MP V I C P

- M S 1 2 3 4 5 6
SI L VER

MP V I C P -MS 60 65 70 75 80
ST R O N T I U M

MP V I C P -M S 18 21 24 27 30CONCENTRATION,INMICROGRAMS PER LITER

ZI N C

Figur e 6 b

. Long- ter m induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in

r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 119— Continued.

A PPENDIX 5240 45 50 55 60 65 70
A L UM I N UM

13 0 13 5 14 0 14 5 15 0 15 5 16 0
B ARI UM

32 34 36 38
B E RY L L I UM

27 0 28 0 29 0 30 0 31 0 32 0 BO RO N

22 24 26 CA DM I U M

6. 5 0 6. 7 5 7. 0 0 7. 2 5 7. 5 0
CA L C I U M , I N M I LLI G R A M S P E R LI TE R

MP

V I C P -O E S 30 35 40 45 50
CH RO M I UM

MP V I C P

- O E S 10 15 20 25 30 C O BAL T

MP V I C P -O E S 80 82 84 86 88 90CONCENTRATION,INMICROGRAMS PER LITER

CO P P E R

Figur e 7 a

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 133. Er r o r bar s r epr es ent 1 s t andar d deviation f r om the m ean.

A PPENDIX 5320 25 30 35 40

IR O N

45 47 49 51 53 55
LI TH I U M

5. 25 5. 50 5. 75 6. 00 6. 25
MA G N E S I U M , I N M I LLI G R A M S P E R LI TE R

11 0 11 5 12 0 12 5 13 0
M A N G ANS E

25 35 45 55 65

M O L Y BDE N U M

10 15 20 25 30 35 40
NI CKE L

MP V I C P

- O E S 9. 0 9. 5 10

. 0 10

. 5 11

. 0

S I L I CA, I N M I LLI G R A M S P E R LI TE R

MP V I C P

- O E S 5. 5 6. 0 6. 5 7. 0 7. 5 8. 0 8. 5
SI L V E R

MP V I C P

- O E S 28 29 30 31CONCENTRATION,INMICROGRAMS PER LITER

S O DI UM , I N M I LLI G R A M S P E R LI TE R

Figur e 7 a

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 133—Continued.

A PPENDIX 54MP V I C P

- O E S 11 5 12 0 12 5 13 0 13 5
S T RO NT I U M

MP V I C P

- O E S 8 10 12 14 16
V ANADI UM

MP V I C P

- O E S 30 40 50 60
ZI N CCONCENTRATION,INMICROGRAMSPERLITER

Figur e 7 a

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 133—Continued.

A PPENDIX 5540 45 50 55 60 65 70
A L UM I N UM

9 11 13 15 17 19 ANT I M O N Y BA RI UM

130 135 140 145 150 155 160

BE RY L L I UM

30 32 34 36 38 40
BO RO N

27 0 28 0 29 0 30 0 31 0 32 0 33 0

CA DM I U M

20 21 22 23 24 25 26

MP

V I C P

- M S 34 36 38 40 42 44
C HRO M I UM

MP V I C P

- M S 18 19 20 21 22
CO B A L T

MP V I C P

- M S 80 82 84 86 88 90CONCENTRATION,INMICROGRAMS PER LITER

CO P P E R

Figur e 7 b

. Long- ter m induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in

r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 133. Er r o r bar s r epr es ent 1 s t andar d deviation f r om the m ean.

A PPENDIX 5624 26 28 30 32 34
LE A D

48 50 52 54 56 LI TH I U M

110 115 120 125 130
M A N G A N ESE

35 40 45 50 55

M O L Y BD E N UM

23 25 27 29 31

NI C K E L

16 18 20 22 24 26 SEL E N I U M

MP V I C P

- M S 6 7 8 9
SI L VER

MP V I C P

- M S 11 5 12 0 12 5 13 0
S T RO NT I U M

MP V I C P

- M S 45 50 55 60CONCENTRATION,INMICROGRAMS PER LITER

ZI N C

Figur e 7 b

. Long- ter m induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in

r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 133— Continued.

A PPENDIX 570 5 10 15 20
AL U M I N UM

60 65 70 75 80
BA RI UM

55 57 59 61 63 65
BE R Y L L I U M

0 5 10 15 20 25 BO R O N

45 47 49 51 53 55
CAD M I U M

9. 5 10

. 0 10

. 5 11

. 0 11

. 5

CA L C I U M , I N M I LLI GR A M S P E R LI TE R

MP V I C P

- O E S 70 75 80 85 90
C HRO M I UM

MP V I C P

- O E S 35 37 39 41 43 45 CO B A L T

MP V I C P

- O E S 50 55 60 65 70CONCENTRATION,INMICROGRAMS PER LITER

CO P P E R

Figur e 8

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 135. Er r o r bar s r epr es ent 1 s t andar d deviation f r om the m ean.

A PPENDIX 5821 0 22 0 23 0 24 0 25 0
IR O N

80 90 10 0 11 0 12 0 13 0

LE A D

65 70 75 80 85

LI TH I U M

1. 8 5 1. 9 0 1. 9 5 2. 0 0 2. 0 5 2. 1 0 2. 1 5
MA G N E S I U M , I N M I LLI G R A M S P E R LI TE R

39 0 40 0 41 0 42 0 43 0 44 0 45 0
M A NG AN E S E

50 55 60 65 70 75 80

M O L Y BDE N U M

MP V I C P

- O E S 45 50 55 60 65 70 75
N I CKE L

MP V I C P

- O E S 3. 9 4. 1 4. 3 4. 5 4. 7 4. 9
S I L I CA, I N M I LLI G R A M S P E R LI TE R

MP V I C P

- O E S 8 9 10 11 12 13 14CONCENTRATION,INMICROGRAMS PER LITER

SI L V E R

Figur e 8

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 135—Continued.

A PPENDIX 5928 29 30 31 32 33

SO D I UM , IN M I L L IG R A M S P E R L I T E R

MP V I C P

- O E S 42 44 46 48 50
ST RO NT I U M

MP V I C P

- O E S 48 50 52 54 56 58

V A N ADI UM

MP V I C P

- O E S 35 40 45 50 55
ZI N CCONCENTRATION,INMICROGRAMSPERLITER

Figur e 8

. Shor t- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES)

r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le T 135—Continued.

A PPENDIX 600 5, 000 10, 000 15, 000

A L UM I N UM

0 2 4 6 8 AN T I M O N Y

100 120 140 160 180 200

B A

RI UM

7 8 9 10 11

BE R Y L L I U M

MPV I C P

- O ES I C P- MS -1 5

0 15 30 45 60 75
BO R O N

M P V I C P

- O ES IC P- M S 3 4 5 6 7 8 9CONCENTRATION,INMICROGRAMSPERLITER

CA DM I U M

Figur e 9

. Long- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES) and induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le W W

- 1 . Er r o r bar s r epr es ent 1

s t andar d deviation f r om the m ean.

A PPENDIX 6116 17 18 19 20
CA L C I U M , IN MI L L IG R A

MS

P E R LITE R

15 20 25 30 35 C HRO M I UM

10 12 14 16 18 20
CO B A

L T

20 24 28 32 36 40
C O PP ER

MPV I C P

- O ES I C P- M S 8, 0 0 0 10, 0 0 0 12, 0 0 0 14, 0 0 0 16, 0 0 0 18, 0 0 0 20, 0 0 0
IR O N

MPV I C P

- O ES I C P- MS 15 20 25 30 35CONCENTRATION,INMICROGRAMSPER LITER

LE A

D

Figur e 9

. Long- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES) and induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le W W

- 1 —Continued.

A PPENDIX 6210 15 20 25

LI T H I U M

5 6 7 8 9

MA G N E S I U M, IN M I L L IG R A

M S P E R LIT E R

500 520 540 560 580 600 620 640 660

MA N G A N E S E

2 3 4 5 6 7 8
MO LY B D E NUM

M P V I C P

- O ES IC P- M S 10 20 30 40 50

NI CK EL

MPV I CP

- O E S I C P- M S 3 4 5 6 7 8CONCENTRATION,INMICROGRAMS PER LITER

SEL EN I U M

Figur e 9

. Long- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES) and induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in r e lation to the m o s t
pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le W W

- 1 —Continued



### .

A PPENDIX 6310 20 30 40 50 SI L I C A , I N M I L L I G RA M S

PE R L I T E R

0 1 2 3 4 5
SI LVE R

16 18 20 22

S O DI UM , IN MILLIG R A

M S

P E R LITE R

75 80 85 90 95
S T RO NT I U M

MP V I CP

- O E S I C P- MS 10 15 20 25 30 35

V A

NA

DI UM

M P V I C P

- O ES IC P- M S 50 60 70 80 90 10 0 11 0CONCENTRATION,INMICROGRAMS PER LITER

ZI NC

Figur e 9

. Long- ter m induc tively c oupled plas m a–optic al em is s i on s pec tr om etr i c ( I CP–O ES) and induc tively c oupled plas m a–m as s s pec tr om etr i c ( I CP–MS) r e s u lts in

r e lation to the m o s t pr obable value ( M PV) f o r Standar d Ref e r enc e W a ter Sam p le W W

- 1—Continued.

A PPENDIX 64APPENDIX 65 Figure 10a. Scattergrams and regression analyses showing aluminum whole-water digest data from inductively coupled plasma–optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former direct current plasma–atomic emission spectrometric (DCP– AES) method. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th , 25 th , 50 th , 75 th , and 90 th percentiles; data below the 10 th and above 90 th are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 10b . Box plots and Kruskal-Wallis Test results showing aluminum data from the former direct current plasma–atomic emission spectrometric (DCP–AES) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP–OES, group 1), and inductively coupled plasma–mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -5000 0 5000 10000 15000 20000 25000

DCP-AES, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
0
0.05
0.9750

0.05
0.9750 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

25 931.00 37.24
25 954.00 38.16
25 965.00 38.60 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: Method -5000 0 5000 10000 15000 20000ICP-OES, in μg/L

-5000 0 5000 10000 15000 20000 25000 DCP-AES, in μg/L Scattergram

62.58 -45.25 170.40
0.88 0.86 0.90 Coefficient 95% Low er 95% Upper Intercept DCP-AES, in μg/L Confidence Intervals ICP-OES, in μg/L vs. DCP-AES, in μg/L

-5000 0 5000 10000 15000 20000 25000ICP-MS, in μg/L

-5000 0 5000 10000 15000 20000 25000 DCP-AES, in μg/L Scattergram

-3.85 -108.17 100.47
1.04 1.03 1.06 Coefficient 95% Low er 95% Upper Intercept DCP-AES, in μg/L Confidence Intervals ICP-MS, in μg/L vs. DCP-AES, in μg/LAPPENDIX 66 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 11. Scattergram, box plots, Paired t -Test results, and regression coefficients showing antimony data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupledplasma–mass spectrometry (ICP–MS) for wholewater digests. Concentrations are in micrograms per liter (  g/L). Figure 12a. Scattergrams and regression analyses showing barium whole-water digest data from inductively coupled plasma–optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former flame–atomic absorption spectrophotometric (F–AAS) method. Concentrations are in micrograms per liter (  g/L). -2 0 2 4 6 8ICP-MS, in μg/L

-2 0 2 4 6 8 GF-AAS, in μg/L Scattergram

-2 0 2 4 6 8

GF-AAS, in μg/L ICP-MS, in μg/L

Box Plot -0.14 -2.77 2.49
1.35 0.31 2.38 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

0.62 8 1.09 0.3061 Mean Diff. DF t-Value P-Value ICP-MS, in μg/L, GF-AAS, ... Paired t-test Hypothesized Difference = 0 -100 0 100 200 300 400 500 600 700 800ICP-OES, in μg/L

-100 0 100 200 300 400 500 600 700 800 F-AAS, in μg/L Scattergram

69.55 11.60 127.50
0.63 0.42 0.84 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. F-AAS, in μg/L

-100

0 100 200 300 400 500 600 700 800ICP-MS, in μg/L

-100 0 100 200 300 400 500 600 700 800 F-AAS, in μg/L Scattergram

53.08 -8.49 114.64
0.78 0.56 1.01 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. F-AAS, in μg/LAPPENDIX 67 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 12b. Box plots and Kruskal-Wallis Test results showing barium data from the former flame–atomic absorption spectrophotometric (F– AAS) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP– OES, group 1), and inductively coupled plasma– mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 12c. Scattergram, box plots, Onesample Sign Test, and regression coefficients showing barium data from inductively coupled plasma–optical emission spectrometry (ICP– OES) and inductively coupled plasma–mass spectrometry (ICP–MS) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -100

0 100 200 300 400 500 600 700 800ICP-MS, in μg/L

-100 0 100 200 300 400 500 600 700 800 ICP-OES, in μg/L Scattergram

-7.55 -14.77 -0.34
1.13 1.09 1.17 Coefficient 95% Low er 95% Upper Intercept ICP-OES, in μg/L Confidence Intervals ICP-MS, in μg/L vs. ICP-OES, in μg/L

-100

0 100 200 300 400 500 600 700 800

ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

13
30
0
0.0137 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0 0 100 200 300 400 500 600 700 800

F-AAS, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
4
1.96
0.3754

1.96
0.3749 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

20 667.00 33.35
20 641.00 32.05
20 522.00 26.10 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: MethodAPPENDIX 68 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 13. Scattergram, box plots, Paired t -Test results, and regression coefficients showing beryllium data from inductively coupled plasma–optical emission spectrometry (ICP– OES) and inductively coupled plasma–mass spectrometry (ICP–MS) for whole-water digests. Concentrations are in micrograms per liter (  g/L). Figure 14a. Scattergrams and regression analyses showing boron whole-water digest data from inductively coupled plasma–optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former direct current plasma–atomic emission spectrometric (DCP– AES) method. Concentrations are in micrograms per liter (  g/L). -50

0 50 100 150 200 250 300ICP-MS, in μg/L

-50 0 50 100 150 200 250 300 DCP-AES, in μg/L Scattergram

-17.79 -50.30 14.71
2.01 1.27 2.74 Coefficient 95% Low er 95% Upper Intercept DCP-AES, in μg/L Confidence Intervals ICP-MS, in μg/L vs. DCP-AES, in μg/L

-50

0 50 100 150 200 250 300ICP-OES, in μg/L

-50 0 50 100 150 200 250 300 DCP-AES, in μg/L Scattergram

3.92 -9.12 16.96
0.67 0.38 0.97 Coefficient 95% Low er 95% Upper Intercept DCP-AES, in μg/L Confidence Intervals ICP-OES, in μg/L vs. DCP-AES, in μg/L -2 0 2 4 6 8 10 12 14ICP-MS, in μg/L

-2 0 2 4 6 8 10 12 14 ICP-OES, in μg/L Scattergram

0.18 -0.37 0.72
1.04 0.93 1.14 Coefficient 95% Low er 95% Upper Intercept ICP-OES, in μg/L Confidence Intervals ICP-MS, in μg/L vs. ICP-OES, in μg/L

-2 0 2 4 6 8 10 12 14

ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

-0.30 4 -2.16 0.0974 Mean Diff. DF t-Value P-Value ICP-OES, in μg/L, ICP-MS, ... Paired t-test Hypothesized Difference = 0APPENDIX 69 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 14b. Box plots and Kruskal-Wallis Test results showing boron data from the former direct current plasma–atomic emission spectrometric (DCP–AES) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP–OES, group 1), and inductively coupled plasma–mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 14c. Scattergram, box plots, Onesample Sign Test results, and regression coefficients showing boron data from the former direct current plasma–atomic emission spectrometric (DCP–AES) method and inductively coupled plasma–optical emission spectrometry (ICP–OES) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -50

0 50 100 150 200 250 300

DCP-AES, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
2
12.37
0.0021
12.37
0.0021 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

28 855.00 30.54
28 1495.00 53.39
28 1220.00 43.57 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: Method -200 0 200 400 600 800 1000ICP-OES, in μg/L

-200 0 200 400 600 800 1000 DCP-AES, in μg/L Scattergram

-200

0 200 400 600 800 1000

DCP-AES, in μg/L ICP-OES, in μg/L Box Plot -8.41 -14.60 -2.21
1.00 0.97 1.03 Coefficient 95% Low er 95% Upper Intercept DCP-AES, in μg/L Confidence Intervals ICP-OES, in μg/L vs. DCP-AES, in μg/L

25
11
0
0.0288 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0APPENDIX 70 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 14d. Scattergram, box plots, Onesample Sign Test results, and regression coefficients showing boron data from the former direct current plasma–atomic emission spectrometric (DCP–AES) method and inductively coupled plasma–mass spectrometry (ICP–MS) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 15. Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing cadmium data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupledplasma–mass spectrometry (ICP–MS) for wholewater digests. Concentrations are in micrograms per liter (  g/L). -50

0 50 100 150 200 250 300ICP-MS, in μg/L

-50 0 50 100 150 200 250 300 DCP-AES, in μg/L Scattergram

-17.79 -50.30 14.71
2.01 1.27 2.74 Coefficient 95% Low er 95% Upper Intercept DCP-AES, in μg/L Confidence Intervals ICP-MS, in μg/L vs. DCP-AES, in μg/L

-50

0 50 100 150 200 250 300

DCP-AES, in μg/L ICP-MS, in μg/L Box Plot

5
23
0
0.0009 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0 -1 0 1 2 3 4 5 6 7ICP-MS, in μg/L

-1 0 1 2 3 4 5 6 7 GF-AAS, in μg/L Scattergram

0.03 -2.02E-3 0.06
1.00 0.98 1.02 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

-1 0 1 2 3 4 5 6 7

GF-AAS, in μg/L ICP-MS, in μg/L

Box Plot

8
19
0
0.0522 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0APPENDIX 71 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 16. Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing calcium data from the former flame– atomic absorption spectrophotometric (F–AAS) method and inductively coupled plasma–opticalemission spectrometry (ICP–OES) for wholewater digests. Concentrations are in milligrams per liter (mg/L). Figure 17a. Scattergrams and regression analyses showing chromium whole-water digest data from inductively coupled plasma– optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method. Concentrations are in micrograms per liter (  g/L). -20

0 20 40 60 80 100 120 140 160 180ICP-OES, in μg/L

-20 0 20 40 60 80 100 120 140 160 180 GF-AAS, in μg/L Scattergram

3.86E-3 -2.54 2.55
0.52 0.47 0.58 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. GF-AAS, in μg/L

-20

0 20 40 60 80 100 120 140 160 180ICP-MS, in μg/L

-20 0 20 40 60 80 100 120 140 160 180 GF-AAS, in μg/L Scattergram

3.76 1.01 6.51
1.04 0.98 1.09 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L 0 10 20 30 40 50 60 70ICP-OES, in mg/L

0 10 20 30 40 50 60 70

F-AAS, in mg/L Scattergram

0.48 -0.42 1.38
1.03 1.00 1.06 Coefficient 95% Low er 95% Upper Intercept F-AAS, in mg/L Confidence Intervals ICP-OES, in mg/L vs. F-AAS, in mg/L

0 10 20 30 40 50 60 70

F-AAS, in mg/L ICP-OES, in mg/L Box Plot

3
29
0
<0.0001 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0APPENDIX 72 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 17b. Box plots and Kruskal-Wallis Test results showing chromium data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP–OES, group 1), and inductively coupled plasma–mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 17c. Scattergram, box plots, Onesample Sign Test results, and regression coefficients showing chromium data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupled plasma–optical emission spectrometry (ICP–OES) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 2
3
0
9.71
0.0078

9.71
0.0078 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

15 225.00 15.00
15 447.00 29.80
15 363.00 24.20 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: Method

-20

0 20 40 60 80 100 120 140 160 180

GF-AAS, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

-20 0 20 40 60 80 100 120 140 160ICP-OES, in μg/L

-20 0 20 40 60 80 100 120 140 160 GF-AAS, in μg/L Scattergram

3.86E-3 -2.54 2.55
0.52 0.47 0.58 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. GF-AAS, in μg/L

-20

0 20 40 60 80 100 120 140 160

GF-AAS, in μg/L ICP-OES, in μg/L Box Plot

15
0
0
<0.0001 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0APPENDIX 73 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 17d. Scattergram, box plots, Onesample Sign Test results, and regression coefficients showing chromium data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupled plasma–mass spectrometry (ICP–MS) for whole-water digests. Concentrations are in micrograms per liter (  g/L). Figure 18a. Scattergrams and regression analyses showing cobalt whole-water digest data from inductively coupled plasma–optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method. Concentrations are in micrograms per liter (  g/L). -20

0 20 40 60 80 100 120 140 160 180ICP-MS, in μg/L

-20 0 20 40 60 80 100 120 140 160 180 GF-AAS, in μg/L Scattergram

3.24 1.53 4.94
1.04 1.00 1.09 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

-20

0 20 40 60 80 100 120 140 160 180

GF-AAS, in μg/L ICP-MS, in μg/L Box Plot

3
23
0
<0.0001 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0 -50 0 50 100 150 200 250 300 350 400ICP-OES, in μg/L

-50 0 50 100 150 200 250 300 350 400 GF-AAS, in μg/L Scattergram

193.26 -175.66 562.18
-0.61 -6.40 5.18 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. GF-AAS, in μg/L

10 20 30 40 50 60 70 80 90 100ICP-MS, in μg/L

10 20 30 40 50 60 70 80 90 100 GF-AAS, in μg/L Scattergram

1.10 -15.19 17.40
0.85 0.60 1.11 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/LAPPENDIX 74 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 18b. Box plots and Kruskal-Wallis Test results showing cobalt data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP–OES, group 1), and inductively coupled plasma–mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 18c. Scattergram, box plots, Onesample Sign Test results, and regression coefficients showing cobalt data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupled plasma–mass spectrometry (ICP–MS) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -50

0 50 100 150 200 250 300 350 400

GF-AAS, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
0
5.24
0.0728

5.24
0.0728 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

6 81.00 13.50
6 41.00 6.83
6 49.00 8.17 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: Method -20 0 20 40 60 80 100ICP-MS, in μg/L

-20 0 20 40 60 80 100 GF-AAS, in μg/L Scattergram

0.16 -0.85 1.16
0.87 0.83 0.90 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

-20

0 20 40 60 80 100

GF-AAS, in μg/L ICP-MS, in μg/L Box Plot

24
7
0
0.0033 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0APPENDIX 75 Figure 19a. Scattergrams and regression analyses showing copper whole-water digest data from inductively coupled plasma–optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 19b. Box plots and Kruskal-Wallis Test results showing copper data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP–OES, group 1), and inductively coupled plasma–mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -50

0 50 100 150 200 250 300 350 400ICP-OES, in μg/L

-50 0 50 100 150 200 250 300 350 400 GF-AAS, in μg/L Scattergram

-1.30 -13.71 11.11
0.93 0.79 1.07 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. GF-AAS, in μg/L

-50

0 50 100 150 200 250 300 350 400ICP-MS, in μg/L

-50 0 50 100 150 200 250 300 350 400 GF-AAS, in μg/L Scattergram

-2.81 -13.36 7.74
1.04 0.92 1.16 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L -50 0 50 100 150 200 250 300 350 400

GF-AAS, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
0
1.28
0.5285

1.28
0.5285 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

28 1071.00 38.25
28 1248.00 44.57
28 1251.00 44.68 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: MethodAPPENDIX 76 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 19c. Scattergram, box plots, Onesample Sign Test results, and regression coefficients showing copper data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupled plasma–mass spectrometry (ICP–MS) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 20. Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing iron data from the former flame–atomic absorption spectrophotometric (F–AAS) method and inductively coupled plasma–optical emission spectrometry (ICP–OES) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -50

0 50 100 150 200 250 300 350 400ICP-MS, in μg/L

-50 0 50 100 150 200 250 300 350 400 GF-AAS, in μg/L Scattergram

-1.61 -8.17 4.95
1.03 0.94 1.12 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

-50

0 50 100 150 200 250 300 350 400

GF-AAS, in μg/L ICP-MS, in μg/L Box Plot

19
23
0
0.6440 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0 -2000 0 2000 4000 6000 8000 10000 12000 14000 16000ICP-OES, in μg/L

-2000 2000 6000 10000 14000 F-AAS, in μg/L Scattergram

56.02 -111.77 223.81
0.87 0.84 0.90 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. F-AAS, in μg/L

-2000 0 2000 4000 6000 8000 10000 12000 14000 16000

F-AAS, in μg/L ICP-OES, in μg/L Box Plot

30
7
1
0.0002 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0APPENDIX 77 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 21. Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing lead data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupledplasma–mass spectrometry (ICP–MS) for wholewater digests. Concentrations are in micrograms per liter (  g/L). Figure 22a. Scattergrams and regression analyses showing lithium whole-water digest data from inductively coupled plasma–optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former flame–atomic absorption spectrophotometric (F–AAS) method. Concentrations are in micrograms per liter (  g/L). -10

0 10 20 30 40 50 60 70 80ICP-MS, in μg/L

-10 0 10 20 30 40 50 60 70 80 GF-AAS, in μg/L Scattergram

0.12 -1.19 1.43
0.98 0.92 1.04 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

-10

0 10 20 30 40 50 60 70 80

GF-AAS, in μg/L ICP-MS, in μg/L Box Plot

12
19
0
0.2810 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0 -20 0 20 40 60 80 100 120ICP-OES, in μg/L

-20 0 20 40 60 80 100 120 F-AAS, in μg/L Scattergram

1.93 -2.10 5.96
0.90 0.81 1.00 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. F-AAS, in μg/L

-20

0 20 40 60 80 100 120ICP-MS, in μg/L

-20 0 20 40 60 80 100 120 F-AAS, in μg/L Scattergram

-2.49 -7.48 2.50
1.14 1.03 1.26 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. F-AAS, in μg/LAPPENDIX 78 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 22b. Box plots and Kruskal-Wallis Test results showing lithium data from the former flame–atomic absorption spectrophotometric (F– AAS) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP– OES, group 1), and inductively coupled plasma– mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 23. Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing magnesium data from the former flame–atomic absorption spectrophotometric (F– AAS) method and inductively coupled plasma– optical emission spectrometry (ICP–OES) for whole-water digests. Concentrations are in milligrams per liter (mg/L). -20

0 20 40 60 80 100 120

F-AAS, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
7
0.17
0.9191

0.17
0.9191 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

27 1066.00 39.48
27 1128.00 41.78
27 1127.00 41.74 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: Method -10 0 10 20 30 40 50 60ICP-OES, in mg/L

-10 0 10 20 30 40 50 60 F-AAS, in mg/L Scattergram

0.78 0.07 1.49
0.93 0.90 0.96 Coefficient 95% Low er 95% Upper Intercept F-AAS, in mg/L Confidence Intervals ICP-OES, in mg/L vs. F-AAS, in mg/L

19
23
0
0.6440 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0

-10

0 10 20 30 40 50 60

F-AAS, in mg/L ICP-OES, in mg/L Box PlotAPPENDIX 79 Figure 24a. Scattergrams and regression analyses showing manganese whole-water digest data from inductively coupled plasma– optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former flame–atomic absorption spectrophotometric (F–AAS) method. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 24b. Box plots and Kruskal-Wallis Test results showing manganese data from the former flame–atomic absorption spectrophotometric (F–AAS) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP–OES, group 1), and inductively coupled plasma–mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -200

0 200 400 600 800 1000ICP-OES, in μg/L

-200 0 200 400 600 800 1000 F-AAS, in μg/L Scattergram

-3.91 -15.84 8.02
0.99 0.95 1.04 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. F-AAS, in μg/L

-200

0 200 400 600 800 1000ICP-MS, in μg/L

-200 0 200 400 600 800 1000 F-AAS, in μg/L Scattergram

-6.24 -20.07 7.59
0.94 0.89 0.98 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. F-AAS, in μg/L -200 0 200 400 600 800 1000

F-AAS, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
3
0.29
0.8669

0.29
0.8669 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

36 1960.00 54.44
36 1892.00 52.56
36 2034.00 56.50 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: MethodAPPENDIX 80 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 25 . Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing molybdenum data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupled plasma–mass spectrometry (ICP–MS) for whole-water digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 26. Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing nickel data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupledplasma–mass spectrometry (ICP–MS) for wholewater digests. Concentrations are in micrograms per liter (  g/L). -2 0 2 4 6 8 10 12 14 16 18 20ICP-MS, in μg/L

-2 0 2 4 6 8 10 12 14 16 18 20 GF-AAS, in μg/L Scattergram

-0.03 -0.66 0.60
1.05 0.90 1.20 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

-2 0 2 4 6 8 10 12 14 16 18 20

GF-AAS, in μg/L ICP-MS, in μg/L Box Plot

16
12
0
0.5716 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0 -20 0 20 40 60 80 100ICP-MS, in μg/L

-20 0 20 40 60 80 100 GF-AAS, in μg/L Scattergram

0.17 -0.35 0.70
0.87 0.85 0.89 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

-20

0 20 40 60 80 100

GF-AAS, in μg/L ICP-MS, in μg/L Box Plot

24
10
0
0.0243 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0APPENDIX 81 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 27. Scattergram, box plots, Paired t -Test results, and regression coefficients showing selenium data from the former graphite furnace–atomic absorption spectrophotometric (GF–AAS) method and inductively coupledplasma–mass spectrometry (ICP–MS) for wholewater digests. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 28. Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing sodium data from the former flame– atomic absorption spectrophotometric (F–AAS) method and inductively coupled plasma–opticalemission spectrometry (ICP–OES) for wholewater digests. Concentrations are in milligrams per liter (mg/L). -2 0 2 4 6 8ICP-MS, in μg/L

-2 0 2 4 6 8 GF-AAS, in μg/L Scattergram

1.95 -4.05 7.95
0.66 -0.86 2.18 Coefficient 95% Low er 95% Upper Intercept GF-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. GF-AAS, in μg/L

-2 0 2 4 6 8

GF-AAS, in μg/L ICP-MS, in μg/L

Box Plot

-0.90 3 -1.06 0.3670 Mean Diff. DF t-Value P-Value GF-AAS, in μg/L, ICP-MS, ... Paired t-test Hypothesized Difference = 0 -5 0 5 10 15 20 25 30 35 40 45ICP-OES, in mg/L

-5 0 5 10 15 20 25 30 35 40 45 F-AAS, in mg/L Scattergram

-0.10 -0.43 0.23
1.08 1.06 1.10 Coefficient 95% Low er 95% Upper Intercept F-AAS, in mg/L Confidence Intervals ICP-OES, in mg/L vs. F-AAS, in mg/L

-5 0 5 10 15 20 25 30 35 40 45

F-AAS, in mg/L ICP-OES, in mg/L Box Plot

8
25
0
0.0046 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0APPENDIX 82 Figure 29a. Scattergrams and regression analyses showing strontium whole-water digest data from inductively coupled plasma–optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former flame–atomic absorption spectrophotometric (F–AAS) method. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 29b. Box plots and Kruskal-Wallis Test results showing strontium data from the former flame–atomic absorption spectrophotometric (F– AAS) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP– OES, group 1), and inductively coupled plasma– mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -200

0 200 400 600 800 1000 1200ICP-OES, in μg/L

-200 0 200 400 600 800 1000 1200 F-AAS, in μg/L Scattergram

-7.40 -16.59 1.80
1.06 1.04 1.09 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. F-AAS, in μg/L

-200

0 200 400 600 800 1000 1200ICP-MS, in μg/L

-200 0 200 400 600 800 1000 1200 F-AAS, in μg/L Scattergram

-0.71 -8.44 7.03
0.98 0.96 1.00 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. F-AAS, in μg/L -200 0 200 400 600 800 1000 1200

F-AAS, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
2
0.13
0.9369

0.13
0.9369 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

37 2022.00 54.65
37 2122.00 57.35
37 2072.00 56.00 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: MethodAPPENDIX 83 Figure 30a. Scattergrams and regression analyses showing zinc whole-water digest data from inductively coupled plasma–optical emission spectrometry (ICP–OES) and inductively coupled plasma–mass spectrometry (ICP–MS) in relation to the former flame–atomic absorption spectrophotometric (F–AAS) method. Concentrations are in micrograms per liter (  g/L). 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles. DF – Degrees of Freedom H

– Null hypothesis test statistic P-Value – Level of significance

Figure 30b. Box plots and Kruskal-Wallis Test results showing zinc data from the former flame–atomic absorption spectrophotometric (F– AAS) method (group 3), inductively coupled plasma–optical emission spectrometry (ICP– OES, group 1), and inductively coupled plasma– mass spectrometry (ICP–MS, group 2) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -50

0 50 100 150 200 250 300 350 400 450 500ICP-OES, in μg/L

-50 0 50 100 150 200 250 300 350 400 450 500 F-AAS, in μg/L Scattergram

4.55 -12.55 21.65
0.96 0.86 1.06 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-OES, in μg/L vs. F-AAS, in μg/L

-50

0 50 100 150 200 250 300 350 400 450 500ICP-MS, in μg/L

-50 0 50 100 150 200 250 300 350 400 450 500 F-AAS, in μg/L Scattergram

2.67 -5.46 10.80
0.90 0.85 0.95 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. F-AAS, in μg/L -50 0 50 100 150 200 250 300 350 400 450 500

F-AAS, in μg/L ICP-OES, in μg/L ICP-MS, in μg/L Box Plot

2
3
2
0.42
0.8097

0.42
0.8097 DF # Groups
# Ties
H
P-Value
H corrected for ties
Tied P-Value Kruskal-Wallis Test for Data Grouping Variable: Method

17 473.00 27.82
17 418.00 24.59
17 435.00 25.59 Count Sum Ranks Mean Rank
1
2
3 Kruskal-Wallis Rank Info for Data Grouping Variable: MethodAPPENDIX 84 

### EXPLANATION Box plot – horizontal lines, from bottom, represent the 10 th 

### , 25 th 

### , 50 th 

### , 75 th 

### , and 90 th 

### percentiles; data below the 10 th 

### and above 90 th 

### are plotted as circles.

Figure 30c. Scattergram, box plots, One-sample Sign Test results, and regression coefficients showing zinc data from the former flame–atomic absorption spectrophotometric (F–AAS) method and inductively coupled plasma–mass spectrometry (ICP–MS) for whole-water digests. Concentrations are in micrograms per liter (  g/L). -50

0 50 100 150 200 250 300 350 400 450 500ICP-MS, in μg/L

-50 0 50 100 150 200 250 300 350 400 450 500 F-AAS, in μg/L Scattergram

2.24 -2.08 6.55
0.90 0.87 0.93 Coefficient 95% Low er 95% Upper Intercept F-AAS, in μg/L Confidence Intervals ICP-MS, in μg/L vs. F-AAS, in μg/L

-50

0 50 100 150 200 250 300 350 400 450 500

F-AAS, in μg/L ICP-MS, in μg/L Box Plot

13
11
2
0.8388 # Obs. > Hyp. Value # Obs. < Hyp. Value # Obs. = Hyp. Value
P-Value One-Sample Sign Test for Difference Hypothesized Value: 0T a b l e 8. Statis tic a l analy s is of s hor t- ter m ICP–O ES r e s u lts f o r U.S. G eologic a l Sur v ey ’s Standar d Ref e r enc e W a ter Sam p le T 107

[IC P

– OES, in du ctiv ely cou p led plas m a –optical em is s i on s p ectrom e try ; elem en t res u lts are in m i crog r am s p e r liter ex cep t f o r calciu m , m a g n e siu m , silico n , an d so d i u m , w h ich are in m illig ram s p e r liter; MPV
, t h e pu bl i s h e d m o s t probabl e v a l u e; , th e plu s or m i n u s s y m

bol precedes th e F- ps eu dos ig m a in th e MP V colu m n

an d th e s t an dard dev i ation at 1  in th e ex p e rim e n t al co lu m n ; n , eq u a ls th e n u m b e r o f replicates u s ed to calcu late th e m ean ; T
, in dicates th e Stu d en t’ s t

- T est; W
, in d i cates th e W ilco x o n Sig n e d Ran k T e st; p

- v a lu e, lev e l o f sig n i f i can ce; ld , less th an th e m e th o d d e tectio n lim it (see tab l e 1 ) ; <, less th an ]

ICP



### – O ES Elem en t M P V Exp e rim e n t a l

mean , n = 10 T est T est st at ist i c p-v a lue

A l um i num 1 220 45 204 7 T

- 7 .0 < 0

. 0 0 0 1 Ba ri u m 192 11 192.6 0.5 T 3.6 0.0058 B e ry lliu m 11.0 1.1 11.7 0.2 T 9.6 < 0

. 0 0 0 1 Boron 130 21 135 3 T 4.5 0.0015 Ca d m ium 14.3 2.1 13 2 T

- 2 .0 0.073 Calciu m 1 11.7 0.7 11.32 0.02 T

- 4 7 < 0

. 0 0 0 1 Chr o m i um 13.0 2.1 13 3 T 0.47 0.65 C obal t 11.0 1.4 12 2 T 1.6 0.14 C opper 30.0 2.3 29 1 W 5.0 0.025 Iron 52 7 50 2 T

- 2 .8 0.020 L ead 26 4 ld l d ld ld L ith iu m 193 14 191 2 T

- 3 .8 0.0042 M a gne si um 1 2.10 0.13 2.02 0.01 W 0 0.006 M a nga ne se 45 6 45.4 0.4 T 3.2 0.011 Mol y bden u m 15.0 1.9 ld l d ld ld Nick el 28.1 3.9 ld l d ld ld Silico n as SiO 2 7.7 0.5 7.42 0.02 T

- 3 3 < 0

. 0 0 0 1 Silv er 12.3 2.2 11 6 T 8.8 < 0

. 0 0 0 1 S odi u m 1 20.7 1.1 20.6 0.2 W 19 0.42 Stro n tiu m 61 4 60.5 0.2 T

- 6 .8 0.0001 V a na d i um 14.0 2.8 12 1 T

- 4 .1 0.0029 Zi nc 75.8 9.9 74 4 T

- 0 .94 0.37

1 Use d e m issio n w a ve le ngth tha t w a s m o st suita b l e



### .

A PPENDIX 85T a b l e 9. Statis tic a l analy s is of s hor t- ter m ICP–O ES r e s u lts f o r U.S. G eologic a l Sur v ey ’s Standar d Ref e r enc e W a ter Sam p le T 119

[IC P

– OES, in du ctiv ely cou p led plas m a –optical em is s i on s p ectrom e try ; elem en t res u lts are in m i crog r am s p e r liter ex cep t f o r calciu m , m a g n e siu m , silico n , an d so d i u m , w h ich are in m illig ram s p e r liter; MPV
, t h e pu bl i s h e d m o s t probabl e v a l u e; , th e plu s or m i n u s s y m

bol precedes th e F- ps eu dos ig m a in th e MP V colu m n

an d th e s t an dard dev i ation at 1  in th e ex p e rim e n t al co lu m n ; n , eq u a ls th e n u m b e r o f replicates u s ed to calcu late th e m ean ; T
, in dicates th e Stu d en t’ s t

- T est; W
, in d i cates th e W ilco x o n Sig n e d Ran k T e st; p

- v a lu e, lev e l o f sig n i f i can ce; ld , less th an th e m e th o d d e tectio n lim it (see tab l e 1 ) ; <, less th an ]

ICP



### – O ES Elem en t M P V Exp e rim e n t a l

mean , n = 10 T est T est st at ist i c p-v a lue

1 170 30 A l um i num 162 7 T

- 4 .0 0.0026 Ba ri u m 44 3 44.8 0.7 T 3.6 0.0056 B e ry lliu m 13.6 1.7 13.5 0.4 T

- 1 .1 0.31 Boron 28 9 28 4 T

- 0 .17 0.87 Ca d m ium 2.8 0.4 ld l d ld Calciu m 1 11.0 0.8 12.0 0.2 T 15 <0.0001 Chr o m i um 19 2 18 1 T

- 0 .46 0.65 C obal t 5.1 1.0 5 2 T

- 0 .58 0.58 C opper 2.0 1.0 ld l d ld ld Iron 46 7 43 2 T

- 5 .1 0.0007 L ead 6.7 1.2 ld l d ld ld L ith iu m 60 4 59 1 T

- 4 .l 0.0028 M a gne si um 1 3.1 0.2 3.08 0.05 T

- 1 .1 0.31 M a nga ne se 35 3 34.9 0.6 T

- 0 .67 0.52 Mol y bden u m 11.9 2.4 ld l d ld ld Nick el 21.8 2.2 ld l d ld ld Silico n as SiO 2 9.0 0.5 8.8 0.2 T

- 4 .0 0.0033 Silv er 4.0 1.3 ld l d ld ld S odi u m 1 20.3 1.0 21.0 0.3 T 7.1 <0.0001 Stro n tiu m 73 5 73 1 T 0.56 0.59 V a na d i um 3.8 0.9 5 1 T 2.4 0.042 Zi nc 24.8 4.7 26 6 W 40 0.22 ld

1 Use d e m issio n w a ve le ngth tha t w a s m o st suita b l e

.

A PPENDIX 86T a b l e 10. Statis tic a l analy s is of s hor t- ter m ICP–O ES r e s u lts f o r U.S. G eologic a l Sur v ey ’s Standar d Ref e r enc e W a ter Sam p le T 133

[IC P

– OES, in du ctiv ely cou p led plas m a –optical em is s i on s p ectrom e try ; elem en t res u lts are in m i crog r am s p e r liter ex cep t f o r calciu m , m a g n e siu m , silico n , an d so d i u m , w h ich are in m illig ram s p e r liter; MPV
, t h e pu bl i s h e d m o s t probabl e v a l u e; , th e plu s or m i n u s s y m

bol precedes th e F- ps eu dos ig m a in th e MP V colu m n

an d th e s t an dard dev i ation at 1  in th e ex p e rim e n t al co lu m n ; n , eq u a ls th e n u m b e r o f replicates u s ed to calcu late th e m ean ; p- v a lu e, lev e l of s i g n i f i can ce; T
, in dicates th e Stu d en t’ s t

- T est; W
, in d i cates th e W ilco x o n Sig n e d Ran k T e st; ld , less th an th e m e th o d d e tectio n lim it (see tab l e 1 ) ; <, less th an ]

ICP



### – O ES Elem en t M P V Exp e rim e n t a l

mean , n = 10 T est T est st at ist i c p-v a lue

A l um i num 1 52.1 8.1 48 6 T

- 2

. 2 0

. 0 5 2 Ba ri u m 148 9 143.8 0.6 T

- 2 4 < 0

. 0 0 0 1 B e ry lliu m 35.0 2.2 36.2 0.3 T 1 2 < 0

. 0 0 0 1 Boron 297 16 292 5 T

- 3

. 3 0

. 0 0 9 1 Ca d m ium 23.0 2.1 25 2 T 2

. 1 0

. 0 7 7 Calciu m 1 7.0 0.3 6.85 0.02 W 0 0

. 0 0 6 Chr o m i um 38.0 3.2 40 3 T 2

. 0 0

. 0 8 7 C obal t 20.0 1.5 20 6 T 0

. 0 3 0

. 9 7 C opper 85.3 4.5 85 2 T

- 1

. 2 0

. 2 4 Iron 31.4 6.7 31 2 T

- 0

. 3 5 0

. 7 3 L ead 27.8 2.7 ld l d ld ld L ith iu m 51.0 3.5 47.9 0.7 T

- 1 5 < 0

. 0 0 0 1 M a gne si um 1 5.8 0.2 5.56 0.02 W 0 0

. 0 0 6 M a nga ne se 121 7 114.9 0.6 T

- 3 2 < 0

. 0 0 0 1 Mol y bden u m 46.0 4.2 46 12 T

- 0

. 1 0 0

. 9 2 Nick el 27.2 3.1 ld l d ld ld Silico n as SiO 2 10.1 0.7 9.78 0.06 W 0 0

. 0 0 6 Silv er 7.4 0.9 6.4 0.7 T

- 4

. 7 0

. 0 0 1 1 S odi u m 1 29.4 1.2 28.8 0.1 T

- 1 7 < 0

. 0 0 0 1 Stro n tiu m 123 6 119.9 0.3 T

- 3 1 < 0

. 0 0 0 1 V a na d i um 13.0 1.7 10 1 T

- 9

. 4 < 0

. 0 0 0 1 Zi nc 53.0 4.4 44 6 T

- 4

. 4 0

. 0 0 1 7

1 Use d e m issio n w a ve le ngth tha t w a s m o st suita b l e

.

A PPENDIX 87T a b l e 11. Statis tic a l analy s is of s hor t- ter m ICP–O ES r e s u lts f o r U.S. G eologic a l Sur v ey ’s Standar d Ref e r enc e W a ter Sam p le T 135

[IC P

– OES, in du ctiv ely cou p led plas m a –optical em is s i on s p ectrom e try ; elem en t res u lts are in m i crog r am s p e r liter ex cep t f o r calciu m , m a g n e siu m , silico n , an d so d i u m , w h ich are in m illig ram s p e r liter; MPV
, t h e pu bl i s h e d m o s t probabl e v a l u e; , th e plu s or m i n u s s y m

bol precedes th e F- ps eu dos ig m a in th e MP V colu m n

an d th e s t an dard dev i ation at 1  in th e ex p e rim e n t al co lu m n ; n , eq u a ls th e n u m b e r o f replicates u s ed to calcu late th e m ean ; T
, in dicates th e Stu d en t’ s t

- T est; W
, in d i cates th e W ilco x o n Sig n e d Ran k T e st; p

- v a lu e, lev e l o f sig n i f i can ce; ld , less th an th e m e th o d d e tectio n lim it (see tab l e 1 ) ; <, less th an ]

ICP



### – O ES Elem en t M P V Exp e rim e n t a l

mean , n = 10 T est T est st at ist i c p-v a lue

A l um i num 1 10.5 6.8 ld ld ld ld Ba ri u m 67.8 4.3 64.7 0.2 W 0 0.006 B e ry lliu m 59.0 2.6 58.4 0.3 T

- 7

. 4 < 0

. 0 0 0 1 Boron 13.1 11.1 ld l d ld ld Ca d m ium 50.5 3.2 49 2 T

- 1

. 9 0

. 0 9 2 Calciu m 1 10.4 0.6 10.27 0.03 T

- 14 < 0

. 0 0 0 1 Chr o m i um 79.0 5.5 76 1 T

- 5 .7 0.0003 C obal t 40.0 2.6 38 2 T

- 1

. 8 0

. 0 9 7 C opper 62.0 4.2 60 1 T

- 7

. 3 < 0

. 0 0 0 1 Iron 228 11 219 4 T

- 6 .3 0.0001 L ead 103 7 107 16 T 0.80 0

. 4 5 L ith iu m 73.7 5.2 69.4 0.8 T - 17 <0.0001 M a gne si um 1 2.00 0.09 1.97 0.01 W 0 0

. 0 0 6 M a nga ne se 423 20 397 1 T

- 61 < 0

. 0 0 0 1 Mol y bden u m 63.0 5.1 62 11 W 13 0

. 1 5 Nick el 65.6 5.0 59 11 T

- 2

. 1 0

. 0 6 8 Silico n as SiO 2 4.28 0.31 4.09 0.03 W 0 0.006 Silv er 9.8 1.0 11.5 0.8 T 7

. 1 < 0

. 0 0 0 1 S odi u m 1 30.8 1.2 30.2 0.2 T

- 11 < 0

. 0 0 0 1 Stro n tiu m 46.0 2.3 45.5 0.3 T

- 5

. 2 0

. 0 0 0 5 V a na d i um 52.8 3.6 52 1 T

- 1

. 1 0

. 3 0 Zi nc 48.2 4.7 44 4 T

- 3

. 1 0

. 0 1 2

1 Use d e m issio n w a ve le ngth tha t w a s m o st suita b l e

.

A PPENDIX 88T a b l e 12. Statis tic a l analy s is of long- ter m ICP–MS r e s u lts f o r U.S. G eologic a l Sur v ey ’s Standar d Ref e r enc e W a ter Sam p le T 107

[ICP

– MS, in d u ctiv ely co u p led p l asm a

– m ass sp ectro m e try ; elem en t resu lts are in m i cro g ram s p e r liter; MPV
, t h e pu bl i s h e d m o s t probabl e v a l u e; , th e plu s or m i n u s s y m

bol precedes th e F- ps eu dos ig m a in th e MP V colu m n

an d th e s t an dard dev i ation at 1  in th e ex p e rim e n t al co lu m n ; n , eq u a ls th e n u m b e r o f replicates u s ed to calcu late th e m ean ; T
, in dicates th e Stu d en t’ s t

- T est; W
, in d i cates th e W ilco x o n Sig n e d Ran k T e st; p

- v a lu e, lev e l o f sig n i f i can ce; <, less th an ]

ICP



### – MS Elem en t M P V Exp e rim e n t a l

mean , n = 10 T est T est st at ist i c p-v a lue

A l um i num 220 45 237 8 T 6

. 4 0

. 0 0 0 1 A n tim o n y 10.1 2.5 9.8 0.3 T

- 3

. 1 0

. 0 1 3 Ba ri u m 192 11 197 6 W 5 0 0

. 0 2 5 B e ry lliu m 11.0 1.1 13.2 1.4 T 5

. 0 0

. 0 0 0 7 Boron 130 21 158 14 T 6

. 0 0

. 0 0 0 2 Ca d m ium 14.3 2.1 14.2 0.3 T

- 0

. 6 7 0

. 5 2 Chr o m i um 13.0 2.1 16 2 W 5 5 0

. 0 0 6 C obal t 11.0 1.4 11.8 0.4 W 5 5 0

. 0 0 6 C opper 30.0 2.3 30.0 1.8 T 0.07 0

. 9 4 L ead 26 4 27.9 0.4 T 1 4 < 0

. 0 0 0 1 L ith iu m 193 14 220 20 T 4

. 2 0

. 0 0 2 5 M a nga ne se 45 6 48.8 0.6 T 2 1 < 0

. 0 0 0 1 Mol y bden u m 15.0 1.9 15.5 0.5 T 3.4 0

. 0 0 7 5 Nick el 28.1 3.9 28.0 1.4 T

- 0

. 2 3 0

. 8 2 Se l e ni um 11.0 1.9 11.4 1.3 T 0

. 9 9 0

. 3 5 Silv er 12.3 2.2 11.1 0.3 T

- 1 1 < 0

. 0 0 0 1 Stro n tiu m 61 4 61.1 1.7 T 0

. 1 8 0

. 8 6 Zi nc 75.8 9.9 82 4 T 4.3 0

. 0 0 2 0

A PPENDIX 89T a b l e 13. Statis tic a l analy s is of long- ter m ICP–MS r e s u lts f o r U.S. G eologic a l Sur v ey ’s Standar d Ref e r enc e W a ter Sam p le T 119

[ICP

– MS, in d u ctiv ely co u p led p l asm a

– m ass sp ectro m e try ; elem en t resu lts are in m i cro g ram s p e r liter; MPV
, t h e pu bl i s h e d m o s t probabl e v a l u e; , th e plu s or m i n u s s y m

bol precedes th e F- ps eu dos ig m a in th e MP V colu m n

an d th e s t an dard dev i ation at 1  in th e ex p e rim e n t al co lu m n ; n , eq u a ls th e n u m b e r o f replicates u s ed to calcu late th e m ean ; T
, in dicates th e Stu d en t’ s t

- T est; W
, in d i cates th e W ilco x o n Sig n e d Ra nk T e st ; p

- va l u e , l e ve l o f si gni fi c a n c e ]

ICP



### – MS Elem en t M P V Exp e rim e n t a l

mean , n = 10 T est T est st at ist i c p-v a lue

A l um i num 170 30 174 4 T 2

. 0 0

. 0 7 6 A n tim o n y 8.6 1.5 8.7 0.2 T 1

. 0 0

. 3 4 Ba ri u m 44 3 43.2 1.1 T

- 2

. 4 0

. 0 4 0 B e ry lliu m 13.6 1.7 14.7 1.0 T 3

. 4 0

. 0 0 7 4 Boron 28 9 34 10 T 5

. 1 0

. 0 0 0 6 Ca d m ium 2.8 0.4 2.8 0.1 W 4 6 0

. 0 6 7 Chr o m i um 19 2 19 2 W 2 4 0

. 7 6 C obal t 5.1 1.0 5.2 0.1 T 1

. 5 0

. 1 7 C opper 2.0 1.0 2.2 0.1 T 5

. 6 0

. 0 0 0 3 L ead 6.7 1.2 7.2 0.1 T 1 3 < 0

. 0 0 0 1 L ith iu m 60 4 63 4 T 2

. 1 8 0

. 0 5 7 M a nga ne se 35 3 34.9 0.4 T

- 0

. 6 1 0

. 5 5 Mol y bden u m 11.9 2.4 12.2 0.3 T 2

. 6 0

. 0 2 9 Nick el 21.8 2.2 21.3 0.7 T

- 2

. 1 0

. 0 6 6 Se l e ni um 9.8 1.3 9.8 1.3 T

- 0

. 0 7 0

. 9 5 Silv er 4.0 1.3 2.6 1.0 T

- 4

. 5 0

. 0 0 1 5 Stro n tiu m 73 5 71 2 T

- 2

. 8 0

. 0 2 1 Zi nc 24.8 4.7 24.4 0.8 T

- 1

. 6 0

. 1 4

A PPENDIX 90T a b l e 14. Statis tic a l analy s is of long- ter m ICP–MS r e s u lts f o r U.S. G eologic a l Sur v ey ’s Standar d Ref e r enc e W a ter Sam p le T 133

[ICP

– MS, in d u ctiv ely co u p led p l asm a

– m ass sp ectro m e try ; elem en t resu lts are in m i cro g ram s p e r liter; MPV
, t h e pu bl i s h e d m o s t probabl e v a l u e; , th e plu s or m i n u s s y m

bol precedes th e F- ps eu dos ig m a in th e MP V colu m n

an d th e s t an dard dev i ation at 1  in th e ex p e rim e n t al co lu m n ; n , eq u a ls th e n u m b e r o f replicates u s ed to calcu late th e m ean ; T
, in dicates th e Stu d en t’ s t

- T est; W
, in d i cates th e W ilco x o n Sig n e d Ra nk T e st ; p

- va l u e , l e ve l o f si gni fi c a n c e ]

ICP



### – MS Elem en t M P V Exp e rim e n t a l

mean , n = 10 T est T est st at ist i c p-v a lue

A l um i num 52.1 8.1 51.6 1.8 T

- 0 .79 0

. 4 5 A n tim o n y 14.4 2.4 14.5 0.5 T 0.39 0

. 7 1 Ba ri u m 148 9 151 4 T 2.2 0

. 0 5 1 B e ry lliu m 35.0 2.2 36.4 1.1 T 4.1 0

. 0 0 2 7 Boron 297 16 309 11 T 3.5 0

. 0 0 6 7 Ca d m ium 23.0 2.1 22.5 0.5 T

- 3 .0 0

. 0 1 6 Chr o m i um 38.0 3.2 37.0 0.9 T

- 3 .4 0

. 0 0 7 6 C obal t 20.0 1.5 20.2 0.6 T 1.4 0

. 2 1 C opper 85.3 4.5 84 3 W 18 0

. 3 6 L ead 27.8 2.7 28.7 0.6 T 4.3 0

. 0 0 2 1 L ith iu m 51.0 3.5 51.6 1.8 T 1.01 0

. 3 4 M a nga ne se 121 7 120 4 W 28 1

. 0 Mol y bden u m 46.0 4.2 47.0 1.2 T 2.7 0

. 0 2 6 Nick el 27.2 3.1 26.7 0.7 T

- 2 .1 0

. 0 6 4 Se l e ni um 21.4 3.7 20.8 1.4 T

- 1 .5 0

. 1 6 Silv er 7.4 0.9 7.5 0.2 T 1.8 0

. 1 0 Stro n tiu m 123 6 124 3 T 0.99 0

. 3 5 Zi nc 53.0 4.4 52 2 T

- 1 .2 0

. 2 6

A PPENDIX 91Table 15.Statistical analysisoflong-termICP–OES and ICP–MS resultsforU.S. Geological Survey’sStandard Reference WaterSample WW-1[ICP–OES, inductivelycoupled plasma–optical emissionspectrometry;ICP–MS, inductivelycoupled plasma–massspectrometry;elementresults are inmicrogramsper liter except for calcium, magnesium, silicon, andsodium, whichare inmilligramsper liter; MPV, the publishedmostprobable value;, theplusor minussymbol precedesthe F-pseudosigmainthe MPV columnand the standard deviationat 1inthe experimental columns;n,equalsthe number ofreplicatesused to calculate the mean; T,indicatesthe Student’s t-Test; W,indicates the WilcoxonSignedRankTest; nd, elementwas not determinedbyspecific analytical method; ld, lessthanthe method detectionlimit (see table 1); p-value, level ofsignificance; gl, greaterthanupper calibrationlimit oftheanalytical method; <, lessthan]ICP–OESICP–MSElementMPVExperimentalmean, n=20TestTeststatisticp-valueExperimentalmean, n=20TestTeststatisticp-valueAluminum17,0805,7008,500200W210<0.0001glglglglAntimony3.62.5ndndndnd2.60.2T14<0.0001Barium156341613T8.0<0.00011684T14<0.0001Beryllium9.00.98.20.2T-8.8<0.00018.90.9T-0.510.61Boron3138162T-11<0.0001183T-18<0.0001Cadmium6.11.14.60.6T-3.30.00376.10.2T0.740.47Calcium117.91.317.90.2T0.290.78ndndndndChromium22519.90.4T-4.50.0003266T3.10.0065Cobalt213.52.7ldldldld13.30.6T-1.70.10Copper286241T-7.9<0.000126.80.9T-6.6<0.0001Iron14,0004,00013,280170T-19<0.0001ndndndndLead25.85.1ldldldld25.00.4T-9.6<0.0001Lithium19.04.415.60.2W0<0.0001182W760.29Magnesium1717.10.1T2.20.040ndndndndManganese595545939T-1.20.2656040W140.001Table 15.Statistical analysisoflong-termICP–OES and ICP–MS resultsforU.S. Geological Survey’sStandard Reference WaterSample WW-1—ContinuedICP–OESICP–MSElementMPVExperimentalmean, n=20TestTeststatisticp-valueExperimentalmean, n=20TestTeststatisticp-valueMolybdenum4.91.8ldldldld3.30.1T-59<0.0001Nickel24.07.9ldldldld22.60.7T-8.9<0.0001Selenium5.52.1ndndndnd6.30.8T4.40.0003Siliconas SiO2311540.31.2W210<0.0001ndndndndSilver2.31.8ldldldld1.600.06T-49<0.0001Sodium119.71.719.90.3T4.50.0002ndndndndStrontium847851T4.80.000185.81.7T4.70.0002Vanadium24920.70.5W0<0.0001ndndndndZinc8020744W1200.72655T-8.5<0.00011Themost suitableemissionwavelength was usedforICP–OES.2Cobalt result isnot reported becauseironconcentrationexceedscorrectionlimit for ICP–OEST a b l e 16. Analy t ic al var i ability of ICP–O ES and ICP–MS r e s u lts f o r Standar d Ref e r enc e Wa t e r S a m p l e WW- 1

[IC P

– OES, in du ctiv ely cou p led plas m a –optical em issio n sp ectro m e try ; ICP

– MS, in d u ctiv ely

co u p led p l asm a

– m ass sp ectro m e try ; b a sed o n th ree seq u en tial d e term in atio n s o f an aliq u o t o f Stan d a rd Ref e ren ce W a ter Sam p le (SRW S) W W

- 1 in

- b o ttle d i g e st;  g / L
, m i cro g ram p e r liter; %RSD, p e rcen t relativ e stan d a rd d e v i atio n ; n d , n o t d e term in ed ; ld , less th an m e th o d d e tectio n lim it (see tab l e 1 ) ; m g /L , m illig ram p e r liter]

Elemen t Co n cen t r at io n , in  g/L % R S D ICP



### – O ES % R S D ICP



### – MS
A l um i num 1 2 2 0 4 0

. 4 A n t i m on y 3

. 6 n d 3 Bari u m 1 5 6 0

. 1 1 B e ry lliu m 9

. 0 0

. 0 7 2 Boron 3 1 1 0 4 C a dm i u m 6

. 1 5 0 2 C a l c i u m , m g / L 18 0.1 n d C h rom i u m 2 2 5 2 C obal t 1 1 1 2 0 2 C o p p e r 2 8 9 4 Iron 1 4
, 0 0 0 0

. 2 n d L ead 2 1 6 0 2 0 0

. 1 L i t h i u m 1 9 2 2 Mag n e s i u m , m g / L 7.0 0.04 n d Man g a n e s e 5 9 5 0

. 0 5 3 Mol y bden u m 2 6 5 6 2 N i ck el 2 4 l d 0

. 2 S e l e n i u m 5

. 5 n d 2 0 Silico n , m g /L as SiO 2 3 1 0

. 2 n d Silv er 1 1 2 1 0 3 S odi u m , m g / L 20 0.5 n d S t ron t i u m 8 4 0

. 0 5 1 T h alliu m 3 0

. 1 8 n d 6 Uran iu m 3 1

. 0 n d 3 V a n a di u m 2 4 2 n d Z i n c 8 0 8 4

1 R e s u l t s are f o r S R WS T 107 di g e s t

. 2 Es t i m at ed con cen t r at i o n f

o r s p i k ed S R WS T 117 di g e s t

. 3 U n pu

bl i s h e d m ean con cen t r at i o n f

o r WW- 1 di g e s t bas e d on n

u m erou s det e rm i n at i o n s

.

A PPENDIX 94T a b l e 17. Analy t ic al var i ability of ICP–O ES and ICP–MS over an ex tended c onc entr a tion r ange

[IC P

– OES, in du ctiv ely cou p led plas m a –optical em issio n sp ectro m e try ; ICP

– MS, in d u ctiv ely

co u p led p l asm a

– m ass sp ectro m e try ; b a sed o n th ree seq u en tial d e term in atio n s o f an aliq u o t o f
stan d a rd p r ep ared in calib ratio n b l an k so lu tio n ;  g / L
, m i cro g ram p e r liter; m g /L , m illig ram p e r liter; RSD, relativ e stan d a rd d e v i atio n ; <MDL , less th an m e th o d d e tectio n lim it; n a , n o t ap p licab le;

n d , n o t d e term in ed ]

Co n cen t r at io n Percen t RSD P e r c e n t RSD P e r c e n t RSD P e r c e n t RSD (  g/L) ICP– O ES ICP– MS ICP– O ES ICP– MS ICP– O ES ICP– MS ICP– O ES ICP– MS A l u m i n u m A n timony B a r i u m Bery l l i u m 5 <MD L 2 n a 2 0

. 8 5 4 2 12.5 <MD L 0

. 8 n a 0

. 9 1 1 2 1 2 5 2 0 0

. 5 n a 2 0

. 8 2 1 1 5 0 8 0

. 6 n a 0

. 4 0

. 0 8 1 1 0

. 9 1 0 0 3 0

. 2 n a 1 0

. 5 0

. 8 0

. 7 1 2 5 0 5 0

. 5 n a 0

. 5 0

. 4 0

. 9 0

. 5 0

. 7 5 0 0 2 0

. 9 n a 0

. 4 0

. 2 0

. 9 0

. 3 0

. 6 1
, 0 0 0 2 0

. 3 n a n d 0

. 2 2 0

. 2 n d 2
, 5 0 0 0

. 5 n d n a n d 0

. 6 n d 0

. 4 n d Bor o n C a d m i u m Chr o m i u m Coba l t 5 <MD L 1 6 <MD L 1 0 <MD L 3 5 0 1 12.5 <MD L 4 2 0 4 1 0 3 2 0 1 2 5 2 0 2 6 1 1 0 8 1 0 2 5 0 6 2 5 0

. 6 1 0 3 3 1 1 0 0 8 2 6 1 0

. 7 1 4 0

. 7 2 5 0 3 0

. 8 0

. 8 0

. 6 2 0

. 3 2 0

. 2 5 0 0 2 1 1 0

. 9 1 2 0

. 8 0

. 6 1
, 0 0 0 2 n d 0

. 5 n d 0

. 6 n d 0

. 7 n d 2
, 5 0 0 0

. 6 n d 0

. 4 n d 0

. 2 n d 0

. 6 n d C o p p e r L e a d L i t h i u m M a n g a n e s e 5 <MD L 2 0 <MD L 1 <MD L 5 1 0 3 1 2

. 5 3 0 4 <MD L 0

. 4 1 0 2 1 2 2 5 1 2 <MD L 0

. 7 3 1 0

. 8 1 5 0 1 2 <MD L 0

. 7 1 2 0

. 7 1 1 0 0 1 2 6 0 0

. 3 2 1 1 1 2 5 0 2 2 2 0 2 0

. 7 0

. 6 0

. 2 0

. 7 5 0 0 0

. 6 0

. 8 7 0

. 4 0

. 2 2 0

. 4 2 1
, 0 0 0 0

. 5 n d 7 n d 0

. 1 n d 0

. 1 1 2
, 5 0 0 0

. 5 n d 2 n d 0

. 6 n d 0

. 5 n d M o ly b d e n u m N i c k e l Selen i u m Silv e r 5 <MD L 3 <MD L 4 n a 7 0 3 0 1 12.5 <MD L 2 <MD L 4 n a 2 0 1 0 2 25 <MD L 3 <MD L 3 n a 2 0 7 1 5 0 2 0 2 3 1 n a 6 4 n d 1 0 0 8 1 3 0 2 n a 2 2 n d 2 5 0 3 0

. 7 8 2 n a 4 0

. 6 n d 5 0 0 3 0

. 7 2 1 n a 1 0

. 4 n d 1
, 0 0 0 2 n d 3 n d n a n d 0

. 7 n d 2
, 5 0 0 0

. 9 n d 2 n d n a n d n d n d

A PPENDIX 95T a b l e 17. Analy t ic al var i ability of ICP–O ES and ICP–MS over an ex tended c onc entr a tion

r ange—Continued

Co n cen t r at io n Percen t RSD P e r c e n t RSD P e r c e n t RSD P e r c e n t RSD (  g/L) ICP– O ES ICP– MS ICP– O ES ICP– MS ICP– O ES ICP– MS ICP– O ES ICP– MS S t r o n t i u m T h a l l i u m U r a n i u m V a n a d i u m 5 0

. 7 1 n a 1 n a 0

. 3 <MD L na 1 2

. 5 3 0

. 4 n a 2 n a 0

. 4 6 n a 2 5 0

. 7 2 n a 0

. 5 n a 1 1 0 n a 5 0 0

. 4 0

. 8 n a 0

. 6 n a 1 2 n a 1 0 0 0

. 8 1 n a 0

. 6 n a 1 2 n a 2 5 0 0

. 4 0

. 8 n a 2 n a 1 0

. 4 n a 5 0 0 0

. 2 0

. 8 n a 0

. 0 8 n a 0

. 4 0

. 9 n a 1
, 0 0 0 0

. 2 n d n a n d n a n d 0

. 4 n a 2
, 5 0 0 0

. 6 n d n a n d n a n d 0

. 3 n a Zinc 5 <MD L 3 12.5 <MD L 0

. 4 2 5 4 2 5 0 1 0 4 1 0 0 2 0 0

. 8 2 5 0 1 0 1 5 0 0 2 0

. 9 1
, 0 0 0 3 0

. 4 2
, 5 0 0 0

. 3 n d

Co n cen t r at io n (  g/L) Calcium Ir on M a gne s i um S i l i c o n a s SiO 2 0

. 0 1 5 n a 0

. 7 n a 5 n a <MD L na 0

. 0 5 0

. 8 n a 4 n a 0

. 8 n a <MD L na 0

. 1 0

. 3 n a 4 n a 0

. 7 n a 2 0 n a 0

. 5 0

. 3 n a 0

. 2 n a 0

. 3 n a 5 n a 1 0

. 3 n a 0

. 1 n a 0

. 5 n a 3 n a 5 0

. 2 n a 0

. 5 n a 0

. 2 n a 2 n a 1 0 0

. 7 n a 0

. 7 n a 0

. 8 n a 1 n a 5 0 0

. 6 n a 0

. 8 n a 0

. 4 n a 2 n a 1 0 0 0

. 4 n a 0

. 4 n a 0

. 2 n a 1 n a S odium 0.01 <MD L n a 0.05 <MD L n a 0

. 1 6 n a 0

. 5 4 n a 1 0

. 3 n a 5 0

. 7 n a 1 0 0

. 8 n a 5 0 0

. 0 9 n a 1 0 0 0

. 5 n a

A PPENDIX 96Table 18.Spike recovery results for whole-water digests[S/cm, microsiemens per centimeter at 25C;g/L, microgram per liter; % rec, percent spike recovery;ICP–OES, inductively coupled plasma–optical emissionspectrometry; ICP–MS, inductively coupled plasma–mass spectrometry; nd, not determined]Specificconductance,S/cm1Spike,g/L% recICP–OESSpike,g/L% recICP–MSSpike,g/L% recICP–OESSpike,g/L% recICP–MSSpike,g/L% recICP–OESSpike,g/L% recICP–MSAluminumAntimonyBarium1033409834099ndnd1098509952922307109572096ndnd101006110064965191,520941,52099ndnd1010040101409568361097660105ndnd101006110076931,6001301101782ndnd101021801002201061,900130843092ndnd109881998296Average% rec9696nd10010096BerylliumBoronCadmium10315920.4120819210296501050.88123015920.412012098140103501200.88451915924.0120101985010950980.89468315920.41201011049212050971.3961,60015910.493101951028750990.8821,90015880.410425010328096501090.889Average% rec911139810210588ChromiumCobaltCopper103501105.08071951.39850967.610723050979.67471991.39350978.89451950997.89916099150985010830106683501041597711021.010550110111031,60050105828071941.179501058.0871,90050101129171980.69250976.292Average% rec10387989410298Table 18.Spike recovery results for whole-water digests—ContinuedSpecificconductance,S/cm1Spike,g/L% recICP–OESSpike,g/L% recICP–MSSpike,g/L% recICP–OESSpike,g/L% recICP–MSSpike,g/L% recICP–OESSpike,g/L% recICP–MSIronLeadLithium1031,010101ndnd5051061.3101711036.410323018297ndnd5051053.29971102241085194,848101ndnd505985.4977110042120683859102ndnd5051071.3977199221201,6001,616104ndnd505980.9102719810821,900303105ndnd505971.099719688102Average% rec102nd10299100106ManganeseMolybdenumNickel10332010130093303965.0993031002.6110230202100200893031015.0893031022.4965194,85099ndnd3031015.09930310824098683711017092303996.010230727.8951,600209813743031056.08730310924741,900404103340873031005.089303992.490Average% rec10087100949894SeleniumSilverStrontium103ndnd209426108108712010312097230ndnd209026102109112010412092519ndnd209526106108913010414094683ndnd171002610710891,6201031,800911,600ndnd20932610210861,2101041,300901,900ndnd207826106108266010570088Average% recnd921058710492Table 18.Spike recovery results for whole-water digests—ContinuedSpecificconductance,S/cm1Spike,g/L% recICP–OESSpike,g/L% recICP–MSSpike,g/L% recICP–OESSpike,g/L% recICP–MSSpike,g/L% recICP–OESSpike,g/L% recICP–MSThalliumUraniumVanadium103ndnd2.094ndnd4.0904096ndnd230ndnd2.091ndnd4.01024092ndnd519ndnd2.089ndnd4.09640100ndnd683ndnd2.093ndnd3.010240100ndnd1,600ndnd2.098ndnd6.8964099ndnd1,900ndnd2.095ndnd4.49840103ndndAverage% recnd93nd9798ndZinc1032021051097230202961792519760102720102683505105101001,6001,9002021007.2642021126.292Average% rec103911Specific conductance of sample before acidification and in-bottle digestion.T a b l e 19. Chem ic al c har ac ter i s t ic s of natur al w hole- w a ter s a m p les

[< MDL
, les s th an th e m e th od detection lim it; IC P

– OES, in du ctiv ely cou p led plas m a –optical em is s i on

s p ectrom e try ; IC P

– MS, in du ctiv ely cou p led plas m a –m as s s p ectrom e try ;  g / L
, m i cro g ram p e r liter; m g /L , m illig ram p e r liter;  S/cm , m i cros iem e n s per cen tim eter at 25 C; n d , n o t d e term in ed b y m e th o d ; n o , n o f o rm er m e th o d is av ailab l e; —, n o t ap p licab le]

Elemen t o r
c ons titue n t mum 25t h pe r cen t ile Me d i a n 75t h pe r cen t ile M axiFr a c t ion of samp l es < M D L f o r the for m e r
me thod Fr a c t ion of samp l es < M D L f o r the ICP

–

O ES

me thod Fr a c t ion of samp l es < M D L f o r the ICP

– MS

me thod
A l um i num , i n  g/ L 6 0 3 2 0 8 5 0 2 0
, 4 0 0 1/ 4 3 1/ 4 3 0/ 4 3 A n tim o n y , in  g/ L 0

. 8 1 5 6 31/ 4 3 n d 31/ 4 3 Ba ri u m , i n  g/ L 1 1 0 1 4 0 1 8 0 6 6 0 23/ 4 3 0/ 4 3 0/ 4 3
B e ry lliu m , in  g/ L 0

. 9 2 7/ 4 3

n d

37/ 43

7 4 20 0/ 43 24 15/ 43 2 1 2 43/ 4 3 28/ 4 3 21/ 4 3 Boron
, i n  g/ L 1 9 2 2 3 6 8 3 6/ 4 3 2/ 4 3 Cad m iu m , in  g/ L 0

. 2 0

. 4 0

. 7 6 14/ 43 42/ 43 4/ 43 C a l c i u m , i n m g / L 9 27 47 67 10/ 43 0/ 43 Chr o m i um , in  g/ L 6 1 1 2 0 1 6 0 3/ 4 3 28/ 4 3 17/ 4 3 Co b a lt, in  g/ L 0

. 8 3 7 8 4 12/ 43 0/ 43 C opper, i n  g/ L 2 6 1 7 3 6 0 1/ 4 3 15/ 4 3 0/ 4 3 Iron
, in  g/ L 3 8 0 1
, 4 0 0 4
, 2 0 0 1 4
, 0 0 0 1/ 43 1/ 43 n d
L ead, in  g/ L 2 4 2 0 9/ 4 3 39/ 4 3 0/ 4 3
L ith iu m , in  g/ L 1 0 4 0 1 6 0 15/ 43 11/ 43 0/ 43 Mag n e s i u m , i n m g / L 3 11 22 50 0/ 43 n d M a nga ne se , i n  g/ L 7 6 2 6 0 8 2 0 1/ 43 1/ 43 0/ 43 Mo ly b d e n u m , in  g/ L 1 2 4 1 4 43/ 43 11/ 43 Nick el, in  g/ L 2 4 1 0 9 5 7/ 4 3 36/ 4 3 2/ 4 3 Se l e ni um , i n  g/ L L i m i t e d dat a s e t 40/ 43 n d 39/ 43 Silico n , in m g SiO 2 / L 9 1 7 3 0 9 0 n o 0/ 4 3 n d Silv er, in  g/ L L i m i t e d dat a s e t 42/ 43 43/ 43 42/ 43 S odi u m , i n m g / L 3 10 18 40 0/ 43 0/ 43 n d Stro n tiu m , in  g/ L 6 0 2 3 0 4 0 0 1
, 0 0 0 0/ 43 0/ 43 0/ 43
T h alliu m , in  g/ L L i m i t e d dat a s e t n o n d 41/ 43 Uran iu m , in  g/ L 0

. 5 1 2 1 6 n o n d 5/ 4 3 V a na d i um , i n  g/ L 8 9 2 0 6 0 n o 23/ 4 3 n d Zi nc , i n  g/ L 1 4 3 8 1 2 0 4 0 0 19/ 43 24/ 43 1/ 43

A l k a l i n i t y , i n m g / L 43 68 130 410

— — — C h l o ri de, i n m g / L 6 12 36 9,500

— — — C o n d ., in  S/cm 1 1 7 0 3 0 0 6 2 0 2 5
, 4 0 0

— — — S u l f at e, i n m g / L 5 28 60 1,600

— — —

1 Specif i c con d u c tan ce (C on d.) in m i cros iem e n s per cen tim eter (  S/cm ) o f th e w h o l e- w a ter sam p le p r io r to d i ge st i o n.

A PPEN D I X 100T a b l e 20. Statis tic a l analy s is s u m m a r y of ICP–O ES and ICP–MS r e s u lts f o r natur al w holew a ter diges ts

[IC P

– OES, in du ctiv ely cou p led plas m a –optical em i ssio n sp ectro m e try ; ICP

– MS, in d u ctiv ely co u p led plas m a –m as s s p ectrom e try ; DC P

– A E S, direct cu rre n t plas m a –atom i c em is s i on s p ectrom e try ; GF– A A S , s t abilized tem p eratu r e g r aph ite f u rn ace–atom ic abs o rption s p ectroph otom etry ; F–A A S , f l am e– at om i c abs o rpt i o n s p ect roph ot om et ry ; n , n u m ber of s a m p le resu lts u s ed in th e statistical an aly s is; id
, in su f f i cien t d a ta; n d , n o t d e term in ed b y an an aly tical m e th o d ; —, n o d a ta; <, less th an ]

Elemen t For me r me thod t o ICP–O ES t o ICP–M S For me r me thod t o ICP–O ES For me r me thod to ICP–M S For me r
me thod

n Kru skalW a llis p-v a lue n One

samp l e S i gn T e s t

p-v a lue n O n e- samp l e S i gn T e s t

p-v a lue

A l u m i n u m D C P–A E S 2 5 0

. 9 7 5 0

— R e du n d an t

— R e du n d an t A n tim o n y 1 G F –A A S

— In appropri a t e

— n d 9 0

. 3 0 6 1 Bari u m F

– A A S 2 0 0

. 3 7 4 9

— R e du n d an t

— R e du n d an t B e ry lliu m F

– A A S

— id

— id

— id Boron D C P–A E S 2 8 0

. 0 0 2 1 3 6 0

. 0 2 8 8 2 8 0

. 0 0 0 9 C a dm i u m G F –A A S

— i d

— i d 2 7 F

– A A S In appropri a t e 4 2 n d

0.0033

Iron 0

. 0 5 2 2 C a l c i u m

— < 0

. 0 0 0 1

— C h rom i u m G F –A A S 1 5 0

. 0 0 7 8 1 5 < 0

. 0 0 0 1 2 6 < 0

. 0 0 0 1 C obal t G F –A A S 6 0

. 0 7 2 8

— R e du n d an t 3 1 C o p p e r G F –A A S 2 8 0

. 5 2 8 5

— R e du n d an t 4 2 0

. 6 4 4 0 F

– A A S

— In appropri a t e 3 8 0

. 0 0 0 2

— n d L e a d G F –A A S

— i d

— i d 3 1 0

. 2 8 1 0 L i t h i u m F

– A A S 2 7 0

. 9 1 9 1

— R e du n d an t

— R e du n d an t Mag n e s i u m F

– A A S

— In appropri a t e 4 2 0

. 6 4 4 0

— n d Man g a n e s e F

– A A S 3 6 0

. 8 6 6 9

— R e du n d an t

— R e du n d an t Mol y bden u m G F –A A S

— i d

— i d 2 8 0

. 5 7 1 6 N i ck el G F –A A S

— i d

— i d 3 4 0

. 0 2 4 3 Se l e ni um 1 G F –A A S

— In appropri a t e

— n d 4 0

. 3 6 7 0 Silico n as SiO 2 N o n e

— In ap p r o p r iate

— id

— n d Silv e r G F

– A A S

— id

— id

— id S odi u m G F –A A S

— In appropri a t e 3 3 0

. 0 0 4 6

— n d S t ron t i u m G F –A A S 3 7 0

. 9 3 6 9

— R e du n d an t

— R e du n d an t T h alliu m N o n e

— In ap p r o p r iate

— n d

— id Uran iu m N o n e

— In ap p r o p r iate

— n d

— id V a n a di u m N o n e

— In appropri a t e

— i d

— n d Z i n c F

– A A S 1 7 0

. 8 0 9 7

— R e du n d an t 2 6 0

. 8 3 8 8

1 T h e paired Stu d en t t

- t est w a s u s ed o n a lim ited d a ta set.

A PPENDIX 101