415.3 - 1

METHOD 415.3 DETERMINATION OF TOTAL ORGANIC CARBON AND SPECIF IC UV ABSOR BANCE AT 25 4 nm IN SOU RCE WATER AND DRINKING W

ATER

Revision 1. 1 February, 200 5

B. B. Potter, USEPA, Office of Researc h and Development, National Exposure Research L aboratory J. C. Wimsatt, The Nationa l Council O n The Aging, Sen ior Envir onmental Employ ment Prog

ram

NATI ONAL

EXPOSURE RE SEARCH L ABORATO RY OFFICE OF

RESEARCH AND DEVELOPMENT U.S. ENVI

RONMENTA

L PROTECTI ON AGENC Y CINCI NNATI, OHIO 45268415.3 - 2 METHOD 415.3 DETERMI

NATI ON OF TO TAL O RGANI C CARBON A ND SPECI

FIC U V ABSORB ANCE AT 254 nm IN SOURCE WATER AND DRI NKING WATER

1.0 SCOPE AN

D APP LICATION
1.1 This method provides procedures for the determination of total org anic carbon (TOC), dissolved organic carbon (DOC), and UV absorption at 254 nm (UVA) in source waters and drinking waters. The DO C and UVA determinations are used in the calculation of the Specific UV Absorbance ( SUVA). For TOC and DOC analysis, the sample is acidified and the inorganic car bon (IC) is removed prior to ana lysis for organic carbon (OC) content using a TOC instrument system. The measur ements of TOC and DO C are ba sed on ca libration with potas sium hy

droge n phthala te (KHP) standards. This method is not intended for use in the analy sis of treated or untreated industrial wastewater discharges as those wastewater samples may damage or contaminate the instrument system(s).
1.2 The thre e (3) da

y, p ooled organic ca

rbon dete ction limit ( OCD L) is based on the detection limit (DL) calculation. 1 It is a statistical determination of precision, and may be below the

level of quantitation. The determination of OCDL is depe ndent on the analytica

l instrument system’s precision, the purity of laboratory

reagent water (LRW), and the skill of the analy st. Different TOC instrument systems have produced significantly

different OCDLs that range between 0.02 and 0.12 mg/L OC for both T OC and DO C measure ments. Exam

ples of th ese data

can be se en in Section 17, Table 17.1. It should be noted that backg round levels of OC contamination are problematic. The minimum reporting level (MRL ) for TOC and DOC will depend on the laboratory ’s ability to control backg round levels (Sect. 4).
2.0 SUMMARY

OF METHOD
2.1 In both TOC and DOC determinations, org anic carbon in the water sample is oxidized to produc e carbon dioxide (CO 2 ), which is then measured by a detection system. There are two different appr oaches for the oxidation of organic carbon in wa ter samples to carbon dioxide gas: (a) combustion in an oxidizing gas and (b) UV promoted or heat cataly

zed chemical oxidation with a persulfate solution. Carbon dioxide, wh

ich is rel eased f

rom the oxidized sample , is detected by a conductivity detector or by

a nondispersive infrared (NDI R) detector. Instruments using a ny combination of the above technologies may be used in this method.
2.2 Settleable solids and floating matter may cause plugging of va

lves, tubing, and the injection needle and/or injection port. The TOC procedure a llows the removal of settleable solids and floating matter. The suspended matter is consider ed part of the415.3 - 3 sample. The resulting water sample is then considere d a close approximation of the origina l whole wa

ter sampl e for the

purpose o f TOC mea suremen t. 2.3 The DOC procedure requires that the sample be passed through a 0.45-μm filter prior to analysis to remove par ticulate OC from the sample.
2.4 The TOC and DOC procedures require that a ll IC be removed from the sample be fore the sample

is analy zed for or ganic c arbon co

ntent. I f the I C is not comp letely removed, significant error will occur. The sam pl e, w hi ch i s t hen fre e fr om IC interfe rence, is injecte d into a TO C instrume nt sy stem. The

organ ic carb on is oxidized to CO 2, which is released from the sample, detected, a nd reported as mg/L

or ppm TOC or D OC.
2.5 The UVA procedure requires tha t the sample be passed through a 0.45-μm filter and transferred to a quartz cell. I t is then placed in a spectrophotometer to measure the UV absorbance at 254 nm and reported in cm -1

. 2.6 The SUVA

calcula tion requ ires both the DOC a

nd UVA me asureme

nt. The SUV

A is calculated by

dividing the UV absorbance of the sample (in cm -1 ) by the DOC of the sample (in mg/L) and then multiply ing by 100 c

m/M. SUVA is reported in units of L/mg-M. The formula f

or the SUVA may be

found in Section 12.2.
3.0 DEFINITIONS AND TERMS

NOTE: To assist the reader, a table of acronyms can be found in Section 3.20.
3.1 ANAL

YSIS B ATCH - A se

t of sample s prepar

ed and a naly zed on the s ame instrument during a 24-hour period. For a TOC/DOC ana lysis batch, the set may contain: calibra

tion stand ards, la borator y r eage nt blank a nd/or filt er blanks, field blank, field samples, laboratory fortified matrix sample, field duplicate sample, and continuing calibration check standards. For a UVA analy sis batch, the set may contain: filter blanks, field samples, field blank, field duplicate sample, and spectro photomete

r check solutions w

ith assoc iated bla

nk. An ana

lys is batch is limited to 20 field samples. QC samples are not counted towards the 20 sample limit. QC requirements are summarized in Table 17.6.
3.2 BLANKS - Prepar ed from a volume of LRW (Se ct. 3.9) a nd used a s needed

to fulfill quality assuran ce requ irements and to moni

tor the a naly tical sy stem. 3.2.1 CALI

BRATI ON BL

ANK (CB ) - The c alibrati on blank is a volume o f LRW that is treated with the same reagents used in the pre paration of the calibration standards. The CB is a “zero standard” and is used to ca librate the TOC instrument. The CB is made at the same time as the calibration standards and stored a long with and unde r the same

condition s as the c alibrati on standa rds. The CB is also used to monitor increases in organic bac kground found in the415.3 - 4 calibration standards over time by analyzing it as a sa

mple and comparing the results with initial analysis of the CB.
3.2.2 FIELD REAGENT BL ANK (FR B) - A vo lume, equ

ivalent to that which is collected at a sample site, of L RW is placed in a sample bottle or vial. A second e mpty sample bo ttle or via

l accomp anies the

LRW sam

ple conta iner to the sample

site. At th e sample

site, the L

RW is transf

erred i nto the em

pty bottle or v

ial which then bec omes the F RB. The F RB is trea ted as a s ample in all respects including shipment from the sampling site, exposure to the sampling site conditions, storage, preservation, and a ll analytical proce dures. The purpose of the FRB is to determine if the TOC, DOC, and UV A measurements of the samples collected in the field are free from interference s or contamination as a result of the sample collection procedure and/or transpor t of the sa mple(s) t o the laboratory . The FRB is optiona l and is usually used when the la

boratory suspec

ts a problem in sample collection and handl ing.
3.2.3 FILTER BLANK (F B) - The FB is an aliquot of L RW that is filtered and analyzed using the

same procedures as field samples undergoing DOC and UVA determinations. For DOC and UVA analy ses, the FB serves as the L RB. The FB will give an indication of overa ll contribution of organic carbon contamination from laboratory sources such as the LRW itself, labware cleaning procedures, re agents, the filter apparatus, filter, and instrument system(s).
3.2.4 LAB ORATORY RE AGENT B LANK

(LRB ) - A volume of L

RW that is prepar ed with ea

ch sample set and is treated exactly as a TOC sa

mple including exposure to all glassware, plasticware , equipment, and reagents that are use d with othe

r samples . The L

RB is used

to deter mine if or ganic contamination or o ther inte rfere nces ar e prese nt in the la

borator y e nvironme nt, reagents, apparatus, or proc edures. The LRB must be a cidified and sparged following the same procedure as is used to pre pare the TOC sample(s).
3.3 CALI

BRATION SOL

UTIONS - Calibration should be perfor med according to the manufacturer’s operation manual. The f ollowing solutions are used to calibrate the TOC instrument system for TOC or DOC dete rminations (calibration solutions are not used f or UVA de

terminat ion):
3.3.1 ORGANIC CARBON PRI MARY DIL

UTION STANDARD (OC-PDS) - A concen trated so lution con

taining potassium h

ydr ogen ph thalate ( KHP) in LRW water that is prepared in the labor atory or is an a ssayed KHP standar d solution purchased from a commercial source. The O C-PDS is used for the preparation of organic ca

rbon calibration standards (OC-CAL), continuing415.3 - 5 calibration check standards (CCC), and laboratory fortified matrix samples (LFM).
3.3.2 ORGANIC CARBON CAL IBRATI ON STANDARD (OC-CAL) - A solution prepared from the OC-PDS and diluted with LRW to various conc entrations. The OC-CA

L solu tions are used to ca

librate t he instru ment resp onse with respect to organic carbon c oncentration.
3.3.3 CONTINUI

NG CALI

BRATION CHECK (CCC) - An OC-CAL solution which is analyzed per

iodically to verify

the accuracy

of the existing calibration of the instrument (Sect. 10.3).
3.4 DISSOLV

ED ORGANIC CARBON (DO C) - Organic matter, contained in a wa ter sample that is soluble and/or colloidal, that can pass through a 0.45-μm filter.
3.5 FIELD DU

PLI CATES (FD 1 and FD 2) - Two s eparat e sample s collec ted at the same time and place under identical circumstances, a nd treated exactly the sa

me throughout field and laboratory

procedures. Analyses of FD1 and FD2 give a me asure of the precision associated with sample collection, preservation, and stora ge, as well as laborat ory procedu res. 3.6 INO RGANI C CARBON (IC) - Carbon in

water sa mples from non org anic sour ces, composed mainly from dissolved minera l carbonates and carbon dioxide. I C can interfere with the determination of TOC and DOC if it is not removed.
3.7 LABORATORY FORTI FIED BL ANK (LFB ) – An aliquot of LRW or other blank matrix to whi ch a know

n quantity of KHP is a

dded in the

laborat ory . The L

FB is subjected t o the same prep aration and an alysis as a sample. The purpose o f the LFB is to deter mine whet

her the methodolog

y is in contro l, and whe

ther the laborat ory is capable of maki ng accurate and preci se measuremen ts. For thi s method, a TOC LFB is the same as a CCC (Sect. 10.3) and no additional LFB is required. One L FB is required with each DOC analy sis batch. No LFB is re quired for UVA analysis.
3.8 LABORATORY FORTI FIED SAMPL

E MATRIX (L

FM) - An aliquot of a field sample to w

hich a known quanti

ty o f KHP is ad

ded in the laborat ory . The L

FM is subjecte d to the sa

me prepa ration a nd analy sis as a sa mple, and its purpos e is to determine whether the sample matrix affects the acc uracy of the TOC or DOC analy tical re sults. The

backg round concentra

tion of or ganic c arbon in t

he sample matrix m ust be determ ined in a sep arate aliquo t and the meas ured value in the LFM corrected for backg

round concentration.
3.9 LABORATORY REAGENT WATER (L RW) - The LRW may

be distilled and/or deionized (DI) water, or

high pressure liquid chromatography (HPLC) reag ent grade415.3 - 6 or equivalent water which is low in TOC concentration, meeting the requirements as stated in Section 7.2.
3.10 MA TE RIA L S AF ET Y D AT A S HE ET (M SD S) - W ri tt en in fo rm at io n p ro vi de d b y a vendor describing a chemical’s toxicity, health hazards, physica l and chemical propert ies (fla mmability

, react ivity , etc.), storag e, handli ng, and spill prec autions.
3.11 MINI

MUM REPORTI

NG LE VEL ( MRL) - The minimu

m concen tration of organ ic carbon t hat can b e repor

ted as a q uantifie d value in

a sample following

analy sis. This concentration is determined by the background level of the analy te in the LRBs and the sensitivity of the method to orga nic carbon. See Section 9.10 for guidelines in the establishment of the MRL.
3.12 ORGANIC CARBON DETECTION LI MIT (OCDL

) - The calculated minimum concentration of a known amount of orga nic carbon (OC) added to the L RW that can be identified, measured as either TOC or DOC, and re ported with 99% confidence that the OC concentration is greater than zero a s per the procedure in Section 9.2.7.
3.13 ORGANIC CARBON (OC) - I n this method, when a concentration or instrument reading applies to either a TOC or DOC deter mination, the term “OC” may be used. For example, the LRB must not exceed 0.35 mg/L OC.
3.14 ORGANIC MATTER - A mixture of orga nic compounds (carbon-carbon, carbonhyd rogen bonded c ompounds)natural ly o ccurri ng and/ or man-ma

de that a re found in source water use d by

drinking water ut ilities. The quantit

y a nd quality of the OM i

n source water is measured by TOC/DOC instrument systems or is measured by UVA.
3.15 QUALITY CONTROL SAMPLE ( QCS) - A solution containing a known concentration of an organic c arbon compound(s) which is analy zed exactly like a sample. The QCS is obtained from a source external to the laboratory and is different from the source used for preparing the calibration standards. It is used to che ck laboratory a

nd instrument performance.
3.16 SOURCE WATER - Surface water or ground wate r that is used by a drinking water utility to produce potable water for public consumption.
3.17 SPECIF IC UV

ABSORBA

NCE AT 254

nm (SUVA)- A measu

re of DO C aromati c content that is calculated by measuring the DOC and the UV absorbanc e at 254 nm of a 0.45-μm filtered water sample. SUVA is calculated ac cording to the equation given in Section 12.2.
3.18 TOTAL CARBON (TC) - A measure of the OC and I C contained in a water sample. In this method, IC is re

moved from the sample. Therefore, the TC repor ted by a TOC instrumen t sy stem will be

equal to t he TOC or

DOC measu

rement.415.3 - 7

3.19 TOTAL ORGANI C CARBON (TOC) - The gross amount of organic matter (carbon not removed by the I

C removal step) found in natural water. Suspended particulate, colloida l, and diss olved organic matt er are a part of the TOC me asureme

nt. For th is method, the TOC definition excludes the contribution of floating vegetative or a nimal matter, and volatile organic matter found in source water. Settleable solids consisting of inorganic sediments and some orga nic particulate are not transferre d from the sample by

the labor atory analy st and ar e not a pa rt of the T OC measur

ement. 3.20 TABL

E OF ACRO

NYMS Acronym Term CB calibration blank CCC continuing calibration check
COMM-BKS commercial spectrophotometer backg round solution
COMM-SCS commercial spectrophotometer check

solution DOC dissolved organic carbon FB filter blank FD field dup licate FRB field reagent blank IC inorganic carbon IDC initial de monstrati on of cap ability KHP potassium h ydr ogen ph thalate LFB laboratory f ortified blank LFM laborat ory fortifie d matrix LRB laboratory r eagent blank LRW laboratory r eagent water MRL minimum reporting level MSDS material safety data sheet OC-CAL organic carbon calibration standa rdAcronym Term

415.3 - 8 OC-PDS organic carbon primary dilution standard OCDL organ

ic carb on detection limit QCS quality control s ample SCS spectrophotometer check solution SDWA Safe Drinking Water Act SOP standard operating procedure SUVA specific UV absorbance TC total carbon TOC total organic carbon UVA UV absorbance
4.0 CONTAMIN ATION ANDINTERFER ENCES
4.1 SPECIA

L CON SIDERATI ONS FOR O NSIT E UTILITY LA

BORATOR

IES - Aerosols (foam and mist) from the operation of a water treatment plant contain organic carbon and will contaminate glassware, reagents, sample c ollection equipment, and onsite laboratory equipment if they ar

e exposed to air at the water utility. For an onsite laborator y, it is recommended that a ir be filtered and isolated from organic fumes gene

rated by pe

troleum products and combustion gases which come fr om the ope

ration of some wate

r utility equipmen

t. Work tra

ffic in the onsite laboratory should be minimized as it may produce dust containing organic matter that will resu lt in the contaminati on of unpr otected samples a

nd labora tory equipmen

t. 4.2 All glassware must be meticulously cleaned. Wash glassware with detergent and tap water, rinse with tap water followed by reagent water. Non-volumetric glassware may then be he ated in a

muffle f urnace at 425 o C for 2 hours to eliminate interferences. Volumetric glassware should not be heated above 120 o C. Alternate cleaning procedures, such as acid rinsing and he ating at lower temperatures, may be employed, providing that these procedures are documented in a laboratory SOP and LRBs are monitored as per Section 9.9.
4.3 Laboratory

water systems ha

ve been known to contaminate samples due to bacterial breakth rough f rom resin beds, activated c arbon, a nd filters. La

borator y w ater sy

stems should be maintained and monitored frequently for carbon background a nd bacterial growth. It is rec ommended that the LRW be filtered through a 0.22-μm filter membrane to prev ent bact erial co ntaminati on of TOC in strument syst ems, rea gents,415.3 - 9 and samples. The LRW, sample transfer ( pipet), glassware, and sample bottles are the principle source for organic ba ckground in the analy

tical system. Howeve

r, it is not possible to

control a ll source s of org anic ca

rbon con tamination. There fore, th is method allows for instrument background correc tion or adjusting the zero reference point of the instrument for organic carbon bac kground that is found in the analy tical system. 2 There are many ways to corr

ect for organic car

bon background. Consult the instrument manufacturer’s operation manual for the instrument ba ckground correction procedure. Subtraction of LRB or FB measurements from TOC, DOC, or UVA sample r esults is no t allowed.
4.4 High concentra

tions of OC , both man- made and natural ly o ccurri

ng, ca n cause g ross contamination of the instrume nt sy stem, cha

nges in c alibrati on, and da mage to valves, pumps, tubi

ng, and other components. It is r ecommen ded that a naly sis of a sa

mple known to have a concentration of OC > 10 mg/L OC be followed by the a nalysis of an LRB. It is h

ighly recomme nded that known sam

ples cont aining O C concen

trations > 50 mg/L OC be diluted or not run on instruments used to ana lyze low-level drinking water samples.
4.5 Source waters containing ionic iron, nitrates, nitrites, and bromide ha ve been reported to interfere with measurements of UVA absorba nce at 254 nm. 3 The concentration of the interferences and their eff ect on the UVA cannot be determined as ea ch unique sample matrix may produce a dif ferent UVA response for the same c oncentration of interference or combination of interfer ences. This method does not treat or remove these inte rfere nces. Therefor

e, suspec ted or known interf

erence s may

affect results and must be flagged in the SUVA result as “ suspected UVA interferences.”
4.6 Chloride e

xceeding 250 mg/L

may interfe re with pe rsulfate oxidation me

thods. 4 , 5 Some instrument systems may require increased persulfate c oncentration and extended oxidation times. Consult with your instrument manufacturer’s representative or instrument operation manual for instrument setting s and reagent strengths when analy

zing samples containing high levels of chloride.
4.7 Inorganic

carbon (IC) interf

eres with TOC and DOC measurements. TOC instrument bias due to incomplete IC removal has bee n reported. 6 , 7 If inorganic carbon is not completely remove d from the water sample, it will result in a positive or negative bias depending on the way

the instrument system calculate s TOC (e.g., TOC =TC - I C, TC = TOC + IC, or TOC = TC). When inorg anic carbon (I C) is removed from the sample prior to the TOC assay , as required in this method, TOC = TC and the method bias is minimized.
5.0 SAFETY
5.1 Fast-moving source water, stee p inclines, water conduits, and electrical hazards may present special safety

considerations for the sample collector. The sample collec tor415.3 - 10 should be a

ware of any potentia l safety hazards a nd take ne cessar

y pr ecautions while collecting samples.
5.2 Each chemical r

eage nt used in t

his method

should be r

egard ed as a potential he alth hazard. Exposure to these compounds should be minimized and/or avoided by ac tive particip ation in safety

planning and goo d labora

tory practic es. 8 Each lab oratory is responsible for maintaining a current awa reness file of OSHA regulations 9 regarding the safe handling of the chemicals s

pecifie d in this met

hod. Mate

rial Safe ty D ata Sheets (MSDS) containing information on chemical and phy sical hazards associated with each chemical should be made available to all personnel involved in the chemica l analy sis.
5.3 Potassium p ersulfa te is a str ong oxidizin

g and c orrosive

reage nt. The a naly st should avoid eye a

nd skin contact by wea

ring ey e/face protection, powderless glove s and labor atory clo thin g. If body tis sue co mes in conta ct wit h thi s reagen t, app ly large quantities of water for at least 15 minutes (see MSDS) while removing contaminated clothing . This rea

gent ma y c ause del ayed burns. Seek imme diate med ical atte ntion if the are a become s irritate d or burne d. This re agent c an also c ause a f ire or explosion if it is allowed to come in contact with combustible materials.
5.4 Protect your hands by wearing laboratory

disposable gloves during the prepara tion and dispos al of cor

rosive ( acids an

d oxidants)laborat

ory reage nts. Do not

reuse laboratory g

loves that have been discarded or are suspected of being contaminated.
6.0 EQUIPME NT AND SUP PLIES

NOTE: Brand names, and/or catalog numbers are included for illustrative purposes only. No endorsement is implied. Equivalent performance may be achieve d using apparatus, instrument systems, and reagents other than those that are illustrated below. The

laboratory

is respons ible for the

assurance

that altern ate produc ts, apparatus, instrument systems, and reagents demonstrate equivalent performance as specified in this method.
6.1 FIL

TER APPARAT

US - Nalg ene® or C orning® 250 mL Filter Sy stem, 0.45 -μm Nylon (NYL

) or Polyethersulfone

(PES) Low Extractable Membrane/Poly styrene Body with optional g lass fiber prefilters (nominal 1 to 7 um). Packaging and filter apparatus are recy

clable (NALGE-

NUNC International: Nalg ene Labwar e CAT. numbers NYL: 153-0045, PES: 168-0045). I t is recommended that filter membranes be hydrophilic 0.45-μm filter mater ial.
NOTE: Alternate filter membranes (e.g., polypropylene, silver or Teflon® ), apparatus technolo gies suchas cartrid

ges, reus able filte

r bodies, s

yringe fil ters, and t

heir associated syringes, peristaltic pumps or vacuum pumps may be selected. The complex ity of an alt

ernative filter appa ratus is lef

t to the ana lyst’s ing

enuity providing that the apparatus meets quality control and initial demonstration of415.3 - 11 capability requirements as stated in Section 9.3.2, and that FB requirements are met (Sect . 9.9). It is reco mmende

d that the a nalyst re

view the A WW

A journal ar

ticle “Selecting filter membranes for measuring DOC and UV 254 ”, Karanfil, e t. al. 10, prior to the selection of an alternative filter membrane, apparatus, and wash procedure. Karanfil tested 11 filter membranes (0.45-μm pore size and 47-mm disc size) represe nting four d

ifferent m anufactur

ers and se

ven diffe rent type s of filter m aterials for both de

sorption an d adsorptio n. Hydrop hilic poly ethersul fone (P ES) filte rs available from two manufacturers (Osmonics Micro-PES and Gelman Supor 450, both 0.45 m icron abso lute pore size and 47

-mm disc size) a nd a hydro

philic polypropylene filter (Gelman GH Polypro, 0.45 micron absolute pore size and 47-mm disc size) were found to be the best options among those tested in the study.
6.2 INJECTION V

IAL S - Specially cleane d 40-mL glass vials, with cap and polytetrafluoroe

thylene (PTFE)

/silicone septa. Eagle-Picher TOC Certified, Cat. No. 40C-TOC/LL, Ea

gle-Picher Technologies®. The se vials are specially cleaned by

the manufacturing process a

nd certi fied to c ontain < 1 0 μg TOC. V ials may be reuse d if cleaned as per S ection 4.2. The PTFE /silicone septa onc e pierc ed by

the sample injector must be discarded.
6.3 INSTRUMENT SYSTEMS - The TOC and UVA proce dures allow for the use of severa l differ ent ty pes or combinations

of TOC inst

rumenta l sy stem tech

nologie s. Examples of typical TOC instrument sy stems, as well as a UV spectrophotometer, are described below. Data from these instruments may be found in Section 17. Only one TOC instrument is required to perform this method.
6.3.1 TOC I

NSTRUMENT

1: UV/Per sulfate/

Wet Oxidation

with Permeation/Conductivity Detection. The I onics-Sievers® 800 TOC analy zer is based on UV cata

lyze d persulf

ate dig estion to produce C O 2 , which is detected by

a membrane permeation/conductivity detector

. 6.3.2 TOC INSTRUMENT 2: Elevated Tempera ture/Catalyzed/Persulfate/Wet Oxidation/N ondispersive I nfrare d Detec tion (NDI

R). The O .I. A

naly tical® TOC Model 1010 is based on elevated temperature (95-100°C) c atalyzed persulf ate dig estion to produce C O 2 , wh ich is th en d ete cte d by a n ND IR detector.
6.3.3 TOC INSTRUMENT 3: UV/L ow Temperature/Persulfate/Wet Oxidation/N

DIR. The Tekmar-Doh

rmann® Pho enix 8000 TO C analy zer is based on UV cata lyze d persulf

ate dig estion to produce C O 2 , which is then detected by

an NDIR detector.
6.3.4 TOC INSTRUMENT 4: Cataly zed/Combustion Oxidation(680 °C)/NDIR. The Shimadzu® model TOC-5000A analyzer is based on a catalyzed415.3 - 12 combustion in air or

oxyg en reag ent gas

to produc e CO 2 , which is then detected by

an NDIR detector.
6.3.5 TOC INSTRUMENT 5: High Temper ature Combustion Oxidation/NDIR. The Thermo Environmental® ThermoGlas TM 1200 TOC is based on a dual zone furnace with individually a djustable ovens from 700 to 1250 °C for final high tem peratur e combust

ion of the sample wi

th air or o xyg en reag ent gas to produce CO 2 , which is then detected by an NDIR detector.
6.3.6 UV SPECTROPHOTOMETER: The spectrophotometer is used for the UVA determination only. The spec trophotometer must be able to measure UVA (254 nm), with an absorbance from 0.0045 to at least 1.0 cm -1 UVA, and accommo dates a s ample ce ll with a pa th lengt h of 1, 5, or 10 cm.
6.4 LABORATORY REAGENT WATER TREATMENT SYSTEM - The LRW used for the development of this method was generated using a Millipore®, Milli-Q Plus Ultra-Pure Water Treatment Sy stem with a 0.22-μm sterile pack filter capable of producing organic ca

rbon free (< 0.010 mg/L

OC), ultrapure deionized water. 11 The maximum amount of OC allowed in the LRW for this method is 0.35 mg/L. When purchas ing a tr

eatment syst

em for g eneral

laborat ory use, it is r

ecommen ded that a system be purcha sed capable of producing L RW of the above stated quality in order to be of use in other laboratory analyses.
6.5 MUFFLE FU

RNACE - A muffle furnace capable of heating up to 425 °C.
6.6 FIEL

D SAMPLE pH TEST - Sample pH indicator test strips, non-bleeding (colorpHast® Indicator Strips 0 - 2.5, c at. 9580), EM Science, 480 Democrat Road, Gibbstown, N.J. 08027. Pocket pH test kits, pocket pH meters, or laboratory pH meters are acceptable for

field sample pH measurements.
6.7 PIPET , DISP OSABL E TRANSFE

R - La rge vo lume bulb ( 15mL) , non-ste rile, with flexible long stem polyethy lene transfer pipet. “Sedi-Pet TM”, Fisher Scientific® Cat. 13-711-3 6. Pipets a

re used f or sample transfe r from the middle of a

sample bo ttle containing floating material (scum).
6.8 SAMPLE COLL

ECTION REAGENT BOT TLES - Specially cleaned, 1-L B oston round g lass bottle s with cap . Eagle -Picher TOC Certif

ied, Cat. No. 112-01 A/C TOC, Eagle-Picher Technolog ies, LL C. These bottles are specially cleaned by

the manufacturing process and ce rtified to meet EPA OSWER Directive # 9240.0-05A “Specifications And Guidance For Contaminant-Fr ee Sample Containers 12/92.” Amber bo ttles are

prefer red, but c lear g lass bottle s may be used if

care is taken to protect samples from light. The laboratory may select g

lass bottles of any volume that meet the utility and laboratory sample processing and quality control sampling needs.415.3 - 13 Glass bottles may be re

used after cleaning (see

Sect. 4.2 for glassware cleaning instructions) or discarded.
6.9 SPARGE APPARATUS - N-EVAP TM , Nitrogen Evaporator System Model 111, Organomation Associates I nc. This apparatus is not used for its originally designed purpose o f evapor

ating sa mple extra

cts. I n this metho d, the app aratus is used as a sparging device. The stainless stee l needles of the apparatus are lower ed into the 40- mL sample vials containing the TOC or DO C samples to remove inorganic carbon by sparging with nitrogen g as. Alt ern ate ly, s om e TO C au to -sa mp ler s pr ovi de a pre -sp arg in g or mem bra ne IC removal option prior to injection of the sample into the TOC instrument system. The analyst is encoura

ged to utilize these instrument options, if available. Another alternative is for the laboratory analyst to fabric ate a sparging appa ratus. For example, an apparatus may consist of copper tubing from a reg ulated gas source, connec ted to a ne edle val ve used f or gas f low contr ol, a leng th of silic one tubing

with a glass Pasteur pipet inserted into the tubing and a ring stand with clamp for positioning

the pipet . The Past

eur pipe t is insert ed into the

sample bo ttle or via

l to remove i norga nic car bon by spargi ng with n itroge n gas (S ect. 11.5 ). The c omplexity of the alternative sparging a pparatus is left to the analy st’s ingenuity providing that th e ap par atu s m eet s qu ali ty co nt rol and in it ial dem ons tra ti on o f ca pab il it y (IC removal test) requirements as stated in Section 9.2.4.
6.10 VACUUM SOURCE - Aspirator, air flow or water flow, hand-ope rated or low pressure electric vacuum pump, providing a vacuum of 15 inches of mercury (Hg) or better. If an alter

native choice is made, see note in Section 6.1.
6.11 VARI

ABLE PIPE TTES - Prog

ramable automate d pipette s. Rainin I nstrumen t® EDP-Plus Pip ette 10ml, Cat. No. EP-10 mL ; EDP-Plus Pi pette 100 0 μL, Ca

t. No. EP1000; EDP- Plus Pipette

100 μL , Cat. No. E

P-100, or manual va

riable p ipets with disposable tips having a calibrated rang e of 0 to 100-μL, 0 to 1000-μL , and 0 to 10 mL.
6.12 VOLU

METRI C FLA SK AND PI PETS - All vo lumetric

glassw are use d in this method are required to be “Class A”.
6.13 WAVELENGTH VERI FICATI ON FIL

TER SET- Wavelength verification may be provided by the instrument manufa cturer, a scientific instrument service company , or if this not practical, wavelength verification may be made by the

laboratory using certified spectrophotometric filter sets with values trace able to NIST. Fisher Scientific Cat. No. 14-385-335, Spectronic No. 333150.415.3 - 14

7.0 REAGENTS AND STANDARDS

NOTE: The chemicals required for this method must be at least reagent grade. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society (ACS) and/or ACS c ertified, when avai lable. Som e instrume nt manufac turers provide reagents specifically prepared for the optimum performance of their TOC instruments and provide calibration services and/or calibration standards. The analyst is allowed to use these services or prepare reagents and/or standards accordin g to the ins trument m anufactur er’s ope ration man ual.
7.1 COMPRESSED GASES – Carbon dioxide free Ultra High Purity (UHP) g rade nitrogen gas or an optional Ultra-low leve l TOC gas delivery system. For combustion based TO C systems, zero grade air and U HP grad e oxy gen may be need ed. The u se of lesser grades of compre ssed gases will result in high backgr ound noise in the TOC instrument systems. The TOC I nstrument 1 described in Section 6.3.1. does not require compressed gasses for operation.
7.2 LABORATORY REAGENT WATER (L RW) - Water that has a TOC reading of < 0.35 mg/L and < 0.01 cm -1 UVA. Although the LRW TOC

and UVA l imits in this method are 0.35 mg/L a

nd 0.01 cm -1, respectively , the system specified in Section 6.4 is capable of producing better quality organic carbon free , ultrapure deionized water. For optimum performance, it is recommended that L RW with < 0.05 mg/L TOC and < 0.0045 cm -1 UVA be used for this method. Alternatively , LRW may be purchased (ACS HPLC grade or e quivalent).
7.3 DISODI

UM HYDROGEN PHOSPHATE, [Na 2 HPO 4 , CAS# 7558- 79-4 ] - Anhydrous, ACS gr

ade or better.
7.4 O-PHOSPHORIC ACID (85%), [H 3 PO 4 , CAS# 7664-38-2] - ACS grade or better.
7.5 POTASSIUM DI

HYDROGEN PHOSPHATE, [KH 2 PO 4 , CAS# 7778- 77-0 ]- Anhydrous, ACS gr

ade or better.
7.6 POTAS SIU

M HYD ROGE

N PHTH AL ATE (KHP) , [C 8 H 5 O 4 K, CAS # 877- 24-7 ] - Anhydrous, ACS gr

ade or better.
7.7 REAGENT SOLUTI ONS FOR WET CHEMICAL OXIDATION - It is assumed that each instrument manufacturer has optimized reag ent solutions for their respective instruments and has provided the instructions for the preparation of rea gents in the instrumen t’s oper ation man ual. NOT E: TOC Instrument 1 does not require gas sparge of reagents as the manufacture provides reagent packs for the operation of the instrumen t.415.3 - 15 7.7.1 PERSULFATE REAGENT - Prepar e this solution according to the instrument manufacturer’s instructions or purchase the solution from the instrument manufacturer. If the lab oratory prepar es the sol ution, tra nsfer th e solution

to the instrument reagent bottle and cap. I t is recommended that this solution be sparged gently

with carbon dioxide free UHP grade nitrog en gas for approxima

tely 1 hour. I f the instr

ument sy stem provides cont

inuous spa

rge, it is recommended tha

t the rea gent bo ttles be a

llowed to s

parge for 10 min

utes to 1 hour before operating the instrument. Self containe d reagent packs or other types of rea

gent syste ms may not require r

eagent sparging . Discard the solution as per expiration time/date listed in the manufacturer’s operation manual.
7.7.2 PHOSPHORIC ACID SOL UTION - Prepar

e this solution according to the instrument manufacturer’s instructions or purchase the solution from the instrument manufacturer. I f the laboratory prepares the solution, transfer the solution to t

he instru ment rea gent bo ttle and c ap. I

t is recom mended that this solution be sparged gently with carbon dioxide free UHP grade nitrog en gas for approximately 1 hour. If the instrument system provides continuous sparge, it is recommended that the reagent bottles be allowed to sparge for 10 minutes to 1 hour before operating the instrument. Self contained re agent packs or other ty

pes of reagent sy

stems may not require r

eagent sparging

. Discard the solution as per expiration time/date listed in the manufacturer’s operati on manual

. 7.8 STANDARD SOLUTI ONS NOTE: Consult with the instrument manufacturer or operation manual for the recommended concentrated acid used for preservation of standard solutions. The concentrated acid used to preserve the standards is usually HCl, H 2 SO 4 , or H

3 PO 4 depending upon the instrument operation manual recommendation. The acid used for the standards must be the same as the one used for the samples. Standard solutions may be alternatively prepared in larger or smaller volumes and concentrations as needed for the calibration of instruments. Standard solutions may be prepared by gravimetric or volumetric techniques. This section provides guidance for the preparation of calibration solutions.
7.8.1 INORGANI C CARBON PRIMARY TEST SOLUTI ON (IC-TEST) REAGENTS
7.8.1.1 AMMONIUM CHL ORIDE, [NH 4 Cl, CAS# 12125-02-9] - ACS grade or better.
7.8.1.2 CALCI

UM CHL ORID E DIH

YDRATE, [Ca

Cl 2 C 2H 2 O, CAS# 10035- 04-8] - ACS grade or better.415.3 - 16 7.8.1.3 CALCIU

M NITRATE TETRAHYDRATE, [Ca(NO 3 ) 2 C 4H 2 O, CAS# 13477-34-4] - ACS grade or better.
7.8.1.4 MAGNESI

UM SUL FATE HEPTAHYDRATE, [MgSO 4 C 7H 2 O, CAS# 10034-99-8] - ACS grade or better.
7.8.1.5 POTASSIUM CHLORI DE, [KCl, CAS# 7447-40-7] - ACS grade or better.
7.8.1.6 SODI

UM BI CARBONATE, [NaHCO 3 , CAS# 144-55-8] - ACS grade or better.
7.8.1.7 SODIUM CHL ORIDE, [NaCl, CAS# 7647-14-5] - ACS grade or better.
7.8.1.8 SODIUM-META SI LI CATE NONAHYDRATE, [Na 2 SiO 3 C 9H 2 O, CAS# 1 3517- 24-3 ]
7.8.1.9 SODIUM PHOSPHATE DI BASIC HEPTAHYDRATE, [Na 2 HPO 4 C 7H 2 O, CAS# 7782-85-6] - ACS grade or better.
7.8.2 PREPARATION OF THE IC- TEST SOL UTIO N, 100 MG/L

IC - T his solution is u sed in the

perfor mance of the I C removal

spargi ng eff iciency test (Sect. 9.2.4 ). The ionic content of the I C-TEST mixture solution was chosen from a previous investigation in which the authors wanted to simulate waters likely to be foun

d in waste

treatme nt plants. 12 Because the inorganic sa lts are not soluble in a single concentrated solution, prepare four separate stock solutions by di luting e ach of the followi ng to one liter with LRW:415.3 - 17 FLASK (1 L) SALT WEIGHT (g) A magnes ium sulfat e heptah ydr ate, Mg SO 4 C 7H 2 O 2.565 B ammonium chloride, NH 4 Cl 0.594

calcium c hloride d ihydrate, Ca

Cl 2 C 2H 2 O 2.050 calcium nitrate tetrahy

drate, Ca(NO 3 ) 2 C 4H 2 O 0.248 potassium c

hloride, KCl 0.283 sodium chl oride, N aCl 0.281 C sodium bic arbonat e, NaHCO 3 2.806 sodium phosphate dibasic heptahydr ate, Na2 HPO 4 C 7H 2 O 0.705 D sodium-meta silicate nonahydr ate, Na2 SiO 3 C 9H 2 O 1.862 Prepare a 102.5 mg/L

IC-TEST mixture, based on bicarbonate ca lculations and impurities, by adding a 10-mL aliquot of each of the above solutions to a 40-mL vial. Add 40 μL of H 3 PO 4 , HCl, or H 2 SO 4 , depending upon instrument require ments (se e note, Se ct. 7.8), to the 40- mL inje ction via l. An I C-TEST mixture of a

pproximate ly 1 00 mg/L

was chos en to represent the extreme inorganic carbon concentra tion the analyst may

encounter. Although the mixture is turbid after preparation, clarification occurs af ter acidification.
7.8.3 ORGANIC CARBON PRI MARY DIL

UTION STANDARD (OC-PDS), 500 mg/L (1 mL

= 0.5 mg OC) - Prepare an ac id preserved (pH # 2) OC-PDS by pouring approximately 500 mL of LRW into a 1-liter volumetric flask, adding 1 mL of concen trated a cid for preserv ation (se e note, Se ct. 7.8), caref ully transferring 1.063 g KHP into the L RW, stirring until it is dissolved, and then diluting to the mark with LRW (1.0 mg KHP = 0.471 mg Organic Carbon). Transfer this solution to a marked amber glass re agent bottle and cap for storag e. This sol

ution does

not requi re ref riger ation for storag e and is st

able for an in definite period of time (6 mon

ths to a y ear). Re place the OC-PDS if the instrument system fails to pass the QCS requirements (Sec t. 9.11).
7.8.4 ORGANIC CARBON CAL IBRATI ON (OC-CAL) - At least 4 c alibration concentrations and the CB (i.e., a minimum of 5 total calibration points) are required to prepare the initial calibration curve . Prepare the calibration standar ds over the conce

ntration r ange o f intere st from dil

utions of the OCPDS. The calibration standards for the development of this method were prepared as specified in the table below. Calibra tion standards must be415.3 - 18 prepared using L

RW preserved to pH # 2 with concentrated acid (see note, Se ct . 7 .8 ). Fi lt ra ti on of

th e C AL s ta nd ar ds fo r D OC an al ysi s i s u nn ec es sa ry, since interferences from the filtration unit are monitored via the FB. Therefore, the OC-CAL

may be applied to TOC or D OC determinations. The OC-CAL standards must be sparg ed, or otherwise treated for IC removal, like a sample following the procedure in Section 11.5.

PREPARATION OF CALIBRATION (OC-CAL) CURVE STANDARDS

CAL Level Ini tial

Conc. of OC-PDS (mg/ L) Vol. of

OC-PDS (mL) Final Vol. of

OC-CA L Std. (mL) Final Conc. of

OC- CA L Std. (mg/ L) CB – 0 1000 – 1 500 1.0 1000 0.5 2 500 2.0 1000 1.0 3 500 4.0 1000 2.0 4 500 10.0 1000 5.0 5 500 20.0 1000 10.0 6 * 500 5.0 100 25.0 7 * 500 10.0 100 50.0 * Note: OC-CAL 6 - 7 are optional ca libration standards for use when operating the instrument in a higher conc entration range. The calibration blank (CB) is a “0.0 mg/L OC ” standard which approximates zero mg/L OC concentra

tion plus the background carbon contributed from the LRW. The CB is stored and treated the sa me as all other calibration standar ds. When an

aly zed, the CB must not exce ed 0.35 mg /L TO C.
7.8.5 Calibrat

ion standa

rds may be store d at room te

mperatu re in amb er gla ss bottles (Sect. 6.8) and/or in a dark cabinet (if clear glass used) for a period of 30 days. If

stored OC -CAL s are use d to reca librate t he instru ment durin

g this 30 day period, the CB which has been stored with the OC-CALs must be analyzed as a sa

mple prior to recalibration. The CB must not exceed 0.35 mg/L OC. I f the CB does not meet this criteria, the CB and OC-CAL s may have absorbed OC from the laboratory atmosphere and must be discarded.
7.9 COMMERCIAL SPECTROPHOTOMETER CHECK SOL UTION (COMM-SCS) - The laboratory

may use a c ommercially pre pared COMM-SCS for the purpose of checking the performance of the spectrophotometer. The analy st should purchase the COMM-SCS in the absorbance range that is commonly observed for the samples415.3 - 19 analyzed. The I

N-SPECTM optical standard and background solution for a 254 nm spectro photometr

ic check is NI ST trace able, an d is availa

ble from G

FS Chemic als, PO Box 245, Powell, Ohio 43065.
7.9.1 COMMERCIAL SPECTROPHOTOMETER BACKGROUN D SOLUTI ON (COMM-B KS) - A ba

ckgro und solution provide d by

the COMM- SCS provider that is use d to corr

ect for stabilizing

agents present in the COMM

SCS.
7.10 LAB ORATORY PRE PARED KHP- SPECTROPHOT OMETER CHE CK SOLUTI ONS (KHP-SCS) - The laboratory may elect to prepare a KHP based spectrophotometer check solution (KHP-SCS) for the purpose of chec king the performance of the spectrophotometer a t the absorbance of the averag e UVA sample. This requires the preparation of a buffe red KHP solution having a known concentration and a known absorbance a t 254 nm. The analyst should prepa re the KHP-SCS that will provide an absorbance similar to the absorbance in the rang e (low, mid, high ) of the s ample analy

zed. NOTE : If the phosphate buffer reagents used below have been exposed to laboratory humidity, it is recommended that potassium dihydroge

n phosphat

e (KH

2PO 4 ) and dis odium hyd

rogen pho

sphate ( Na 2HPO 4 ) be dried for 1 hour at 105 °C.
7.10.1 KHP-SCS-B LANK - Prepar e a 1-L volumetri c flask c ontaining approxima

tely 500 mL of L

RW. Transfer and dissolve 4.08 g anhy drous KH 2 PO 4 and 2.84 g anhydrous Na

2 HPO 4 in 500 mL. Dilute to the mark with LRW and transf er to a 1-L amber g lass bottle.
7.10.2 KHP-SCS - Pr

epare t he KHP-SCS t

hat will pr

ovide an a

bsorbanc e similar

to the absor bance o f the samp les anal yze d. Prepa

re a 1-L volumetri c flask containing approximately 500 mL of LRW. Transfer and dissolve 4.08 g anhydrous KH

2 PO 4 and 2.84 g anhy

drous Na 2 HPO 4 into the 500 mL of LRW. From the example calculation, or table located below (Sect. 7.10.2.1) , transfer the amount of OC-PDS (in mL) needed to produce the representative absorba nce of the sample

into the buffere d KHP-SCS an d dilute wi

th LRW to the 1 L mark.
7.10.2.1 KHP-SCS, CONCENTRATION CALCUL ATION - Standard Metho d 5910 B provi des fo r a spec troph otom eter ch eck us ing a correlation equation which was based on the ana lyses of 40-samples of KHP solution. 3 The correlation formula is as follows: UV 254 = 0.0144 KHP + 0.0018. This formula may be algebraically

solved for the conc entration of KHP, e xpressed a s mg/L

OC, need

ed to produce a KHP-SCS for the observed sample absorbanc e as follows:415.3 - 20 KHP-OC conc. = (UV 254 ! 0.0018) ' 0.0144 Using the calculated KHP-OC concentra tion, determine the amount of OC-PDS (Sect. 7.8.3, 1 mL = 0.5 mg OC) nee ded to produce a known abs orbance

for the K HP-SCS. For

example, if

you typ ically run samples that have an averag e UVA equal to 0.08 cm -1 , you can calculate the KHP in the following manner: 5.431 KHP mg/L as OC = (0.08 cm -1 UVA 254 ! 0.0018) ' 0.0144 The 5.431 mg/L

is the same

as 5.431 mg

/L KH P. It f ollows tha

t to produce a 1-L KH

P-SCS solution having a UVA absorbance of 0.08 cm -1 , you will need 10.9 mL of OC-PDS as calculated below: (5.431 KHP-SCS mg/L)(1000mL /L) / 500 OC-PDS mg/L

= 10.9 mL of OC-PDS
In su mmary , 10.9 mL

OC-PDS is ne eded to ma ke a 1-L KHP-SCS solution that will have a UVA absorbance of 0.08 cm -1

. Alternately, the f

ollowing table, which is based on the above calculation, can be used. From this table, cross ref erence the amount of the OC- PDS (in mLs) needed to produce the desired UVA for the KHP-SCS. Transfer the required amount of O C-PDS into a 1-L flas k and dilute to the mar

k with LRW

. KHP-SCS Preparation UVA@254nm (cm -1 ) ORGANIC

CARBON (mg/L) OC-PDS ( mL

added per liter of LRW) 0.0738 5 10 0.1458 10 20 0.2898 20 40 0.4338 30 60

7.10.3 Verify

that the K

HP-SCS-BL

ANK and t

he KHP-SCS b

uffere d solutions

are at pH 7. Check the pH by pla cing a drop from the SCS bottle onto pH test paper. Do not put the pH paper into the SCS bottle. Placing the pH paper in the bottle will contaminate the sample with organic carbon. If this happens, the spectrophotometer check solution must be discarded and a new solution prepared in a clean bottle. I f the buffered KHP-SCSs are not at a pH of 7, the415.3 - 21 solution must be discarded and a new solution made. Store these solutions at ap pr ox im at el y < 6 °C. These solutions a

re not pr eserve d. In

a sterile environment these solutions may be stable f or a month. However, the shelf life of these solutions may be shortene d as a result of microbial growth. Theref ore, it is recommended that the above solutions be made fresh weekly and/or be replaced if any

significant change in absorba nce is noted.
8.0 SAMPLE C OLLECTION, FILTRATION, AND HOLDIN G TIMES NOTE: Consult with the instrument manufacturer or operation manual for the recommended type of concentrated acid used for prese rvation of TOC or DOC samples. The concentrated acid used to preserve the sample is usually HCl, H 2 SO 4 , or H 3 PO 4 dependin

g upon the

instrumen t operatio n manual re commen dation. The

acid used for th e standard

s must be th e same as

the one us ed for the

samples. Samples for DOC and UVA analyses may be filtered in the field using alternate apparatus technolo gies suchas cartrid

ges, reus able filte

r bodies, s

yringe fil ters, and t

heir associated syringes, peristaltic pumps or vacuum pumps providing that the filter blank requirements are met (Sect. 9.9)

. 8.1 SUVA SAMPLE COLL ECTION - SUVA is determined by the analysis of a D OC sample a nd a UVA s ample, to gether called the SUVA sa

mple set. A

single s ample may be collec

ted and split for the DOC and UVA analyses or two individual samples may be collec

ted at the same time. For example: if the sample is to be determined by two separate laboratories (i.e., one lab de termines UVA and a second lab determines the DOC), the sample collector may collect two representative samples for shipment. A 1-L volume is recommended for the collection of DOC and UVA samples, but other volumes may be collected depending on the sample volume needed for the filtration apparatus used by

the analyzing la

boratory. The

SUVA sample set is collected in clean glass bottles by

filling t he bottle almost to the top. The

sample se

t is NOT preserved with acidat the time

of colle ction. The

sample se

t is delive red as so on as possi

ble to the labor atory and should

arrive packed in ice or frozen g el packs . The samp le set is process ed by

the labor atory and store d at <

6 °C, until a

naly sis. I f there

is no visible ice or th e gel pa

cks are complete ly thawed, the labora tory should re port thes e conditions to the data user. Samples shipped that are improperly preserved, and/or do not arrive at the laboratory within 48 hrs, cannot be used to meet compliance monitoring requirements under the Safe Drinking Water Act (SDWA).
8.1.1 The DOC sample must be filtered in the field or in the laboratory within 48 hours of sample collection according to the proc edure detailed in Section 11.4 prior to acidification and analysis. After filtration, the DOC sample is acidified with 1 mL of concentrated a cid per 1 L of sample or the sa mple is preserved by drop wise adjustment to a pH < 2 (Sect. 8.3). The DOC bottle is capped and inverte d severa

l times to mix th e acid a

nd is store d at < 6 °C. The sa mple must be analyzed within 28 day s from time of collection.415.3 - 22 8.1.2 The UVA s ample must be filter ed in the f

ield or in t

he labor atory accord ing to the procedure detailed in Section 11.4. The sample used for the UVA determination is notacidifie d. The UV A bottle is

capped and store d at < 6 °C for up to 48 hours from the time of collection. The UVA sample must be analyzed within 48 hours from the time of c ollection.
8.2 TOC SAMPLE COLL ECTION - The ty

pical sample volume collected may vary fr om 40 mL to 1 L of sa

mple. It is recommended that the sample c ollector coordinate the size of collection volume with the needs of the analy tical laboratory . If the TOC sample is collected in a 40-mL injection vial, it is acidified to pH < 2 by addin g 2 drops of concentrated acid. I f the TOC sample is collected in a 1-L bottle, 1 mL of concentrated acid is added or the sample is drop wise a djusted to a pH < 2 (Sect. 8.3). TOC samples must be acidified at the time of collection. Cap the bottle or injection vial and i nvert se veral times to mix

the acid. The sample is delivered as soon as possible to the laboratory a nd should arrive packed in ice or frozen g el packs. If there is no visible ice or the gel packs are completely thawed, the laboratory

should report the conditions to the data user. Samples that are improperly preserved or shipped, cannot be used for compliance monitoring under the SDWA. The sample is stored at < 6 °C, until analysis. Stored and preserved samples must be analyzed within 28 days from time of collection.
8.3 SAMPLE

pH CHECK -The pH of the pres erved sa

mple (DO C, TOC only

) or filtr ate should be c

hecked to ensure adequa te acidif ication f or the pr eserva tion. This should only be perf

ormed by an a

dequately tra

ined sample collector. Check the pH by placing a drop from the sample onto pH test paper. Do not put the pH paper in to the samp le bottle. Pla

cing the pH paper in the samp le bottle w

ill contam

inate the sample wi

th organic carbon. I f this happens, the sample or filtrate must be discarded and a ne w sample collected.
9.0 QUALITY CO NTROL
9.1 Each lab oratory

using thi s method is r

equired to opera te a for mal qualit

y c ontrol (Q C) program. QC requirements for TOC include: the initial demonstration of labor atory capability (I

DC) followed by re gular analyses of continuing calibration checks (CCC), independ ent quali ty c ontrol sa

mples (QCS ), labor

atory reage nt blanks (LRB) , field duplicates (FD), and laboratory fortified matrix samples (LFM). For this method, a TOC labor

atory fortifie d blank (L

FB) is the same a s a CCC (Sect. 10.3) a nd no L FB is required. QC requirements for DOC include: the I DC followed by reg

ular analyse s of CCCs, QCSs, f

ilter bla nks (FB ), LF B, FDs, and L FMs. For laboratories analy

zing both TOC and DOC samples, only the DOC I DC determination is required, as it is similar to, yet more rigorous than, the TOC ID C. The IDC must be performed the first time a new instrument is used and/or when a new analyst is trained.415.3 - 23 QC requirements for UVA analy sis include: the performance of the I DC followed by the regular analy

sis of spectrophotometer check solutions (SCS), FBs, and FDs. For UVA analy sis, no LFB or DL determination is required. The control of instrument background is crucial prior to the performance of the I DC. It is required that a critica l evaluation be made of the instrument background 2 associated with an instrument system be fore proceeding with the I DC. Once an acceptable instrument background is established, it is safe to proceed with the IDC. In summary, this section describes the minimum acceptable QC program, a nd laborat ories ar e encou raged to institute

additiona l QC practices to me et their s pecific needs. T he labor atory must mainta

in recor ds to document the qu

ality of the da ta generated. All users of this method are e ncouraged to write their own SOPs stating exactly how their lab executes the me thod. A summary of QC requir ements can be found in Tables 17.5 and 17.6.
9.2 INI TIAL

DEMONSTRATION OF CAPAB ILITY FOR TOC DETERMI NATION
9.2.1 INI TIAL

DEMONSTRATION OF L OW SYSTEM BACKGROUND - Before any samples ar

e analyzed, a

nd any time a new

set of reagents is used, prepare a laborat ory reage nt blank (LRB)

and demon strate that it meet s the crit eria in Section 9.9.
9.2.2 INI TIAL

INSTRUMENT CALIBRATI ON VERIFICATION - Prior to the analysis of the I

DC samples, calibrate the TOC instrument as per Section 10.2. Verify c alibration accuracy with the preparation and analysis of a QCS as defined in Section 9.11.
9.2.3 INI TIAL

ORGANIC CARBON FL OW INJECTION MEMORY CHECK - Inject the highest OC-CAL used, followed by two injections of the LRB. I f the first LRB is > 0.35 mg/L

OC and the second LRB is in QC compliance ( i.e., < 0.35 mg/L OC), a memory problem is indicated. Therefore, an L RB may need to be

placed a fter ev ery sample. If the instr

ument sy stem provides a rin se or system flush with LRB betwe en inj ectio ns, ac tivat e the ev ent co ntrol setti ngs and repeat this section. If the memory problem persists, then an LRB must be placed after every

sample.
9.2.4 INORGANI C CARBON REMOVAL SPARGI NG EFFICI

ENCY TESTVarious sample sparge times (3-10 minutes) and spar ging flow rates have bee

n reporte d for the

removal of IC

. 13 A mul ti-l aborat ory study rep orted large variations and positive bias in analyse s of solutions of standards containing even sma ll amounts o f IC, demonstr ating th e importa

nce of IC removal

. 14 Since IC must be removed in order to re duce interferences with the TOC and415.3 - 24 DOC quantitation, an IDC of the I C removal is performed. Please note: any manipulation of the sample may inadve rtently introduce organic carbon from the appa ratus. Prepare an inorganic ca

rbon mixture, IC-TEST solution, as specified in Section 7.8.2. Using the procedure outlined in Section 11.5, sparge at least three portions o f the ac idified IC-TEST solu tion in the s ame manner, and o f the same volume, as field samples will be sparged. After the I C-TEST solution is treated by th e IC r emo val app ara tu s, a nal yze t he s ol ut io n as an LR B fo r OC . Th e IC removal appara tus must pro duce an

accept able I C-TEST by

meeting the LRB requirements as stated in Section 9.9. These I C removal parameters are then used for all subsequent samples. The sparging time recommende d in Section 11.5.2 is based on a sparging study with an N 2 flow rate of approximately 200 mL/min and a pH of 2.0. The following inorganic carbon conc entration reduction was observed after the external sparging of a 40-mL IC-TEST solution:

IC REMOVAL

SPARGE EFFICI

ENCY STUDY spargi ng time ( minutes) 0 5 10 15 20

con cen tra ti on IC (mg/L), measure d as OC interference 102.5 6.11 0.611 0.049 0.044

The LRB du ring th e abov e stud y was < 0.05 mg/L, th us a 20 -minu te spa rge time ensured that no measurable organic c arbon remained in the sample. The abov e sparg e effic iency table sho uld be use d only

as a gu ide. The analy st may find that a hig

her flow rate may

reduce the time necessary to remove the inorganic carbon to a level at or ne ar the TOC measurements found in the L RB. The IC-TEST solution is also used to test alternate I C removal apparatus that remove I C by interna l chemica l treatme nt, alter nate spa rging procedu res, and/or membrane IC re

moval. Any alterna

tive procedure or I C removal appara tus must be t

ested usi ng the IC-TEST solu

tion and me et the L

RB requirements as stated in Section 9.9.
9.2.5 INI TIAL

DEMONSTRATION OF ACCURACY - The initial demonstration of accura cy consists o f the ana

lys is of five

(5) L FBs ana lyze d as sampl es at a concentration between 2 to 5 mg/L OC. If DOC analy

sis is being performed, the LFB must be filtere d according to the procedure in Section 11.4. The average recove

ry betwee n 2 to 5 mg/L OC must be within ±20% of the true415.3 - 25 value. If ±20% of the true value is exceeded, identify and correct the problem and repeat Sections 9.2.5 and 9.2.6.
9.2.6 INI TIAL

DEMONSTRATION OF PRECI SION - Calcu late t he aver age precision of the r

eplicate s in the I

nitial De monstrati on of Acc

uracy (Sect. 9.2.5). The RSD% must be no greater than 20%. If the RSD% exceeds 20%, identify and cor

rect the problem and repeat Sections 9.2.5 and 9.2.6.
9.2.7 ORGANIC CARBON DETECTION LI MIT (OCDL

) DETERMINATION - The OCDL determination must be conducted ove r at least three (3) day

s with a minimum of seven (n=7) replicate L FB analy ses. Before conducting the initial OCDL, the OC-CAL -1 standard is used to estimate the starting concentration for the OCDL stud y. If DOC analyses are being performed, th e low-level LFBs must be filtered according to procedur e in Section 11.4 prior to analysis for the OCDL . If t

he instru ment can easily detect the OC-CAL -1 standa rd, the a naly st should lower the concentration to a level so that theLFB produce s a signa l 2 to 5 times the background noise level of the instrument. I t is recommended that the LFB be f

ortified somewhe

re betwe en 0.1 to 0 .5 mg/L OC. All ava

ilable instrument digits are carried for the OCDL calculation. After completion of the OCDL, the calculation is rounded up or down a ccording to Standard Method 1050 B. 15 The final result is reported in units used for the TOC or DOC procedure and recorded to two sig nificant figures in the instrument log book. Calculate the OCDL using the e quation: Organ ic Carbon Detecti on Lim

it = St ( n - 1, 1 - alpha = 0.99) where:

t (n-1,1-alpha = 0.99)

= Student's t value for the 99% confidence le vel with n-1 degrees of free dom (t = 3. 14 for 7 r eplicate s) n = number of replicates, and S = standa

rd devia tion of re plicate a naly ses. If the initial O CDL exceeds 0.3 5 mg/L or the me an recovery

of the L FB used in the OCDL

determination exce eds + 50% of the true value, then the OCDL determination must be repeated.
9.3 INI TIAL

DEMONSTRATION OF CAPAB ILITY FOR DOC DETERMI NATION
9.3.1 Perform Sections 9.2.1 through 9.2.4 as prescribed for T OC.
9.3.2 INI TIAL

DEMONSTRATION OF F IL TER MEMBRANE SUITABI LI TY - Filter membranes are capable of affecting DOC and UVA a nalyses either by desorpti on (leac

hing) of DOC and U

V-absor bing mat erials f rom the fi lters to415.3 - 26 the sample s, or by

adsorpti on (uptak

e) of DO C and UV- absorbin g mater ials from the samples onto the filters. Filter membranes selected f or DOC and UVA measurements must not desorb nor adsorb significant DOC and UVabsorbing materials. Desorption is minimized by pr e-washing selected filters as described in Section 9.3.2.2. Adsorption is minimized by filtering a portion of the sample to waste before sample collection as desc ribed in Section 9.3.2.3. Because the filtration of relatively turbid samples may causefilters to clog, prefiltration may be nec essary a nd pre-filter preparation is described in Section 9.3.2.1. Due to the possibility of lot-to-lot variations in the levels of contamination or adsorption, it is recommended that for each filter lot, the user determine the amount of LRW needed to wa sh the filters and the amount of sample tha

t needs to be filter ed and dis carded

prior to c ollection

of filtra te (filter -to-was te volume ). A minimu m of three

filters ( from ea

ch new lo t) should be cleaned and checked for de sorption/adsorption prior to using the filters for actual samples. This evaluation must be repeated whe n filters are purchas ed from a

nother ma

nufactu rer or w hen the ty pe of filt er being used is changed.
9.3.2.1 PRE-FIL TER PREPARATION - I f the analyst a nticipates that the UVA and DOC sample will clog the 0.45-μm pore size filter membrane before enough filtrate ca

n be collected, glass fiber pre- filters without organ ic binders may

be used. Karanf

il et al 10 suggested cleaning the pre-filter by

heating to 550 °C for one hour, cooling to room temperature, then washing it with 500 mL of LRW. A 25-mL f

ilter-towaste volume (Sect. 9.3.2.3) was also recommended. The pr e-filters must be demonstrated as acceptable using the pr ocedures described below in Sections 9.3.2.2 and 9.3.2.3. Depending on the design of the filter apparatus, the analyst may be able to insert a pre-filter into the filter apparatus. The pre-filter and f ilter apparatus could then be washed as a unit, following the procedure in Sec tion 9.3.2.2. Prefilter adsorption and desorption may a lso be tested separately

from the filter membrane.
9.3.2.2 FILTER CLEANI NG - UV-absorbing materials and DO C are removed from the filter and filter apparatus by passing LRW through the filter. The volume of LRW required depends on the ty pe and disc size of the filter. For the filter apparatus used to g enerate the data in this method, three successive rinses of 250 mL each (for a total of 750 mL ) removed UV-absorbing materials and DOC that could leac h from the filter and appara tus. (The Karanf il 10 study found that a 500 mL wash was sufficient to prepare the 47-mm disk filters recommended in their study for DOC samples and a wash of 100 mL was sufficient for filters used solely to prepare

UVA samples.) Acceptable cleaning is demonstrated by a naly zing filte r blanks ( Sects. 11. 4.3, 11.6) and meet ing the c riteria415.3 - 27 in Section 9.9. The volume of LRW required to obtain acce ptable filter blanks is then used to

clean f ilters for analy

ses of al l samples ( Sect. 11.4). F ilters tha

t cannot b e cleaned to meet the ref erence d criter

ia must not be

used in the

prepar ation of D OC and UV

A samples

. 9.3.2.3 FIL

TER-TO- WASTE VOL

UME DETERMINA

TION - In o rder to minimize the loss of sample onto the filter by adsorption, a portion of the sample must be used to saturate the adsorption sites on the filter after it is cleaned according to

Section 9. 3.2.2. The

amount of

sample filtrate that must be discarded prior to collecting filtrate f or DOC and/or UVA analy ses will vary depe nding upon the type

and size of filter and the volume should be minimized in order to prevent filter clogging. A 25-mL filter-to-waste volume wa s recommended when using the hydrophilic poly

ethersulfone and hy

drophilic polypropy

lene filters of 47-mm disc

size studie d by

Karanf il et al 10 based on evaluations using low-turbidity model waters pre pared from preconcentrated humic a nd fulvic materials. In this method, a low-turbidity (i.e., TOC = DOC) finished water sample can be used in the filter-to-waste deter mination. For laboratories that are analy zing samples from a variety of sources, the selected water should have a TOC conce ntration in the range of 1 to 3 mg/L. For labora

tories that only analy

ze samples from one source, the selecte d water should be a finished water with the low est TOC tha t is generally observed (NOTE: Depending on the quality of the source water, this could be water with a TOC concentra tion much higher than the 1 to 3 mg/L recommende d for laboratories that are analy zing samples from a variety

of sources.) A series of at least three filtrates are collected in separate containers for the filte r-to-wa ste volume

determination. The

volume of

each fi ltrate is determined based on the minimum volume required to make an analytical de

termination. For example, if the DOC analy sis requires 30 mL, then a series of at lea st three successive 30-mL f iltrates should be collected. For UVA, three succe ssive 10-mL filtrates can be c ollected. If DOC and UVA ana

lyses are to be

performed on the same filtrate, then the volume of each filtrate should be adjusted to provide the minimum volume necessary to ac commodate both analyse s (in the above example, three successive 40-mL washes). Each filtrate is analy

zed according to the procedure in Section 11 and the concentration is compared to the concentra tion of the unfiltered sample. When the concentration of the filtrate is within ± 15% of the concentration measured in the unfiltered sample, then the r ecommended415.3 - 28 filter-to-waste volume is the sum of the volumes of that filtrate and any previous filtrate s in the se

ries. For example, if the unf iltered s ample has a TOC

concen tration of 3.5 mg/L and the f iltrate s eries (e ach filtr

ate = 30 mL) have conc entrations of 2.3, 3.2, and 3.4 mg/L, then a minimum of 6 0 mL of

sample should be fi ltered- to-waste prior to collecting filtrate for DOC analyses. It is recommended that the filterto-waste volume be determined by performing this test on at least three filters from each lot and averaging the results. Filters that require large volumes of filter-to-waste should be avoided , becau se they will be more subject to clogging pr ior to the collection of the necessary volume of

filtrate for ana lys is. The fi lter-to-waste vo lume that i s determined in this section must be used in the filtration procedure described in Section 11.4.4.
9.3.3 Perform Sections 9.2.5 through 9.2.7 using filtered L FBs. The LF Bs must be prepared using the same proce dure used to prepare samples (Sect. 11.4).
9.4 INI TIAL

DEMONSTRATION OF CAPAB ILITY FOR UVA DETE RMINATI ON
9.4.1 INI TIAL

CHECK OF SPECTROPHOTOMETER PERFORMANCE - The UV Spectrophotometer must be checked annually for 0 % transmittance, wavelength accurac

y, stray radiant energy, accuracy

and linearity, and optica

l alignment. It is recommende d that the instrument performance be verified th rou gh t he m anu fac tu rer or a sci ent ifi c in st rum ent ser vi ce c om pan y. If independent verification of performance is not feasible, the laboratory may acquire a certified spectrophotometric f ilter set and conduct the evaluation. Waveleng

th verifi cation is made using certifi ed spect

rophotome

tric filte r sets with values traceable to NI ST. Using the filter set, test two wavelengths betwee n 220 and 3 40 nm. The

instrumen

t perfor mance sh ould be re corded i

n the instrument log and be used to monitor the spectrophotometer perfor mance over time. Follow the instrument manufacturer’s opera tion manual when measurin g the ac ceptabl e wavel ength tr ansmittan ce limits.
9.4.2 Verify the

spectrophotometer performance ac cording to the procedure as outlined in Section 10.4.
9.4.3 Conduct the filter membrane suitability study described in Section 9.3.2 for UVA.
9.5 CONTINUI

NG CALI

BRATION CHECK (CCC) - With each ana lysis batch, analy

ze a Low-CCC at or below the MRL (Sect. 9.10) prior to TOC or DOC sample analysis. Subsequent CCCs are analyzed af ter every ten samples and after the last sample. The concentrations should be rotated to cover the instrument calibration range. A MidCCC is required during every analysis batch. Ac ceptance criteria are a s follows: Low-415.3 - 29 CCC, + 50% of true value; Mid-CCC, + 20% of true value; High-CCC, + 15% of true value, se e Section

10.3 for c oncentr

ations.
9.6 FIELD DU

PLI CATE (FD ) - Within e ach ana lys is batch, a minimum of one set of

field duplicates must be analyzed (F D1 and FD2). Sample homogeneity and the chemical nature of the sample matrix can affect analy te recovery

and the quality of the da

ta. Duplicate sample analy ses serve as a check on sampling a nd laboratory pr

ecision. Two samples are collected at the field site and ar e treated exactly

alike.
9.6.1 Calculat

e the re lative pe

rcent di ffere

nce (RPD)

for dupli cate me asureme nts (FD1 and FD2) using the equa tion:

9.6.2 Relative percent difference f or field duplicates having an avera ge concentration of > 2 mg/L OC should fall in the rang e of < 20% RPD. If f ield duplic ates in this concentration range exhibit an RPD greater than 20%, results should be flagged and the ca

use for the greater diffe

rence (e.g. incomplete IC removal or matrix interference), investigated. UVA re adings should be < 10% RPD. NOTE: Greater variability may be observed for samples with OC approaching the OCDL.
9.7 LABORATORY FORTI FIED BL ANK (LFB ) - Within each DOC analy sis batch, analy ze an aliq uot of re agent water or

other bla nk matrix wh

ich has be en fortif

ied with KHP at a concentration of 1-5 mg/L OC. Recovery f

or the LFB must be within ±20% of the true value. One L

FB is required with each DOC analy sis batch. For the DOC analysis, an L

FB is subjected to the same preparation and a nalysis as a sample, including filtration (Sect. 11.4). The L FB is not determined for the TOC or UVA measure ments. 9.8 LAB ORATORY F ORTIFIED MATRI X (LF M) - Within e ach TOC or DOC ana lys is batch, a n aliquot o f one fie ld sample i s fortifi ed with an aliquot of

the OC-PD S (Sect. 7.8.3). The spike concen tration us ed should re sult in an increase in t he LFM concentration of 50 to 200% of its measured or expected conc entration. Over time, samples from all routine sample sources should be fortified. For DO C analysis, the LFM i s filtere d prior to

acidific ation and

analy sis.
9.8.1 Calculate the percent spike recovery (%REC) using the equation:415.3 - 30 where A = measu

red conc entration in the fortified s ample B = measured concentration in the unfor tified sample, and C = fortification concentration.
9.8.2 Recoveries may

exhibit a matrix dependence. If the L FM recovery

falls outside of 70 to 130% for any

fortified concentration, the analy st should suspect that inorganic carbon was not properly removed (Sect. 11.5) from the sample or that contamination or matrix interference exists (Sect. 4) and can not be removed. If the source of the

poor recovery

can not be identified, the analyst should label the sample report “suspect/contamination or matrix interference” to inform the data user that the sample data quality is questionable but should not be rejected. Failure to meet the recovery criteria after repeated sa

mpling may sug

gest that th e s am pl e m at ri x m ay n ee d f ur th er st ud y. 9.9 LAB ORATORY RE AGENT B LANK

(LRB ) AND FI

LTER B LANK

(FB) - Within each analy sis batch, a minimum of one LRB must be analy zed. For DOC and UVA analysis, the FB serves as the LRB. If more than one lot of filters is used in a DOC or UVA analy

tical batch, a FB must be analy zed for each lot. The analyst should be aware that addi tional fil ter blan ks, up to one for ea

ch sample , are re quired by some regulations (e.g., 40 CFR 141. 131(d) (4)( i) ). The LRB or FB is used to assess contamination from the laboratory environment and background contamination from the reagents used in sample processing and is treated exactly the same as a samp le. The v olume of the FB mus t be the sa me as the sample volume. If UVA is to be determined, the FB (UVA-F B) must have an absorbance of < 0.01 cm -1 UVA. The LRB and/or the FB (DOC-FB) must be < 0.3 5 m g/L O C. If 0.35 mg/L OC or 0.01 cm -1 UVA is exceeded, background ca rbon or reagent contamination should be suspected. The cause for signific ant changes in the L RB or FB value must be identified and any determined source of contamination must be eliminate d. For th e FB, th is may mean re determination of f ilter membrane sui

tability (Sect. 9.3.2). The cause of the contamination and the cor rective action used to remedy the problem is then recorded in the instrument log for future reference.
9.10 MINI

MUM REPORTING LEVEL (MRL) - The OCDL should not be used as the MRL. For TOC analy

sis, it is recommended that an MRL be established no lower tha n the mean LRB measure

ment plus 3 F , or two times the me an LR B measu rement, whichever is greater. F or DOC analysis, the F B is substituted for the LRB. This value should be calculated over a period of time, to refle ct variability in the blank measurements. Although the lowest calibration standard for OC may be below the MRL, the MRL for OC must never be established at a concentration lower than the lowe st OC cali

bration st andard.415.3 - 31

9.11 QUALITY CONTROL SAMPLE ( QCS) - During the analysis of the IDC (Sects. 9.2, 9. 3) , e ac h t im e n ew OC -P DS so lu ti on s a re pr ep ar ed (S ec t. 7. 8. 3) , o r a t l ea st qu ar te rl y, analyze a QCS from a sour ce different from the source of the calibration standards. The QCS is used to provide an independent verification of the method and the TOC instrument system. To verify the stock or calibration solutions by compar ison with the QCS, dilute the calibration solution and QCS to a concentration in the mid range of the calibration curve (approx. 1 - 5 mg/L TOC) in the same manner that the OC-CAL standards are made (Sect. 7.8.4). Acc eptable verification of the calibration is made when t he mean s of 3 a nalyses f or bot h the c alibr ation solu tion and QC S, hav ing a concentration range betwe en 1 to 5 mg/L OC, ag ree to within ±20% of the true value. If the measured Q CS concentration is not within ±20% of the true value, the calibration solution must be remade and/or the source of the problem must be determined and corrected. Analy sis of the QCS only applies to TOC and DOC determination.
9.12 SPECTROPHOTOMETER CHECK REQUIREMENT - The performanc e of the spectrophotometer is initially demonstrated using the procedure in Section 9.4.1. The day-to-day

perfor mance of the spectrophotometer is c hecked using KH

P-SCS (Sect

. 7.10) or a commercially

available SCS (COMM-SCS, Sect. 7.9) according to the procedure in Section 10.4.
10.0 CALIBRATI ON AND STAN DARDIZ ATION
10.1 INSTRUMENT SET UP AND OPTI MIZATION - Prior to calibrating the TOC inst rumen t, cle an the inst rumen t system with carbon diox ide fr ee wate r and s parge reagents with ultra high purity reagent gas as spe cified by the instrument manuf acturer to remove

backg round ca rbon dioxide . NOTE: TOC Instrum ent 1 does not requir

e reagent gas for operation . Monitor the instrume nt backg round ca rbon dioxide

levels for at least 30 minutes or until the background signal re aches the manufacturer’s recommended level. The instrument should have a stable bac kground and be free from drift ca used by CO 2 contaminated gas or leaks in the sy stem. Adjust instrument temperature, reagent g as and reagent pump flow settings ac cording to the manufacturer’s operation manual. Some instruments may require reagent priming

runs to clean the flow injection sy stem and reduce carbon backg round. After the instrument is judge d to be sta

ble, load the auto- injector

or prepa re to man ually inject fo ur LRB samples a nd start the analy

sis. The da

ta collec ted from t he first i njection of LRB is discarded and is considered a sy stem cleanup blank. The next three LRB injections should pro duce consecutiv e readi ngs that fall withi n 20% of their mean . If t hese conditions are met, the instrument is ready for calibration. If not, use the OC-CAL-1 standard and repeat this section. I f the three injections of OC-CAL-1 do not pr oduce consecu tive rea dings tha t fall with in 20% of t

heir mea n, the inst rument is n

ot ready to operate and maintenance must be perfor med according to the instrument operation manual before proceeding.415.3 - 32

10.2 CALI

BRATION CURVE - A ne w calibration curve is genera ted when fresh standards are made (Sect. 7.8.4) or when CCCs fall out of QC limits (Sect. 10.3). Use a CB and at least four OC-CAL standards tha t span the concentration range of the samples to be analyzed . For ex ample , if th e samp les to be anal yzed are l ow in c oncen trati on (a ra nge falling between 0.5 to 5 mg/L OC), prepare a calibration blank and a minimum of four TOC calibration sta

ndards ( CB, OC-CA

L 1 - 4 , see Sect. 7.8.4). The lowe st concentration calibration standard must be at or below the MRL , which may depe nd on system sensitivity . Add an additional 40 μL of H 3 PO 4 , HCl, or H 2 SO 4 , depending upon instrument requirements (Sect. 8.0), to the 40-mL injec tion vial(s). Sparge the calibra tion stand ards usin g the I C removal

procedu re in Section 11.5 pr

ior to calibrating the instrument. Inje ct the standards from low to high concentration and calibrate the instrument. Be caref ul not to extend the calibration range over too wide of a conc entration rang e as flow injection memory may cause a naly tical er ror (Sec t. 9.2.3). The optional OC-CAL 6 - 7 may be used when operating the instrument in a higher concentration rang e. NOTE: For instrum ents that h ave an int ernal cal ibration se tting, the c

alibration i

s checked by comparing the five point calibration curve with the internal calibration point. If the five point calibration curve does not agree with the internal calibration using the CCC criteria in Section 10.3, the internal calibration of TOC instrument must be reset by the manufacturer or adjusted by the analyst, following the manufact urer’s op eration ma nual.
10.2.1 With the instrument in the ready mode, initiate the automated instrument calibration routine as per the instrument manufacturer’ s operation manual. The computer generated c alibration curve must have r 2 $ 0.993 before proceeding with analy

ses. Ideally

the instrument calibration should be r 2 $ 0.9995 for best results. After the instrument sy stem has been calibrated, verify the c alibration using the Continuing Calibration Check (CCC, Sect.10.3) and QCS (Sect. 9.11).
10.2.2 Save the data from the initial calibration curve and rec ord it in the laboratory notebook or instrument log. The initial calibration curve serves as a historical reference so that future ca librations curves can be compared to determine if the slope or sensitivity of calibration has c hanged. If

the slope or sensitivity of the instrument changes such that QC requirements cannot be met, consult the instrument manual or lab SOP for corrective action, which may include instrument maintenance and recalibration.
10.3 CONTINUI

NG CALI

BRATION CHECK (CCC) - Demonstration and doc umentation of continuing calibration is required and must meet the require ments listed below. The CCC solutions are made up weekly or just prior to a sample run and are prepared in the same manner as the OC-CALs ( Sect. 7.8.4). An analy sis batch begins with the analysis of a L

ow-CCC. CCCs are analyzed ever y 10 samples and must also include a415.3 - 33 Mid-C CC. S ubseq uent C CCs s houl d alte rnate b etween low, m edium , and h igh concen trations, and must e

nd the ana

lys is batch. In su

mmary , at leas t one L ow-CCC and one Mid-CCC is analyzed with each a nalysis batch in order

to verify the calibration curve. It is re commended that low, mid, and high CCCs be used to verify the calibration curve over time.
10.3.1 Low-CCC - the concentration range may vary fr om as low as 2 times the OCDL up to 0.7 mg/L

OC. The Low-CCC is used to verify the low end of the calibration and must be at or below the MRL, whic h may depend on sy

stem sensitivity. The recove

ry for the L

ow-CCC must be within +50% of the true value.
10.3.2 Mid-CCC - the concentration is varied between 1.0 mg /L to 5.0 mg/L

OC. The purpose of this CCC is to verify the pre cision and accuracy at the calibration range where c ritical source water treatment decisions are made. The Mid-CCC concentration may be varied to meet changing re gulatory req ui rem ent s. T he M id -ra nge CC C m ust be w it hi n ±2 0% o f th e tr ue v alu e. If it is not, the TOC instrument system must be recalibrated.
10.3.3 High-CCC - the concentration range is var ied between 5 to 50 mg/L OC. The selection of the H igh-CCC sh ould be ne ar the c oncentr ation of the highe st OCCAL standard used. The purpose of this CCC is to bracket the concentration the samples that are ty

pically analy

zed and to verify the uppe r range of the calibra tion curv e. High -CCC must be within ±15%

of the tru e value. If it

is not, the TOC instrument system must be recalibrated.
10.4 SPECTROPHOTOMETER PERFORMANCE CHECK - The performance of the spectrophotometer is initially demonstrated using the procedure in Section 9.4.1. The day-to-day

perfor mance of the spectrophotometer is c hecked using KH

P-SCS (Sect

. 7.10) or a commercially

available SCS (COMM-SCS, Sect. 7.9) prior to analyzing any UVA samples using the procedure desc ribed below.
10.4.1 Using a transfer pipet fill the spectrophotometer c ell with the COMM-BKS or KHP-SCS-BLANK (Sects. 7.9.1, 7.10.1). Use this solution to zero the spectrophotometer.
10.4.2 After the spectr

ophotomet

er is zero ed, empty

the cell,clean with LRW, rinse with methanol, dry with N 2 or reag ent gra

de air, a nd fill it wi

th the KHP- SCS or COMM-SCS.
10.4.3 Read the

UVA of th e KHP-SCS or COMM-SCS. The readi ng must be

within 10% of the

expected absorba nce valu e. Recor d the absorbance

of the KH

PSCS or COMM-SCS in the spectrophotometer instrument logbook. Empty the415.3 - 34 cell, clean with LRW, rinse with methanol, and dry with N 2 or reagent gra

de air.
10.4.4 If the SCS absor

bance c riteria stated a bove ca nnot be me

t, discard the COMMSCS or the KH

P-SCS and pu

rchase new COMM- SCS or rema ke the KH

PSCS. Repeat Section 10.4.
11.0 PROCEDURE
11.1 TOC/DOC SAMPLE INTEG RITY EVAL

UATION - I

t is important to analyze a TOC or DOC sample as directly and as soon as possible. Sample handling and preparation should be m

inimized. U

pon rece iving the

sample fr

om the fie ld, the analy st must determine if the sa

mple was t

reated and store d accor

ding to in struction s found in Section 8.
11.2 OPTI ONAL

TREATMENT FOR TOC/ DOC SAMPL

E MATRI

X LOSS - Aquatic humic substances precipitate at pH below 2 16 , and may move to glass vessel walls or instrumen t tubing. If the analy

st suspec ts that humic substances have precipitated (which sometimes oc curs in bl ackwat ers) 14 or flock

ed to the b ottom of the

sample container, the sample is degassed by sparging to remove I C as directed in Section 11.5. The sample is then split into two portions. One portion is left at a pH # 2, and the pH of the second portion is adjusted to pH 5 to 7 in order to increase the solubility of hydrophobic matter in the sa mple. Both samples are allowed to sit capped for 1⁄2 hour before further sample processing . These samples are treated in the same manne r as field duplicates (FD), Section 9.6. The results of both split samples and corre sponding pH values should be reported to the data user.
11.3 TOC SAMPLE PREPARATION - Remove the TOC sample from cold storage and allow the sample to come to room temperature. Determine if the sa mple has been preserved by

acidification to a pH # 2 by placing some drops on pH paper or by pouring some of the sample into a small beaker and che cking it with a glass or solidstate pH electrode. Do Not put the pH paper or electrode into the sample bottle. I f the pH is greater than 2, discard the sample.
11.3.1 TYPICAL

TOC SAMPLE PRE-TREATMENT - Samples that appear to be low in par

ticulate and suspe

nded mate

rial are gener ally transfe rred dir ectly to the 40-mL injection vial. I f the sample appears to contain sediment or floating material, allow the sample to sit for a minute or two to allow sediment material to settle back to the bottom of the bottle. After allowing the sample to settle, transfer the sample from the middle of the bottle using a disposable pipet to the injection vial. Add 40 μL of H 3 PO 4 , HCl, or H 2 SO 4 depending upon instrument require ments (Se ct. 8.0) t

o the 40-m

L inje ction via

l and labe l it.
11.3.2 Proceed

to Section

11.5, for IC re moval.415.3 - 35

11.4 SUVA SAMPL

E PREPARATI

ON - I f SUVA is not being determined, proc eed to Section 11.5. The SUVA determination consists of paired sample analy ses composed of a DOC sample and a UVA sample. DOC and UVA sa mples may be taken f

rom the same bottle, or may be

taken from separate field duplicate bottles. Remove the DOC and UVA sample(s) from cold storage and allow them to come to room temperature. The laboratory

is required to document any use of alternative filters, apparatus (see note, Sect. 6.1), or changes in the SUVA sample pre paration procedure. All QC require ments (Se ct. 9) mus t be met.
11.4.1 Samples for DOC and UVA analysis are NOT acidified in the field. The DOC sample is a

cidified after f iltration as descr ibed below and the

UVA samp le is not acidified at all. Determine if the sample(s) was ac cidentally prese rved by placing a few drops from the sample on pH pa per or by pour

ing some of the sample into a small beaker and checking it with a glass or solid-state pH electrode. Do Not put the pH paper or electrode into the sample bottle. Placing the pH paper or electrode into the sample bottle will contaminate the sample solution with organic carbon. I f this happens, the sample must be discard ed. I f the UVA

sample pH

is # 2, check to make s

ure that the sample

is actually for

the UVA determination. It is possible that this sample is a TOC or filtered DOC sample and was mislabeled as a UVA sample. I f the sample set was not mislabeled or switched but accidentally preserved, the sample must be discarded. The analyst must check the date and time of collection to ensure that the sample holding times listed in Section 8.1 have been met.
11.4.2 Filter Cleaning - Cleaning the filter a pparatus, including the filter, removes trace organic compounds that may have been left behind in the manufacturing process. This cleaning must be done immediately prior to sample filtration. Rinse the filter with LRW, using the cleaning pr ocedure used to determine filter membrane suitability (Sect. 9.3.2.2), including the cleaning of the prefi lt er if a p re -f il te r i s n ec es sa ry. 11.4.3 Filter Blank (FB) - Use a clean filter apparatus (prepa red in Sect. 11.4.2) and filter an aliquot of LRW into an injection vial for the DOC analy sis and another aliquot of LRW into a vial for UVA analy sis (Figure 1). FB volume must be the same as the sample volume collected in Section 11.4.4. During the development of this method, approximately 250 mL of LRW was filtered and aliquots were poured into two 40-mL injection vials and labe led as the DOC and UVA F Bs. I f the DOC a nd UVA analy ses are

coming f rom two se

parate bottles, a filter apparatus will be needed for ea ch bottle and an FB should be prepared from each appa

ratus. Add 40 μL of H 3 PO 4 , HCl, or H 2 SO 4 (as required by the variou s instrum ent types, Sect. 8. 0) to the 40 -mL DOC-FB injection vial. Do not

acidi fy the UVA-FB injection vial. These vials are paired with the respective SUVA sample and retaine d for DOC-FB and UVAFB ana lys es.415.3 - 36 11.4.4 Sample Pre

paration - Reasse

mble the f

ilter app aratus. Pour enou gh sampl e onto the filter to saturate any adsorption sites, as determined according to the filter- to-waste

procedu re in Section 9.3.2. 3. Apply vacuum un

til no visibl e water r emains on

the filte r. Remove

the vacu um, swirl the appar

atus with sample fi ltrate, d

isassembl e, and dis card the sample fi ltrate r

inse. Rea ssemble the filter apparatus and pour an additional aliquot of sample into the top of the filter apparatus. Attach the vacuum and reta in the filtrate. Pour one aliquot into a 40-mL injection vial and label it to identify it as the DOC sample. Pour a second aliquot int

o a 40-mL

injection vial and l abel it to identify it as the UVA sample. Add 40 μL of H 3 PO 4 , HCl, or H 2 SO 4 to the 40-mL DOC injection vial. Do not

acidi fy the UVA injection vial. As with the DOC and UV FBs (Sect. 11.4.3), separate f ilter apparatus may

be used for the DOC and UVA samples, in which case the filtrate need not be split into two aliquots. For a sample that is difficult to filter, an additional filter apparatus or the optional pre-filter insert apparatus may be used. The use of additional filters may require

the collection of additional FBs, collected as specif ied in Section 11.4.3. The resulting additional DOC-FB, UVA-F B sample filtrates are collected, their volumes composited and then placed into their respective injection vials.
11.5 INORGANI C CARBON REMOVAL - All OC-CA Ls, TOC and DOC samples , DOC-FBs, and LRBs must be treated to rem ove IC prior to OC analysis. UVA samples and UVA-FBs are not sparged with nitrogen gas or otherwise treated to remov e IC prior

to analysis

(See Figure 2). The labora tory is required to doc

ument any u se o f al ter nat iv e IC r emo val app ara tu s (S ect s. 6 .9, 11. 5.2 ) or cha nge s i n t he IC removal procedure. All quality control requirements (Sect. 9.2.4) must be met. NOTE: If a spargi

ng apparat

us is used, it should be

isolated fr

om the org

anic laboratory and be free of organic contaminants.
11.5.1 CLEAN

ING SPARGI NG APPARAT

US: Before initia

l use and i

mmediate ly after each use, the sparging apparatus must be cleaned. With the nitrogen turned off, dip the stainless steel needles in a 40-mL injection vial containing di lu te a cid (40 μL H 3 PO 4 , HCL, or H 2 SO 4 per 40 mL L RW). Take the needles out of the dilute acid and turn the nitrogen back on to flush out any residual dilute ac id. If

disposabl e pipette s are use d as part of the spa

rging appara tus, discard the pipettes after each use instead of attempting to clean and reuse them.
11.5.2 SPAR GING PRO CEDUR E: Su bmerge t he app aratus needl es use d to s parge the sample s near the bottom of the 40-mL

sample inj ection vi al. Data generated for this method were generated by externally sparging the acidified samples w

ith nitrog en gas , at 100 to 2 00 mL/ minute, for 20 minute s per 40- mL sample inj ection vi al. Some in strument c ompanies provide o

ptional inorganic415.3 - 37 carbon removal apparatus that may produce an efficient means for the r emoval of IC. The laboratory

must demonstrate sparging efficienc y by the performance of the I C removal

spargi ng eff iciency test (Sect. 9.2.4 ) a

nd meetin g the L RB requirements as stated in Section 9.9.
11.6 SAMPLE ASSAY
11.6.1 TOC/DOC Sample Analysis - This is accomplished by placing into the injection vial tray a serie s of 40-mL

injection vials usua

lly c ontaining

any or all of the fo llowing t

ype s of sample s: LRB , DOC-FB , CB, OC-C AL(s ), CCC s (Low, Mid or High conc entration), field samples, FD1 & FD2, L RB between samples if needed as specified in Section 9.2.3, L FB, LFM, a

nd the QCS. The DOC-FB maximum allowable bac kgroun d conce ntration i s 0.35 mg/L OC. The injection tray is plac ed into the instrument, the run is initiated, and the results of analyse s are recorded.
11.6.2 UVA ANA

LYSES - If the spectr

ophotomet

er perf ormance meets the

SCS absorbance criteria as stated in Section 10.4, zero the instrument with the empty cell. Next fill the cell with the UVA-F B and read the absorbance . The UVA-FB ’s maximum a

llowable backg round ab sorbanc e is 0.01 cm -1 UVA . If 0.01 cm -1 UVA for the UVA-FB is exceede d, the cause must be identified and any deter mined source of contamination must be eliminated. The spectrophotometer performance must then be re checked (Sect. 10.4). The laboratory should also c

heck the initial zero each time 10 samples have been read. Rinse the spectrophotometer cell with a small amount of the UVA sample or UVA-FB by

directly pipetting or

pouring the sample into the spectrophotometer cell and discarding the r inse. Refill the spectrophotometer cell, ca refully clean the cell wi

ndow, and

place in the spectrophotometer ce ll holder. Alternatively , flow cells maybe used, filled and flushed as needed. Measure the UVA and record. If field duplicates are collected, the FD 1 & FD2 sample filtrates are also read and re corded.
12.0 DATA ANA

LYSIS AND C ALCULATION
12.1 TOC DIRECT READI NG: The TOC concentration is calculated by the automated instrument system’s software. F ollow the instrument manufacturer’s operation manual when making instrument response adjustments for instrument system blank correc tions. The

TOC calc

ulation a ssumes tha

t the sampl e has bee

n proper ly preserved, that only

a trace amount of I C remains following the IC remova l procedure, and that any re

maining IC will not contribute to the TOC measurement a nd result in a calculation error. Some instrument sy stems calculate TOC from the difference of the total car bon (TC) m

inus the IC. The ana

lys t is remind

ed that th e IC i

n the samp le is removed prior to sa

mple ana lys is. There fore, the repor ted TC is eq

ual to, an d the same415.3 - 38 as, the TOC value (TOC =TC) and is read directly from the instrument’s computer or printout.
12.2 SUVA CALCUL

ATION: Follow the instrument manufac turer’s operation manual instructions when making instrument response adjustments for instrument system bl ank cor rec ti on. As i n t he a bov e TO C ca lcu lat io n, t he a nal yst i s re mi nde d t hat th e IC of the DOC sample is removed prior to analysis. After filtration, the TOC instrument value is e qual to the

DOC. The S UVA is the n calcul ated fr

om the DOC &

UVA data that results from the procedure as described a bove (Sects. 11.6.1, 11.6.2). The UVA of the sample in cm -1 is divided by the DOC of the sample, multiplied by 100 cm/M and either r eported in units of L

/mg-M or as “SUVA”. The SU

VA is cal culated

as follow s: SUVA (L/mg-M) = U

VA(cm -1 ) / DOC (mg

/L) * 100 cm/M UVA Calculation: UVA = A /d where:
UVA = The calc ulated UV

absorba nce of the sample

in absorbance units (cm -1 ).
A = The measured UV absorbance a t 254 nm of the sample that is filtered through a 0.45-μm filter media. d = The quar tz cell pat h length in cm.
NOTE: A Filter Blank (FB) is used to monitor background carbon contamination (Sect. 11.4.3) and is not subtracted from the DOC and UVA meas urement

s. 12.3 Calculations should utilize all available digits of precision, but final reported concentrations should be rounded to two significant figur es (one digit of uncertainty ). The final calc ulation i s rounded up or down accordi ng to Standar d Method 1050B. 15
13.0 METHOD PERFORMANCE

NOTE: Data pres ented in S ection 17 are from si

ngle-lab oratory de terminati ons. All available digits were

used for calculation

and the ca lculations

were roun ded prior t

o entry in th e tables. The data we re report ed to as ma ny as thre e significant figure s to give the reader a better understanding of method performance.
13.1 Table 17.1 summarizes the 3-day organic carbon detection limit (OCDL ) study for five TOC instru

ments sy stems. The

DOC dete

rmination range d from 0.0 2 to 0.08 mg /L OCDL and the TOC determination ranged from 0.04 to 0.12 mg/L OCDL . All source415.3 - 39 water samples reported in Section 13 and the Section 17 Tables wer e sparged for 20 minutes to r

emove inorganic

carbon i nterfe rences
. 13.2 Table 17.2 and associated sub-tables illustrate the single instrument precision and accura cy for eac h of the f ive TOC ins trument te chnologies.
13.3 Tables 17.3 and 17.4 illustrate the instrument differences and per formances for five TOC instru

ments ana

lyzin g seve n differ ent sourc e water

matrice s. 13.4 In all cases, the TOC instruments had diffic ulty in analy

zing the Saint Leon well water. The Saint Leon well water ha d a moderately

high inorganic carbon conte nt of approximately 100 mg/L

IC, and a low orga

nic carbon content of 0.2 to 0.6 mg/L OC. The Saint Leon well water or ganic carbon content was nea r the organic carbon detection limit. The low OC concentration produced the gre atest differences between instrument responses. For low TOC samples with high I C, differences between instrument responses may be more apparent due to possible IC interf erence. 13.5 The TOC, DOC and SUVA procedures of this method are de pendent on the operation manual for the TOC instrument system a nd the UV spectrophotometer as provided by the respective instrument manufacturers. Howe ver, all performance criteria and quality control require

ments described in this method, as summarized in Tables 17.5 and 17.6, must be met

. 14.0 POLLUTION PREVENT ION
14.1 Pollution prevention encompasses any te chnique that reduces or eliminates the quantity or toxicity

of waste at the point of generation. Numerous oppor tunities for pollution prevention exist in laboratory operations. The EPA has e stablished a preferred hierarchy

of environmental management techniques that plac es pollution prevention as the management option of first choice . Whenever feasible, laboratory personnel should use pollution prevention techniques to address their waste ge neration. When wastes cannot be feasibly reduced at the source, the Ag ency re commends recyc ling as the next best option.
14.2 For information about pollution prevention that may be applicable to laboratories and resear ch institut ions, cons ult Less is Better: Laboratory Chemical Management for Waste Reduction , available from the American Chemical Society 's Department of Government Relat

ions and Sc ience Pol icy , 1155 16th Street N. W., Washing

ton D.C. 20036, (202)872-4477.
14.3 For rec

yc le information, contact the US EPA, Pollu

tion Preve

ntion and Wa steWise program, http://www.epa.gov/wastewise/

.415.3 - 40

1. Glaser, J. A.; Foerst, D. L.; McKee G. D.; Quave, S. A.; Budde, W. L. Tra ce Analy ses for Wastewaters. Environ. Sci. Tech nol. 1981 , 15 (12), 1426-1434. 2. Benner, R.; Storm, M . A Critica l Evaluat ion of the Analy tical Bl ank Assoc iated wit h DOC Measurements by

High-Temperature Cataly tic Oxidation. Mar. Chem. 1993 , 41 , 153-160. 3. St and ard Met hod 591 0B: Ult rav io let Abs orp ti on M eth od. InStandard Methods for the Examination of Water and W astewater, Eaton, A. D.; Clesceri, L. S.; Greenbe rg, A. E., Eds.; American Public Health Association; Washington, DC, 1995; 19 th ed. 4. Aiken, G.R. Chloride Interfere nce in the Analy sis of Dissolved Organic Carbon by the Wet Oxidation Method. Environ. Sci. Tech nol. 1992 , 26 (12), 2435-2439. 5. Sakamoto, T.; Miyasaka, T. TOC Ana lysis Study

Confirming the Accuracy of a Method for Measuring TOC by

Wet Oxidation. Ultrapure Water 1987 , 24-31. 6. Potter, B. B.; Wimsatt, J. C. Preprints of Extended Abstracts, Vol 42 (1), 223 rd National Meeting of the American Chemical Society , Orlando, FL, April 7-11, 2002; Amer ican Chemical Society Division of Environmental Chemistry : Cape Girardeau, MO, 2002; Paper 60, 559-564. 7. Aiken, G.; Kaplan, L. A.; Weishaar, J. Assessment of Relative Ac curacy in the Determination of Organic Matter Conce ntrations in Aquatic Systems. J. Enviro n. Monit. 2002 , 4 , 70-74. 15.0 WASTE MANAGEMENT
15.1 The U.S. Environmental Protection Agency requires that laboratory

waste management practices be conducted consistent with all applicable rules a nd regulations. The Agency urges laboratories to protect the air, wa ter, and land by minimizing and controlling all releases from hoods and bench ope rations, complying w

ith the letter and spirit of a ny s ewer dis charg e permits and reg ulations, and by

comply ing with a ll solid and hazardous waste regulations, particularly the hazardous waste identification rules and land d

isposal re striction s. For fu rther inf ormation on waste ma

nageme nt, consul t The Waste Management Manual for Laboratory Personnel, available from the American Chemical Society at the address listed in Section 14.2.
15.2 The laboratory

should consult with local authorities prior to disposal of any wa ste to publicly owned tr eatment works (POT

W) and re ceive pe

rmission f

or that dis posal.
16.0 REFEREN CES415.3 - 41

8. American Chemical Society , Committee on Chemical Safety. Safety inAcademi c Chemistry Laboratories, Vol. 2, Accident Prevention for Faculty and Administrators, 7 th ed. ; American Chemical Society : Washington, DC, 2003. 9. Occupational Exposure to Hazardous Chemicals in Labora tories. Code of Federal Regulations , Part 1910.1450, Title 29, 2001

. 10. Karanfil, T.; Erdogan, I .; Schlautman, M. A. Selecting Filter Membranes for Mea suring DOC and UV 254 . J. Am. Water Works Assoc. 2003, 95 (3), 86-100. 11. St and ard Met hod 108 0: Rea gen t-G rad e W ate r. In Standard Methods for the Examination of Water and W

astewater, Eaton, A. D.; Clesceri, L. S.; Greenbe rg, A. E., Eds.; American Public Health Association; Washington, DC, 1995; 19 th ed. 12. Schaffer, R. B.; Van Hall, C. E.; McDermott, G. N.; Ba rth, D.; Stenger, V. A.; Sebesta, S. J.; Grigg s, S. H. App lication o f a Carbo n Analy zer in Waste

Treatme nt. J. Water Pollut. Control Fed. 1965 , 37 (11), 1545-1566. 13. Van Hall, C. E.; Barth, D.; Stenger, V. A. Elimination of Carbonates f rom Aqueous Solutions Prior to Organic Carbon Determination. Anal. Chem. 1965 , 37 (6), 769-771. 14. Kaplan, L.A. Comparison of Hig h-Temperature and Persulfate Oxidation Methods for Determi nation of Dissolved

Organ ic Carbon in Fresh waters. Limnol. Oc eanogr. 1992 , 37 (5), 1119-1125. 15. St and ard Met hod 105 0B: Si gni fic ant Fig ure s. In Standard Methods for the Examination of Water and W

astewater, Eaton, A. D.; Clesceri, L. S.; Greenbe rg, A. E., Eds.; American Public Health Association; Washington, DC, 1995; 19 th ed. 16. St and ard Met hod 551 0: Aqu ati c Hu mi c Su bst anc es. InStandard Methods for the Examination of Water and W astewater, Eaton, A. D.; Clesceri, L. S.; Greenbe rg, A. E., Eds.; American Public Health Association; Washington, DC, 1995; 19 th ed.415.3 - 42

17.0 TABLES, DIAG RAMS, F LOWCHARTS, AND VALID ATION DATA
17.1 ORGANIC CARBON DE TECTION LIMIT (OCDL) a

Dissolved O rganic Ca rbon (DOC) , mg/L

Instrum ent For t ified

Conc. b Mean

Recovered Conc. %RSD c %REC d OCDL

1 0.130 0.155 11 119 0.054 2 0.125 0.116 22 93 0.082 3 0.250 0.249 4 100 0.035 4 0.130 0.125 5 96 0.018 5 0.250 0.233 9 93 0.068

Total Orga nic Carbon (TOC), m g/L

Instrum ent Fo rt ifie d

Conc. Mean

Recovered Conc. %RSD c %REC d OCDL

1 0.130 0.159 14 122 0.071 2 0.125 0.145 26 116 0.118 3 0.250 0.259 8 104 0.061 4 0.130 0.130 9 100 0.036 5 0.250 0.251 7 100 0.059

a Organic Carbon

Detection Limits were determined by analyz ing 7 replicates ov

er 3 days. b LRW fortified as specified in the table.

c %RSD = percent relativ e standard deviation d %REC =

percen t recovery IN STRU MENT : 1: UV/Persulfate/Wet Oxidation w ith Permeation/Con

ductivity Detection 2: Elevated Tem

perature/Catalyzed/P ersulfate/Wet Oxidation/Nondispersiv e Infrared Detection (NDIR) 3: UV /Low Tempe rat ure/ Pers ulf ate /We t Oxi dat ion/ NDIR 4: Ca tal yzed/ Combu sti on Ox ida tio n(68 0 °C)/ NDIR 5: Hi gh Te mpera tur e Comb ust ion O xida tio n/ND IR415.3 - 43

17.2 SINGLE TOC INSTRUMENT PRECISION AND ACCURACY
17.2.1 TOC Instrument 1: UV/persulfate wet oxidation with permeation/conductivity detection

Dissolved O rganic Ca rbon, mg /L a

Source Water Unfortified Sample Conc. Fortified Sample Conc.
Mean %RSD Mean %REC Boulder Creek 1.63 1.62 12.2 105 Shingobe e R. 2.98 0.19 13.5 105 Bolten We ll 1.27 0.00 12.0 107 Ohio R. (Fernbank) 2.79 0.36 13.6 108 Muddy Creek 3.81 0.15 14.6 108 Great Mi ami R. 3.18 0.00 13.7 104 Saint L eon Well 0.53 0.97 11.0 104

Total Orga nic Carbon,

mg/L a

Source Water Unfortified Sample Conc. Fortified Sample Conc.
Mean %RSD Mean %REC Boulder Creek 1.73 0.33 12.1 103 Shingobe e R. 3.16 0.18 13.0 98 Bolten We ll 1.32 0.44 11.4 100 Ohio R. (Fernbank) 3.02 0.57 13.2 102 Muddy Creek 4.24 0.00 14.6 103 Great Mi ami R. 3.51 0.33 13.8 102 Saint L eon Well 0.66 0.52 11.1 104

a N = 3, samples fortifie d at 10mg/L OC using KHP415.3 - 44

17.2 SINGLE TOC INSTRUMENT PRECISION AND ACCURACY , cont’d.
17.2.2 TOC Instrument 2: Elevated temperat ure/catalyzed/persulfate wet oxidation/N

DIR

Dissolved O rganic Ca rbon, mg /L a

Source Water Unfortified

Sample Conc. Fortified Sample Conc.
Mean Mean %REC Boulder Creek 1.40 11.8 104 Shingobe e R. 2.58 13.3 106 Bolten We ll 1.04 12.6 105 Ohio R. (Fernbank) 2.41 13.3 108 Muddy Creek 3.25 14.3 110 Great Mi ami R. 2.68 13.4 107 Saint L eon Well 0.40 10.6 101

Total Orga nic Carbon,

mg/L a

Source Water Unfortified

Sample Conc. Fortified Sample Conc.
Mean Mean %REC Boulder Creek 1.38 11.2 98 Shingobe e R. 2.62 12.7 100 Bolten We ll 1.05 11.4 103 Ohio R. (Fernbank) 2.46 13.1 106 Muddy Creek 3.41 13.8 104 Great Mi ami R. 2.89 13.2 103 Saint L eon Well 0.38 10.5 102

a N = 2, samples fortifie d at 10mg/L OC using KHP415.3 - 45

17.2 SINGLE TOC INSTRUMENT PRECISION AND ACCURACY, cont’d.
17.2.3 TOC Instrum ent 3: UV /low tem peratur e/persulfa te wet oxi dation/NDIR

Dissolved O rganic Ca rbon, mg /L a

Source Water Unfortified Sample Conc. Fortified Sample Conc.
Mean %RSD Mean %REC Boulder Creek 1.52 1.81 11.5 100 Shingobe e R. 2.71 1.10 13.2 104 Bolten We ll 1.18 1.76 11.3 101 Ohio R. (Fernbank) 2.50 0.74 13.1 106 Muddy Creek 3.38 0.81 14.0 106 Great Mi ami R. 2.91 0.64 13.1 102 Saint L eon Well 0.56 0.88 10.7 101

Total Orga nic Carbon,

mg/L a

Source Water Unfortified Sample Conc. Fortified Sample Conc.
Mean %RSD Mean %REC Boulder Creek 1.47 1.77 11.2 97 Shingobe e R. 2.72 0.02 12.7 99 Bolten We ll 1.16 2.45 11.0 98 Ohio R. (Fernbank) 2.58 1.01 12.6 100 Muddy Creek 3.18 1.28 13.5 103 Great Mi ami R. 2.92 1.01 13.0 101 Saint L eon Well 0.45 1.57 10.7 102

a N = 3, samples fortifie d at 10 mg/L OC using KHP415.3 - 46

17.2 SINGLE TOC INSTRUMENT PRECISION AND ACCURACY, cont’d.
17.2.4 TOC Instrum ent 4: Ca talyzed, 680 °C com

bustion oxida

tion/NDIR

Dissolved O rganic Ca rbon, mg /L a

Source Water Unfortified Sample Conc. Fortified Sample Conc.
Mean %RSD Mean %REC Boulder Creek 1.54 5.75 11.4 98 Shingobe e R. 2.71 3.18 12.4 97 Bolten We ll 1.24 1.25 12.4 98 Ohio R. (Fernbank) 2.52 5.73 12.4 98 Muddy Creek 3.56 3.17 13.3 98 Great Mi ami R. 3.00 6.94 12.7 96 Saint L eon Well 0.38 27.4 10.1 98

Total Orga nic Carbon,

mg/L a

Source Water Unfortified Sample Conc. Fortified Sample Conc.
Mean %RSD Mean %REC Boulder Creek 1.46 2.86 11 100 Shingobe e R. 2.84 2.19 13 97 Bolten We ll 1.12 1.70 11 100 Ohio R. (Fernbank) 2.81 1.79 13 100 Muddy Creek 4.04 2.02 14 96 Great Mi ami R. 3.42 1.66 14 101 Saint L eon Well 0.28 7.64 10 100

a N = 3, samples fortifie d at 10 mg/L OC using KHP415.3 - 47

17.2 SINGLE TOC INSTRUMENT PRECISION AND ACCURACY, cont’d.
17.2.5 TOC Instrum ent 5: Hig h tempe rature c ombustio n oxidation/N DIR

Dissolved O rganic Ca rbon, mg /L a

Source Water Unfortified Sample Conc. Fortified Sample Conc.
Mean %RSD Mean %REC Boulder Creek 1.21 1.18 11.0 98 Shingobe e R. 2.29 1.15 12.0 97 Bolten We ll 0.90 2.93 11.5 106 Ohio R. (Fernbank) 2.11 0.28 12.3 102 Muddy Creek 2.89 1.09 13.1 102 Great Mi ami R. 2.43 0.77 12.3 99 Saint L eon Well 0.38 27.4 10.0 96

Total Orga nic Carbon,

mg/L a

Source Water Unfortified Sample Conc. Fortified Sample Conc.
Mean %RSD Mean %REC Boulder Creek 1.26 6.02 11.0 97 Shingobe e R. 2.45 0.84 12.1 97 Bolten We ll 0.93 1.02 10.8 98 Ohio R. (Fernbank) 2.31 1.19 12.1 98 Muddy Creek 3.34 3.40 13.1 98 Great Mi ami R. 2.72 0.78 12.3 96 Saint L eon Well b 0.32 N/A 10.0 97

a N = 3, samples fortifie d at 10 mg/L OC using KHP b N = 2 fo

r this sa mple, N/A = not app licable415.3 - 48

17.3 PRECISIO N AND AC CURACY DATA FO R DOC ANDSUVA MEASU RED IN SEVEN SOURC E WATERS ON FIVE INSTRUM ENTS a
17.3.1 DOC Measurements for Seven Source Waters, Three Replicate Instrum ent Injec

tions on F ive Instr uments Dissolved Organic Carbon, mg/L, Unfortified Samples
Source Water Inst

#1 Inst #2 Inst #3 Inst #4 Inst #5 Mean Std

Dev %RSD
Boulder Creek 1.64 1.40 1.52 1.54 1.21 1.46 0.17 11 Shingobee R. 2.98 2.58 2.71 2.71 2.29 2.66 0.25 9 Bolton Well 1.27 1.04 1.18 1.24 0.90 1.13 0.15 14 Ohio R. ( Fernba nk) 2.79 2.41 2.50 2.52 2.12 2.47 0.24 10 Muddy Creek 3.81 3.25 3.38 3.56 2.89 3.38 0.34 10 Great Miami R. 3.18 2.69 2.91 3.00 2.43 2.84 0.29 10 St. Leo n Well 0.53 0.40 0.56 0.38 0.25 0.42 0.13 30
17.3.2 DOC Measurements for Seven Source Waters, F ortified with KHP, Three Replicate Instrument Injections on Five Instrum ents

Dissolv ed Orga nic Car

bon, mg /L, Sa mples For

tified at 10 mg/L

OC
Source Water Inst #1 Inst #2 Inst #3 Inst #4 Inst #5 Mean Std Dev %RSD %REC b
Boulder Creek 12.2 11.8 11.5 11.4 11.0 11.6 0.43 4 101 Shingobee R. 13.5 13.3 13.2 12.4 12.0 12.9 0.62 5 102 Bolton Well 12.0 11.5 11.3 11.2 11.5 11.5 0.31 3 104 Ohio R. ( Fernba nk) 13.6 13.2 13.1 12.4 12.3 12.9 0.54 4 105 Muddy Creek 14.6 14.3 14.0 13.3 13.1 13.9 0.62 5 105 Great Miami R. 13.7 13.4 13.1 12.7 12.3 13.0 0.55 4 102 St. Leo n Well 11.0 10.5 10.7 10.1 10.0 10.5 0.40 4 100

a For instrument id

entification (by ty

pe) see Section 6.3. b % Recovery c alculated as described in S ection 9.8.415.3 - 49

17.3 PRECISIO N AND AC CURACY DATA FO R DOC ANDSUVA MEASU RED IN SEVEN SOURC E WATERS ON FIVE INSTRUM ENTS a , cont’d.
17.3.3 Mean SUVA Calculation Based on the DOC Data in 17.3.1 for Seven Source Waters

Source Water UVA

(cm -1 ) SUVA b (L/mg-M)

Inst #1 Inst #2 Inst #3 Inst #4 Inst #5 Mean Boulder Creek 0.4324 2.62 3.08 2.84 2.97 3.58 3.02 Shingobee R. 0.7440 2.50 2.88 2.75 2.77 3.25 2.83 Bolton Well 0.2364 1.86 2.28 2.01 1.91 2.62 2.14 Ohio R. ( Fernba nk) 0.7267 2.60 3.01 2.90 2.88 3.43 2.97 Muddy Creek 1.124 2.95 3.46 3.33 3.20 3.89 3.37 Great Miami R. 0.8948 2.81 3.33 3.07 3.05 3.69 3.19 St. Leo n Well 0.0771 1.46 1.93 1.38 1.83 3.13 1.95

a For instrumen

t identification (by ty

pe) see Section 6.3. b SUVA calculated as des cribed in Section 12.2.415.3 - 50

17.4 PRECISIO N AND AC CURACY DATA FO R TOC MEASU RED IN SEVEN SOURCE WATE RS ON FIV E INSTRUMEN TS a
17.4.1 TOC Measur ement s for Seven S ource Wa ters, Thr ee Replic ate Instrument Injections on Five Instruments Total Organic Carbon , mg/L, Unfortified Samples
Source Water Inst #1 Inst #2 Inst #3 Inst #4 Inst #5 Mean Std Dev %RSD
Boulder Creek 1.73 1.38 1.47 1.46 1.26 1.46 0.17 12 Shingobee R. 3.16 2.62 2.72 2.84 2.45 2.76 0.26 10 Bolton Well 1.32 1.05 1.16 1.12 0.93 1.12 0.14 13 Ohio R. ( Fernba nk) 3.02 2.46 2.58 2.81 2.31 2.64 0.28 11 Muddy Creek 4.24 3.41 3.18 4.04 3.34 3.64 0.47 13 Great Miami R. 3.51 2.89 2.92 3.42 2.72 3.09 0.35 11 St. Leo n Well 0.66 0.39 0.45 0.28 0.32 0.42 0.15 35
17.4.2 TOC Measurements for Seven Source Waters, F ortified with KHP, from Replicat e Instrum ent Injec tions on F ive Instr uments

Total Or ganic C arbon,

mg/L, S amples Fo rtified at 10 mg/L OC
Source Water Inst #1 Inst #2 Inst #3 Inst #4 Inst #5 Mean Std Dev %RSD %REC b
Boulder Creek 12.1 11.3 11.2 11.4 11.0 11.4 0.43 4 99 Shingobee R. 13.0 12.7 12.6 12.5 12.1 12.6 0.32 3 98 Bolton Well 11.4 11.4 11.0 11.2 10.8 11.1 0.28 3 100 Ohio R. ( Fernba nk) 13.2 13.1 12.6 12.8 12.1 12.8 0.45 4 101 Muddy Creek 14.6 13.8 13.5 13.7 13.1 13.7 0.54 4 101 Great Miami R. 13.8 13.2 13.0 13.6 12.3 13.2 0.59 5 101 St. Leo n Well 11.1 10.5 10.7 10.2 10.0 10.5 0.41 4 101

a For instrument id

entification (by ty

pe) see Section 6.3. b % Recovery c alculated as described in S ection 9.8.415.3 - 51

17.5 INITIAL DEM ONSTRATION OF CAP ABILITY (ID C) REQUIR EMENTS (SUMMARY)

Method Reference Requirem ent Specificat ion and Frequency Accept ance Cri teria
Sects. 9.2.1, 9.9 Initial

Demonstration of Low Sy stem Background Analy ze LRB prior to any other I

DC samples. LRBs must be < 0.35 mg/L OC and < 0.01 cm -1 UVA.

Sects. 9.2.2, 9.11 Initial Calibration

Verification After initial calibration

of TOC instrument sys tem a QCS sa

mple is used to verify ac cu ra cy. The ana lyze d value of

a 1-5 mg /L calibration standard must be within ±20% of the true value before proceeding with the method. Sect. 9.2.3 Initi al Org anic

Carbon Flow Injection Memory Check Analyze after Low System Backg

round requirement, but before any

other TOC or DOC IDC samples. LRB i njection s after t

he high est OC-CAL injection must be <0.35 mg/L

TOC.

Sect. 9.2.4 Inorganic

Carbon Removal Prior to fi rst analy sis of samples and whe nev er t he IC removal procedu re is modified. Analysis of the IC-TEST solution after IC removal must result in a concentration of < 0.35 mg/L IC, measured as OC interference.

Sect. 9.2.5 Initial

Demonstration of Accuracy Analy ze 5 replic ate LFB s (at 2-5 mg/L OC). The average rec overy must be + 20% of the true value.

Sect. 9.2.6 Initial

Demonstration of Precision Calculate precision of

the acc uracy samples. The %RSD must be < 20%.

Sect. 9.2.7 Organic Carbon

Detecti on Lim

it (OC DL) Determination Analy ze 7 replic ate LFBs over a

period of at least 3 day s at a concentration estimated to be near th e DL. The calculated OCDL must not exceed 0.35 mg/L. The mea n recovery of the LFBs used in the OCDL determination must be + 50% of the true value.Method

Reference Requirem ent Specificat ion and Frequency Accept ance Cri teria

415.3 - 52 Sect. 9.3.2 Initial

Demonstration of Filter Membrane Suitability Prior to the first use of

filters and whenever a manufacturer or filter type is chang ed. FB < 0.35 mg/L OC and/or < 0.01 cm -1 UVA. Samp le filtrate OC within + 15% of unfilter ed sample OC. Sect. 9.4.1 Initial

Spectrophotometer Check Prior to fi rst instrument use and annually there after. Test two wavelengths between 220 and 340 nm. Check manufacturer’s operation manual for acc eptance

limits. Sects. 9.4.2, 10.4 Spectrophotometer

Performance Check Prior to analysis of

samples. UVA within 10% of expected absorbance value.415.3 - 53

17.6 QUALITY CONTROL REQUIREMENTS (SUMMARY)

Method Reference Requirem ent Specificat ion and Frequency Accept ance Cri teria

Sect. 9.9 Blanks One LRB with each T OC analysis batch. One FB with each DOC and UVA analysis batch. TOC LRBs and DOC-FBs must be < 0.35 mg/L OC. The UVA-FB must be < 0.01 cm -1 UVA. Sect. 8.1 Holding Time,

SUVA DOC - filtered and then

acidified within 48 hours of collection. Analyzed within 28 days of time of collection. Stored at < 6 °C; preserved with acid to pH < 2 after filtration.

UVA - filtered and analyzed within 48 hours of time of collection. Not preserved with acid, stored a t < 6 °C.

Sect. 8.2 Holding Time,

TOC TOC - analyze within 28

days from time of collection. Preserved at pH < 2 at the time of co llection, stored a t < 6 °C. Sects. 9.2, 9.3, 9.4 Initial

Demonstration of Capability (I

DC) Performed whenever a new instrument is set up or when a ne

w analy st is trained. See Table 17.5.

Sect. 9.5, 10.3 Continuing

Calibration Checks Analysis of Low-CCC (at

the MRL or below) at the beginn ing of e ach ana

lys is batch. Su bsequen t CCCs analyzed afte

r every 10 samples a nd after the last sample in t

he analy sis batch, rotating concentrations to cover the calibrated range of the instrumen t. Mid-CCC required during each analysis batch. Low- CCC: + 50% of true value. Mid-CCC: + 20% of true value. High-CC C: + 15% of true value.Method

Reference Requirem ent Specificat ion and Frequency Accept ance Cri teria

415.3 - 54 Sect. 9.6 Field Du

plicate (FD) An aly ses One FD is collected and

analy zed with ea

ch analy sis batch. FD > 2 mg/L OC < 20% RPD. UVA < 10% RPD.

Sect. 9.7 Laboratory

Fortified Blank (LF B) ana

lys is One L

FB is analy

zed with every D OC analysis batch. Concentr ation of 1 -5 mg/L OC using KHP. Recovery must be within + 20% of true value. Sect. 9.8 Laboratory

Fortifie d Matrix (LF M) One L FM is ana

lyze d with every T OC or DOC analysis batch. Spike concen tration should resu

lt in an increase in the LFM concen tration of 50 to 200% of its measured or expected concentration. Recovery outside 70-130% warrants investigation of matrix eff ect.

Sect. 9.11 Quality Control

Sample (Q CS) The QCS is analyzed

during the IDC, af

ter each new calibration curve, each time new calibration solutions are prepared, or at le as t q ua rt er ly. The analyzed va lue of a 1-5 mg/L QCS must be within ±20% of the true value.

Section 10.2 Calibration Curve A new ca libration curve is gener ated whe n fresh standards are made and/or when CCCs are out of QC limits. Calibration curve must have r 2 > 0.993 before proceeding with analyses.

Section 10.4 Spectrophotometer

performance check The day to day performance of the spe ctrophot

ometer is checke d using the COMMSCS and/or KHP-SCS prior to analyzing any

UVA sample(s). The UVA of the KHP-SCS or COMM-SCS reading must be within 10% expected absorba nce valu es. Anal ysi s of LRW must result in UVA of < 0.01 cm -1

.415.3 - 55 FIGURE 1: FILTER BLA NK PR EPARATI ON

LRW

WASH FIL TER*, DISCA RD

FILTER LRW*, DISPENSE INTO 40- ML VIA LS

DESIGNATE AS FILTER BLANK (FB)

DOC - FB ADD ACID SPARGE ANALYZE UVA - FB NO A CID NO SPARGE ANALYZE *Using volume as determined in Section 9.3.2.415.3 - 56 FIGURE 2 : SAMPLE PREPARA TION

WA TER SA MP LE

TOC DOC UVA

USIN G PRE - WASHED FILTERS FILTER AND DISCARD FI RST PORTION* TO WASTE

FILTE R R EMA INING SA MP LE

DISP ENS E INT O 40 ML VIA LS

TOC AND DOC -SA MP LE ADD ACID SPARGE ANALYZE UVA -SA MP LE NO A CID NO SPARGE ANALYZE * Using volume as determined in Section 9.3.2.3.