Major and Trace Element Analytical Methods of

the National Status and Trends Program:

2000-2006

NOAA Technical Memorandum NOS NCCOS 29
Mention of trade names or commercial products does not constitute 

endorsement or recommendation for their use by the United States 

government. 

Cover photograph: mussel bed at Throgs Neck, NY. 

Citation for this Report 

Kimbrough, K. L., and G. G. Lauenstein (Editors). 2006. Major and Trace Element 

Analytical Methods of the National Status and Trends Program: 2000-2006. Silver 

Spring, MD. NOAA Technical Memorandum NOS NCCOS 29, 19 pp. 
Major and Trace Element Analytical Methods of 

the National Status and Trends Program: Update 

2000 - 2006 

K. L. Kimbrough and G. G. Lauenstein 

(Editors) 

Center for Coastal Monitoring and Assessment 

NOAA/NOS/NCCOS 

1305 East-West Highway 

Silver Spring, Maryland 20910 

NOAA Technical Memorandum NOS NCCOS 29 

March 2007 

United States Department of 

Commerce 

National Oceanic and 

Atmospheric Administration 

National Ocean Service 

Carlos M. Gutierrez 

Secretary 

Conrad C. Lautenbacher, Jr. 

Administrator 

John H. Dunnigan 

Assistant Administrator 

TABLE OF CONTENTS

TABLE OF CONTENTS............................................................................................... i

LIST OF TABLES ........................................................................................................ ii

PREFACE ..................................................................................................................... 1

TRACE ELEMENT QUANTIFICATION TECHNIQUES: 2000 - 2006................... 2

ABSTRACT ............................................................................................................... 2

1.0 INTRODUCTION.......................................................................................... 2

2.0 EQUIPMENT AND SUPPLIES ..................................................................... 2

3.0 SAMPLE TREATMENT ............................................................................... 7

4.0 CALIBRATION AND ANALYSIS................................................................ 9

5.0 CALCULATIONS ......................................................................................... 9

6.0 INSTRUMENTAL ANALYSIS................................................................... 10

8.0 REFERENCES............................................................................................. 19

i 
LIST OF TABLES

Table 1. Baxter Ricca standards, 1000 ppm. Ricca Chemical Co., Arlington, TX. ........... 6

Table 2. Mussel Watch Project tissue major and trace elements, method limits of

detection (μg/g dry weight) for 2000 - 2003. ......................................................... 17

Table 3. Mussel Watch Project tissue major and trace elements, method limits of

detection (μg/g dry weight) for 2004. .................................................................... 18

ii 
PREFACE 

K. L. Kimbrough and G. G. Lauenstein

National Status and Trends Program

Center for Coastal Monitoring and Assessment

National Oceanic and Atmospheric Administration

Silver Spring, MD

This document contains analytical methods that detail the procedures for determining 

major and trace element concentrations in bivalve tissue and sediment samples collected 

as part of the National Status and Trends Program (NS&T) for the years 2000-2006. 

Previously published NOAA Technical Memoranda NOS ORCA 71 and 130 (Lauenstein 

and Cantillo, 1993; Lauenstein and Cantillo, 1998) detail trace element analyses for the 

years 1984-1992 and 1993-1996, respectively, and include ancillary, histopathology, and 

contaminant (organic and trace element) analytical methods. 

The methods presented in this document for trace element analysis were utilized by the 

NS&T Mussel Watch and Bioeffects Projects. The Mussel Watch Project has been 

monitoring contaminants in bivalves and sediment for over 20 years, and is the longest 

active contaminant monitoring program operating in U.S. costal waters. Approximately 

280 Mussel Watch sites are monitored on biennial and decadal timescales using bivalve 

tissue and sediment, respectively. The Bioeffects Project applies the sediment quality 

approach, which uses sediment contamination measurements, toxicity tests and benthic 

macroinfauna quantification to characterize pollution in selected estuaries and coastal 

embayments. Contaminant assessment is a core function of both projects. 

Although only one contract laboratory was used by the NS&T Program during the 

specified time period, several analytical methods and instruments were employed. The 

specific analytical method, including instrumentation and detection limit, is noted for 

each measurement taken and can be found at http://NSandT.noaa.gov. The major and 

trace elements measured by the NS&T Program include: Al, Si, Cr, Mn, Fe, Ni, Cu, Zn, 

As, Se, Sn, Sb, Ag, Cd, Hg, Tl and Pb. 

REFERENCES 

Lauenstein, G. G. and A. Y. Cantillo (eds.) (1998) Sampling and analytical methods of 

the National Status and Trends Program Mussel Watch Project 1993-1996 Update: TERL 

Trace Element Quantification Techniques, Volume III. NOAA Technical Memorandum 

NOS ORCA 71, Silver Spring, MD. 219 pp. 

Lauenstein, G. G. and A. Y. Cantillo (eds.) (1993) Sampling and analytical methods of 

the National Status and Trends Program National Benthic Surveillance and Mussel 

Watch Projects 1984-1992: Comprehensive descriptions of elemental analytical methods, 

Volume III. NOAA Technical Memorandum NOS ORCA 71, Silver Spring, MD. 219 pp. 

1 
TRACE ELEMENT QUANTIFICATION TECHNIQUES: 2000 - 2006

R. J. Taylor and B. L. Brattin

Department of Veterinary Integrative Biosciences

Texas A&M University

College Station, TX

ABSTRACT 

Sample preparation and analysis methods have been developed and refined that allow the 

accurate and precise determination of major and trace elements in sediment and 

biological tissue samples. Sample preparation emphasizes homogenization and total 

digestion steps that minimize contamination. Analyses utilize atomic spectroscopy 

techniques, including a full suite of quality assurance and quality control samples, with 

an emphasis on certified reference materials, in order to produce reliable data. These 

methods allow measurement of both background and elevated concentrations in samples 

collected as part of NOAA’s National Status and Trends Program. 

1.0 INTRODUCTION 

This method documents the analytical procedures used for major and minor element 

analysis of marine sediments and tissue samples collected by NOAA’s National Status 

and Trends Program. These procedures were used by the Trace Element Research 

Laboratory (TERL), Department of Veterinary Integrative Biosciences, Texas A&M 

University to analyze samples collected from 2000 to 2006. 

2.0 EQUIPMENT AND SUPPLIES 

2.1 INSTRUMENTATION 

Perkin-Elmer model DRC-2. Inductively coupled plasma mass spectrometry (ICP-MS) 

Perkin-Elmer, Norwalk, CT. Autosampler, Perkin-Elmer AS 93 Plus 

Spectro A.I. CIROS inductively coupled plasma optical emission spectrometry (ICPOES). Spectro A.I., Fitchburg, MA. Autosampler, Spectro A.I. model AS400 

Perkin-Elmer SIMAA 6000 graphite furnace atomic absorption spectrometry (GFAAS) 

Perkin-Elmer, Norwalk, CT. Autosampler, Perkin-Elmer model AS 72 

Perkin-Elmer Analyst 100 flame atomic absorption spectrometry (FAAS). Perkin-Elmer, 

Norwalk, CT 

PSA Millennium Excalibur atomic fluorescence spectrometer. PS Analytical, Orpington, 

Kent, UK. Autosampler, PS Analytical model AS300 

Cetac M7500 cold vapor atomic absorption Hg analyzer. Cetac Technologies, Omaha, 

NE. Autosampler, Cetac model ASX510 

2 
OI Analytical MDS 7295 microwave digestion system. OI Analytical, College Station, 

TX 

CPI ModBlock graphite block digestion system. CPI, Santa Rosa, CA 

2.2 SUPPLIES 

Argon, liquid 

Acetylene, welder’s grade 

Nitrogen, liquid 

Oxygen, compressed 

Nitrous oxide 

Hollow cathode lamps. Perkin-Elmer, Norwalk, CT 

Electrodeless discharge lamps (EDL). Perkin-Elmer, Norwalk, CT 

Boosted discharge hollow cathode lamps (BDHCL). Photron, Victoria, Australia 

Graphite tubes, THGA, Perkin-Elmer B0504033 

Autosampler cups, 1.1 mL, polystyrene, Perkin-Elmer N1012010 

Autosampler vials, 5 mL polypropylene, 60818-281. VWR Scientific Products, West 

Chester, PA 

2.3 LABWARE 

Balance, 0.01 g, Fisher 200 Ainsworth toploader. Fisher Scientific, Pittsburgh, PA 

Balance, 0.01 g, Mettler PC2000 

Balance, analytical, 0.0001 g, Mettler H10 

Balls, 1 cm diameter, Teflon 

Balls, 3.5 cm diameter, Teflon 

Bench, clean, with HEPA filter. Liberty Industries, East Berlin, CT 

Bottles, screw-cap bottles, polyethylene, wide-mouth, 1 oz., Nalgene 2104-0001 

Drying oven, 60 °C, NAPCO 332. Curtin-Matheson Scientific, Houston, TX 

Drying oven, 130 °C, Thelco 

3 
Freeze dryer system, Labconco Freezone 12L. Labconco, Kansas City, MO

Large jars, Teflon lined caps

Pipette tips, for Finnpette, Finntip 62. Labsystems

Pipette tips, polypropylene for Eppendorf pipettes, 10 - 100 mL Model 22 34190-1 and

200-1000 mL, 22 35 090-1

Pipette, Finnpette, adjustable, 1000 - 5000 mL 9402020. Curtin-Matheson Scientific,

Houston, TX

Pipette transfer, polyethylene

Pipettes, Eppendorf, fixed volume: 10 mL, 22350102; 25 mL, 22350307; 50 mL,

22350404; 100 mL, 22350501; 200 mL, 22350609; 500 mL, 22350706; 1000 mL,

22350803

Vials, snap-cap, polystyrene; 5, 15, and 40 dram. Baxter Scientific Products, McGaw

Park, IL

Vials, snap-cap, polyethylene, 70 mL. CPI, Santa Rosa, CA

2.4 REAGENTS 

Ammonium dihydrogen phosphate (NH4H2PO4) [7722-76-1], Spectropure Grade, P30. 

Spex, Edison, NJ 

Ascorbic acid (C6H8O6) [50-81-7], A-7506. Sigma, St. Louis, MO 

Boric acid (H3BO3) [10043-35-3], 10659, Grade 1. Johnson Matthey, West Chester, PA 

Citric acid (C6H8O7) [77-92-9], 0110. J. T. Baker, Phillipsburg, NJ 

Hydrochloric acid (HCl) [7647-01-0], concentrated (37%), Ultrex 6900-05. J. T. Baker, 

Phillipsburg, NJ 

Hydrofluoric acid (HF) [7664-39-3], concentrated (48%), 9560-06. J. T. Baker, 

Phillipsburg, NJ 

Magnesium nitrate [Mg(NO3)2 .6H20] [13446-18-9], MG60-50. Spex, Edison, NJ 

Nickel oxide (Ni0) [1313-99-1], powder. Spex, Edison, NJ 

Nitric acid (HNO3) [7697-37-2], concentrated (70%), 2704-7x6. Mallinckrodt, Paris, KY 

Nitric acid (HNO3) [7697-37-2], concentrated (70%), Ultrex 6901-05. J. T. Baker, 

Phillipsburg, NJ 

4 
Palladium metal [7440-05-3], Specpure, 560001. Johnson Matthey, West Chester, PA 

Stannous chloride, (SnCl2 . 2H2O) [10025-69-1], 8176. Mallinckrodt, Paris, KY 

Water, redistilled in quartz sub-boiling still 

2.5. MATRIX MODIFIERS 

Ammonium phosphate: 0.04 g/mL in quartz-distilled water 

Ascorbic acid: 2% w/v made with quartz-distilled water 

Citric acid: 2% w/v made with quartz-distilled water 

Hydroxylamine hydrochloride 

Magnesium nitrate: 0.02 g/mL in quartz-distilled water 

Palladium nitrate: 1000 mg Pd/mL made by dissolving 0.05 g Pd metal in 2 mL 

Concentrated Ultrex HNO3 and diluted to 50 mL with quartz-distilled water 

5 
2.6. STANDARDS 

2.6.1. INORGANIC VENTURES, LAKEWOOD, NJ 

Table 1. Baxter Ricca standards, 1000 ppm. Ricca Chemical Co., Arlington, TX 

Individual elements standards, 1,000 

Element Stock number 

Hg CGHG1-1 

Individual element standards, 10,000 ppm. 

Element Stock number 

Ag CGAG10-1 

Al CGAL10-1 

As CGAS10-1 

Cd CGCD10-1 

Cr CGCR10-1 

Cu CGCU10-1 

Fe CGFE10-1 

Mn CGMN10-1 

Ni CGNI10-1 

Pb CGPB10-1 

Sb CGSB10-1 

Se CGSE10-1 

Sn CGSN10-1 

Tl CGTL10-1 

Zn CGZN10-1 

QC-1 mixed standard, 100 ppm: Al, Fe, Zn; 10 ppm: Ba, Be, B, Cd, Ag, Sr 

QC-2 mixed standard, 100 ppm: Sb, As, Cr, Co, Cu, Pb, Mn, Mo, Ni, Se, Tl, Sn, Ti, V 

ICP-MS custom mixed standard, 10 ppm: Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, 

Mn, Mo, Ni, Pb, Sb, Se, Sn, Sr, Th, Tl, U, V, Zn 

6 
2.6.2 CPI, SANTA ROSA, CA 

ICP-MS internal standard, 10 ppm: 

Li-6, Rh, Bi, Ho, Sc, Tb, In 

3.0 SAMPLE TREATMENT 

3.1 OYSTER AND MUSSEL TISSUE 

3.1.1 BIVALVE SHUCKING 

Whole oysters and mussels were rinsed with distilled water to remove extraneous 

material and shucked with a stainless steel knife (using care not to touch the tissue). 

Whole soft tissue was removed with plastic forceps and rinsed with distilled, deionized 

water to remove sediment particles from gills and exterior tissue surfaces. Soft parts were 

transferred to a tared Ziploc polyethylene bag, and the number of individuals shucked and 

placed in the bag was recorded. When soft tissue from all individuals from a site had 

been collected, they were weighed on a top loading balance to measure the total sample 

wet weight. The pooled samples were stored in a freezer. 

3.1.2 BULK HOMOGENIZING 

Ziploc bags containing pooled tissue were removed from the freezer and allowed to thaw. 

The entire pooled sample was transferred to an acid-washed Teflon jar and 3 large Teflon 

balls were added. The Teflon lids were securely tightened and the jars placed in Ziploc 

bags and shaken in an industrial paint shaker for 20 min. After the bulk sample was 

homogenized, an aliquot of the sample was transferred to a clean 40 dram snap vial and 

frozen. 

3.1.3 FREEZE DRYING 

The frozen aliquot from the bulk homogenization step was placed in a freeze drier and 

allowed to dry for several days, depending upon the total mass of tissue being dried at 

one time. In some cases it was necessary to remove the samples from the freeze drier and 

drain accumulated water from the trap before continuing with the drying step. 

3.1.4 HOMOGENIZATION OF DRY ALIQUOT 

When samples were thoroughly dried, three small Teflon balls were inserted into each 

snap cap vial, the lids were affixed, and the samples placed in a Spex shaker mill for 1 

min. The Teflon balls were then removed, and the samples stored in closed vials until 

weighing. 

3.1.5 DIGESTION 

Approximately 0.2 g samples of dried tissue were weighed to the nearest 0.0001 g and 

transferred to tared, acid-washed Teflon bombs. A 3 mL aliquot of HNO3 was added and 

7 
the bombs sealed in a digestion system and cooked according to the appropriate method 

(Section 3.2.4). The samples were allowed to cool and 1 mL of H2O2 was added to each 

sample, then heated to promote the reaction. After the samples were allowed to cool, 1 

mL of HCl was added to each sample, and then heated gently. The samples were cooled 

and 15 mL of deionized distilled water was added. The bombs were closed, mixed by 

shaking, and weighed to 0.01 g to determine the total solution weight. The digest solution 

was transferred to labeled 1 oz polyethylene bottles. Solution density was determined by 

weighing known volumes with calibrated Eppendorf pipettes in order to determine 

solution volume. 

For analysis of Hg, tissue samples were digested using a modified version of the 

Environmental Protection Agency (EPA) method 245.6. Approximately 0.15 to 0.3 g (dry 

weight) of sample was weighed into a 70 mL snap cap vial. Concentrated H2SO4 (2.5 mL) 

and 1.5 mL of concentrated HNO3 were added and the samples heated in a digestion 

block at 90 - 95 °C for 30 min. After cooling, 10 mL of distilled water, 10 mL of 5% 

(w/w) KMnO4, and 5 mL of 5% (w/w) of K2S2O8 were added to each tube, and the 

samples left overnight without heating. Before analysis, 5 mL of 10% (w/w) NH2OH . 

HCl were added to reduce excess KMnO4 and the volume brought to 40 mL with distilled 

water. 

3.2 BOTTOM SEDIMENT 

Bottom sediment samples were prepared for analysis by freeze drying and wet digestion. 

3.2.1 HOMOGENIZATION 

Wet bulk sediment was stored frozen until sample processing began. Sediment was 

thawed and homogenized with a clean plastic spatula. A homogeneous aliquot of the bulk 

sample was transferred to a labeled 40 dram snap cap vial and frozen. The remainder of 

the sample was archived in the freezer. 

3.2.2 FREEZE DRYING 

The snap cap vial containing the sediment sub-sample was placed in a freeze drier for the 

period of time required for complete drying. Depending upon the amount of water in the 

freeze drier, this ranged from 12 - 76 hr. 

3.2.3 HOMOGENIZATION OF DRY ALIQUOT 

In some cases, homogenization of freeze dried sediment was accomplished by simply 

placing the snap cap vials in a Spex shaker. When this was not sufficient, the samples 

were individually ground in alumina mortar and pestles and the powdered samples 

returned to the vials in which they were freeze dried. 

8 
3.2.4 DIGESTION 

Approximately 0.2 g of homogenized, dried sediment was weighed to the nearest 

0.0001 g and transferred to tared 70 mL snap cap vials. A 3 mL aliquot of HNO3 was 

added and the vials were placed in a 95 °C digestion block for a total of approximately 6 

hr. During this time, the vials were periodically removed from the block and swirled to 

mix. After this period, the vials were removed from the block and allowed to cool before 

2 mL of concentrated HF was added. The vials were then returned to the block for 

approximately 2 hr. After cooling, 15 mL of 4% boric acid were added and the vials 

returned to the block for another 1 to 2 hr. After the samples were allowed to cool, the 

content of the vials were mixed by shaking, and the vials weighed to 0.01 g to determine 

the total solution weight. Digest solutions were then transferred to labeled 1 oz 

polyethylene bottles. Solution density was determined by weighing known volumes with 

calibrated Eppendorf pipettes in order to determine solution volume. 

For analysis of Hg, sediment samples were digested using a modified version of EPA 

method 245.5. Approximately 0.1 to 1.0 g (dry weight) of sample was weighed into a 70 

mL snap cap vial. Concentrated H2SO4 (2.5 mL) and 1.5 mL of concentrated HNO3 were 

added and the samples heated in a digestion block at 90 - 95 °C for 30 min. After cooling, 

10 mL of distilled water, 10 mL of 5% (w/w) KMnO4, and 5 mL of 5% (w/w) of K2S2O8 

were added to each tube, and the samples again heated in a digestion block at 90 - 95 °C 

for 30 min. Before analysis, 5 mL of 10% (w/w) NH2OH . HCl were added to reduce 

excess KMnO4 and the volume brought to 40 mL with distilled water. 

4.0 CALIBRATION AND ANALYSIS 

Calibration standards were prepared by serial dilution of commercially available 

standards using calibrated micropipettes, a top loading balance, deionized distilled water 

and acids to match the matrix of the samples and methods. Concentrations of working 

standards were verified by comparison with independent standards traceable to the 

National Institute of Standards and Technology (NIST) Standard Reference Materials. 

In all cases, final working standards were prepared in an acid matrix that matched that of 

the samples being analyzed. For some elements, it was necessary to further attempt to 

match the major ion composition of the samples. This was most apparent in graphite 

furnace AAS when the peak shape of the samples was significantly different from that of 

the standards. For example, the standards may have a relatively broad, Gaussian-shaped 

peak while the sediment samples may have an extremely sharp peak, indicative of rapid 

volatilization of the metal. In this case, the standards were prepared in a solution that had 

Si, Al, Fe, Ca, and Mg added at final concentrations of 3000, 400, 200, 100, and 100 ppb, 

respectively. 

5.0 CALCULATIONS 

Trace metal concentrations were calculated by comparing analytical signals of unknowns 

with those of calibration standards, and then multiplying the observed concentration by 

the instrumental and digestion dilution factors. 

9 
The least-squares fit of the data was calculated, treating Abs (or Abs-sec., emission 

intensity, mass/charge ratio, etc.) as the dependent variable (y), and concentration as the 

independent variable (x). If the concentration range extended into the non-linear range, a 

second order fit was used. The intercept, the first and second order coefficients (if 

appropriate), and R, the correlation coefficient, were calculated. 

Abs = a + b (concobs) 

Abs - a 

concobs = b 

where concobs was the calculated observed concentration, Abs was the instrumental signal 

(e.g., Absorbance for atomic absorption instruments, emission for ICP-OES, or counts 

per second for ICP-MS), a was the intercept, and b was the slope of the regression line. 

5.1 DILUTION FACTOR 

The dilution factor, DF, resulting from sample digestion was calculated using the 

equation 

[(bomb tot.) - (bomb tare)] DF = (spl. wt.) x (soln. dens.) 

where bomb tare was the tare weight of the digestion vessel (g); bomb tot. was the total 

weight of the digestion vessel plus digest solution (g); spl. wt. was the weight of the dry 

sample (g); and soln. dens. was the density of the digest solution (g/cm3). 

5.2 CONCENTRATION 

The concentration in the original sample was calculated according to the relationship: 

If concobs < DL, final concentration ≤ (DL) (DFinstr) (DFdign) 

If concobs ≥ DL, final concentration = (concobs) (DFinstr) (DFdign) 

where concobs was the concentration observed in the aqueous sample; DL was the 

detection limit of the analytical technique; DFinstr was the dilution factor of the analytical 

technique, if necessary; and DFdign was the dilution factor of the sample digestion. 

6.0 INSTRUMENTAL ANALYSIS 

6.1 INDUCTIVELY COUPLED PLASMA - MASS SPECTROMETRY 

Silver, aluminum, chromium, cadmium, nickel, lead, antimony, and tin in sediments or 

tissues 

METHOD: 

10 
Inductively coupled plasma - mass spectrometry 

DIGEST MATRIX: 

1 to 10 dilution of digestate with reagent water 

INSTRUMENT SETTINGS: 

Instrument settings change on a daily basis as sensitivity is optimized. This is especially 

true for autolens settings and dual detector calibration. The following software settings 

give typical values for parameters that remain relatively constant in day-to-day operation: 

Power: 1400 watts 

Plasma gas flow: 15 L/min. 

Auxiliary flow: 1.2 L/min. 

Nebulizer flow: 1.0 L/min. 

Analog stage voltage: -2200 V 

Pulse stage voltage: 1200 V 

Quadrupole rod offset: -3 V 

Cell rod offset: -9 V 

RPQ: 0.25 

Cell path voltage: -24 V 

Sample uptake: 1 mL/min. 

Internal standard uptake: 0.1 mL/min. 

PROCEDURE: 

Scan mode: peak hopping 

Dwell time per AMU: 50 msec. 

Sweeps/reading: 20 

Integration time: 1000 msec. 

Replicates: 3 

Autolens: On 

11 
Blank subtraction: After internal standard 

Measurement unit: cps 

Mode: Dual (pulse/analog) 

Internal standards: Ga, Rh, In, Bi 

STANDARDS: 

Calibration standards (representative of sample concentration) are prepared from 

dilutions of NIST-traceable multi-element standards. The low concentration standard is 

based on instrument sensitivity (e.g., 0.05 ppb for Pb, 0.5 ppb for Al). Mid and high 

standards are at 20 and 200 ppb, respectively. Other reference materials (NIST 1640 

Trace Elements in Water) are used as check standards. Calibration verification is 

performed periodically with a blank and mid-range standard (20 ppb). 

TYPICAL SENSITIVITY: 

Sensitivity is approximately 5 x 107 counts per sec. per ppm for In - 115.

CALIBRATION:

Weighted linear, least-squares regression.

7.2 INDUCTIVELY COUPLED PLASMA - OPTICAL EMISSION 

SPECTROMETRY 

Aluminum, arsenic, chromium, copper, iron, manganese, nickel, silver, and zinc in 

sediments or tissues.

METHOD:

Inductively coupled plasma - optical emission spectrometry

DIGEST MATRIX:

Direct analysis of digestate

INSTRUMENT SETTINGS:

The following software settings give typical values for parameters that remain relatively

constant in day-to-day operation:

Power: 1400 watts

Plasma gas flow: 12 L/min.

Auxiliary flow: 1.0 L/min.

12 
Nebulizer flow: 0.7 L/min.

PROCEDURE:

Integration time: 45 sec.

Integration option: “Best SNR”

Internal standards: Au, In, Yb

STANDARDS:

Calibration standards are prepared from dilutions of NIST-traceable single element

standards. Calibration verification standards are prepared from dilutions of NISTtraceable multi-element standards. All standards are prepared to match sample matrix.

CALIBRATION:

Weighted linear, least-squares regression.

13 
7.3 ATOMIC FLUORESCENCE SPECTROMETRY 

Arsenic and selenium in sediments or tissues 

METHOD: 

Hydride generation - atomic fluorescence spectrometry 

DIGEST MATRIX: 

1 to 10 dilution of digestate, final 3N HCl matrix 

INSTRUMENT SETTINGS: The following software settings give typical values for 

parameters that remain relatively constant in day-to-day operation: 

ANALYTE: As Se 

Primary lamp current: 27.5 mA 20 mA 

Boost lamp current: 35 mA 25 mA 

Gain: 100 10 

Pump 1 speed: 100 100 

Pump 2 speed: 50 50 

Range (ppb): 0 – 50 0 - 10 

Mode: Pk height Pk area 

Typical sensitivity (1 ppb): 20 500 

PROCEDURE:

Delay time: 30 sec.

Analysis time: 20 sec.

Memory time: 50 sec.

STANDARDS:

Calibration standards are prepared from dilutions of NIST-traceable single element

standards. Calibration verification standards are prepared from dilutions of NISTtraceable multi-element standards. All standards are prepared to match sample matrix. 

CALIBRATION: Weighted linear, least-squares regression. 

14 
7.4 ATOMIC ABSORPTION SPECTROMETRY 

Hg in sediments or tissues

METHOD:

Cold vapor - atomic absorption spectrometry

DIGEST MATRIX:

Direct analysis of digestate

INSTRUMENT SETTINGS:

The following software settings give typical values for parameters that remain relatively

constant in day-to-day operation:

Argon flow rate: 150 mL/min.

Pump rate: 50%

Range: 0 – 50 ppb

PROCEDURE:

Sampling time: 23 sec.

Delay time: 53 sec.

Read time: 5 sec.

Replicates: 5

Background read time: 10 – 14 sec.

Rinse time: 70 sec.

STANDARDS:

Calibration standards are prepared from dilutions of NIST-traceable single element

standard. Calibration verification standards are prepared from dilutions of a different

NIST-traceable single element standard. All standards are prepared in 7% v/v HCl

matrix. 

CALIBRATION: 

Weighted linear, least-squares regression. 

15 
7.5 MICROWAVE DIGESTION PROGRAM 

Trace metals, including Hg in sediments or tissues

INSTRUMENT SETTINGS:

The following software settings give typical values for parameters that remain relatively

constant in day-to-day operation:

PROCEDURE:

Pressurized steps (nitric acid, hydrofluoric acid):

POWER SETTING DWELL MAX 

STAGE (%) (psi) (min.) (min.) 

1 50 20 2 5

2 75 40 5 6

3 75 60 2 3

4 75 80 2 3

5 75 100 2 3

6 75 120 2 3

7 75 140 15 16

Non-pressurized steps (hydrogen peroxide, hydrochloric acid, boric acid): 

POWER (%) SETTING (°C) DWELL (min.) MAX (min.)

25 85 5 10

16 
7.6 DETECTION LIMITS 

The analytical detection limits were determined by following procedures outlined in the 

Federal Register (1984). Method detection limits for specific measurements can be found 

online at http://NSandT.noaa.gov. 

Table 2. Mussel Watch Project tissue major and trace elements, method limits of 

detection (μg/g dry weight) for 2000 – 2003*. 

Sample size 

Element (method) 

Tissue MDL 

200 mg 

n=9 

Sediment MDL 

300 mg 

n=2 

Ag (ICP-MS) 

Al (ICP) 

As (ICP) 

Cd (ICP) 

Cr (ICP) 

Cu (ICP) 

Fe (ICP) 

Hg (CVAAS) 

Mn (ICP) 

Ni (ICP) 

Pb (ICP-MS) 

Sb (ICP-MS) 

Se (AFS) 

Si (ICP) 

Sn (ICP-MS) 

Zn (ICP) 

0.05 

6.32 

2.53 

0.25 

0.63 

0.63 

1.27 

0.03 

0.25 

0.63 

0.06 

N/A 

0.03 

N/A 

0.13 

1.18 

0.06 

24.6 

1.97 

0.07 

0.20 

0.20 

9.83 

0.02 

0.10 

0.49 

0.07 

0.10 

0.03 

246 

0.20 

0.20 

Note: Tissue MDLs were calculated by averaging the concentration for each analyte for all blanks analyzed 

with the 2003 samples (not including Great Lakes samples which were analyzed with 2004 samples). 

Sediment MDLs were calculated by averaging the concentration for each analyte for all blanks analyzed 

with the 2003 sediments. 

* All samples from 2000-2003 were analyzed in 2003. 

17 
Table 3. Mussel Watch Project tissue major and trace elements, method limits of 

detection (μg/g dry weight) for 2004. 

Sample Size 

Tissue MDL 

200 mg 

n=9 

Sediment MDL 

300 mg 

n=2 

Ag (ICP-MS) 0.04 0.06 

Al (ICP) 4.88 24.6 

As (ICP) 1.95 1.97 

Cd (ICP) 0.20 0.07 

Cr (ICP) 0.49 0.20 

Cu (ICP) 0.49 0.20 

Fe (ICP) 1.10 9.83 

Hg (CVAAS) 0.01 0.02 

Mn (ICP) 0.20 0.10 

Ni (ICP) 0.49 0.49 

Pb (ICP-MS) 0.043 0.07 

Sb (ICP-MS) N/A 0.10 

Se (AFS) 0.05 0.03 

Si (ICP) N/A 246 

Sn (ICP-MS) 0.09 0.20 

Zn (ICP) 0.50 0.20 

18 
8.0 REFERENCES 

Federal Register. 1984. vol. 49, No. 209:198-199. 

19
United States Department of Commerce 

Carlos M. Gutierrez 

Secretary 

National Oceanic and Atmospheric Administration 

Vice Admiral Conrad C. Lautenbacher, Jr. USN (Ret.) 

Under Secretary of Commerce for Oceans and Atmospheres 

National Ocean Service 

John H. Dunnigan 

Assistant Administrator for Ocean Service and Coastal Zone Management