www.epa.gov 1994 

Method 200.8, Revision 5.4: 

Determination of Trace Elements 

in Waters and Wastes by 

Inductively Coupled Plasma – 

Mass Spectrometry 
METHOD 200.8
 

DETERMINATION OF TRACE ELEMENTS IN WATERS AND WASTES
 

BY INDUCTIVELY COUPLED PLASMA - MASS SPECTROMETRY
 

Revision 5.4
 

EMMC Version
 

S.E. Long (Technology Applications Inc.), T.D. Martin, and E.R. Martin - Method 200.8, 

Revisions 4.2 and 4.3 (1990) 

S.E. Long (Technology Applications Inc.) and T.D. Martin - Method 200.8, Revision 4.4 (1991) 

J.T. Creed, C.A. Brockhoff, and T.D. Martin - Method 200.8, Revision 5.4 (1994) 

ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
 

OFFICE OF RESEARCH AND DEVELOPMENT
 

U.S. ENVIRONMENTAL PROTECTION AGENCY
 

CINCINNATI, OHIO 45268
 

METHOD 200.8
 

200.8-1
 
DETERMINATION OF TRACE ELEMENTS IN WATERS AND WASTES
 

BY INDUCTIVELY COUPLED PLASMA - MASS SPECTROMETRY
 

1.0	 SCOPE AND APPLICATION 

1.1	 This method provides procedures for determination of dissolved elements in 

ground waters, surface waters and drinking water. It may also be used for 

determination of total recoverable element concentrations in these waters as well 

as wastewaters, sludges and soils samples. This method is applicable to the 

following elements: 

Chemical Abstract Services 

Analyte Registry Number (CASRN) 

Aluminum (Al) 7429-90-5 

Antimony (Sb) 7440-36-0 

Arsenic (As) 7440-38-2 

Barium (Ba) 7440-39-3 

Beryllium (Be) 7440-41-7 

Cadmium (Cd) 7440-43-9 

Chromium (Cr) 7440-47-3 

Cobalt (Co) 7440-48-4 

Copper (Cu) 7440-50-8 

Lead (Pb) 7439-92-1 

Manganese (Mn) 7439-96-5 

Mercury (Hg) 7439-97-6 

Molybdenum (Mo) 7439-98-7 

Nickel (Ni) 7440-02-0 

Selenium (Se) 7782-49-2 

Silver (Ag) 7440-22-4 

Thallium (Tl) 7440-28-0 

Thorium (Th) 7440-29-1 

Uranium (U) 7440-61-1 

Vanadium (V) 7440-62-2 

Zinc (Zn) 7440-66-6 

Estimated instrument detection limits (IDLs) for these elements are listed in 

Table 1. These are intended as a guide to instrumental limits typical of a system 

optimized for multielement determinations and employing commercial 

instrumentation and pneumatic nebulization sample introduction. However, 

actual method detection limits (MDLs) and linear working ranges will be 

dependent on the sample matrix, instrumentation and selected operating 

conditions. Given in Table 7 are typical MDLs for both total recoverable 

determinations by "direct analysis" and where sample digestion is employed. 

200.8-2
 
1.2	 For reference where this method is approved for use in compliance monitoring 

programs [e.g., Clean Water Act (NPDES) or Safe Drinking Water Act (SDWA)] 

consult both the appropriate sections of the Code of Federal Regulation (40 CFR 

Part 136 Table 1B for NPDES, and Part 141 § 141.23 for drinking water), and the 

latest Federal Register announcements. 

1.3	 Dissolved elements are determined after suitable filtration and acid preservation. 

In order to reduce potential interferences, dissolved solids should not exceed 

0.2% (w/v) (Section 4.1.4). 

1.4	 With the exception of silver, where this method is approved for the determination 

of certain metal and metalloid contaminants in drinking water, samples may be 

analyzed directly by pneumatic nebulization without acid digestion if the samples 

have been properly preserved with acid and have turbidity of <1 NTU at the time 

of analysis. This total recoverable determination procedure is referred to as 

"direct analysis". 

1.5	 For the determination of total recoverable analytes in aqueous and solid samples 

a digestion/extraction is required prior to analysis when the elements are not in 

solution (e.g., soils, sludges, sediments and aqueous samples that may contain 

particulate and suspended solids). Aqueous samples containing suspended or 

particulate material ≥1% (w/v) should be extracted as a solid type sample 

(Section 11.2.2). 

1.6	 The total recoverable sample digestion procedure given in this method is not 

suitable for the determination of volatile organo-mercury compounds. However, 

for "direct analysis" of drinking water (turbidity <1 NTU), the combined 

concentrations of inorganic and organo-mercury in solution can be determined by 

"direct analysis" pneumatic nebulization provided gold is added to both samples 

and standards alike to eliminate memory interference effects. 

1.7	 Silver is only slightly soluble in the presence of chloride unless there is a 

sufficient chloride concentration to form the soluble chloride complex. Therefore, 

low recoveries of silver may occur in samples, fortified sample matrices and even 

fortified blanks if determined as a dissolved analyte or by "direct analysis" where 

the sample has not been processed using the total recoverable mixed acid 

digestion. For this reason it is recommended that samples be digested prior to 

the determination of silver. The total recoverable sample digestion procedure 

given in this method is suitable for the determination of silver in aqueous samples 

containing concentrations up to 0.1 mg/L. For the analysis of wastewater 

samples containing higher concentrations of silver, succeeding smaller volume, 

well mixed sample aliquots must be prepared until the analysis solution contains 

<0.1 mg/L silver. The extraction of solid samples containing concentrations of 

silver >50 mg/kg should be treated in a similar manner. 

1.8	 The total recoverable sample digestion procedure given in this method will 

solubilize and hold in solution only minimal concentrations of barium in the 

presence of free sulfate. For the analysis of barium in samples having varying 

200.8-3
 
and unknown concentrations of sulfate, analysis should be completed as soon as 

possible after sample preparation. 

1.9	 This method should be used by analysts experienced in the use of inductively 

coupled plasma mass spectrometry (ICP-MS), the interpretation of spectral and 

matrix interferences and procedures for their correction. A minimum of six 

months experience with commercial instrumentation is recommended. 

1.10	 Users of the method data should state the data-quality objectives prior to analysis. 

Users of the method must document and have on file the required initial 

demonstration performance data described in Section 9.2 prior to using the 

method for analysis. 

2.0	 SUMMARY OF METHOD 

2.1	 An aliquot of a well mixed, homogeneous aqueous or solid sample is accurately 

weighed or measured for sample processing. For total recoverable analysis of a 

solid or an aqueous sample containing undissolved material, analytes are first 

solubilized by gentle refluxing with nitric and hydrochloric acids. After cooling, 

the sample is made up to volume, is mixed and centrifuged or allowed to settle 

overnight prior to analysis. For the determination of dissolved analytes in a 

filtered aqueous sample aliquot, or for the "direct analysis" total recoverable 

determination of analytes in drinking water where sample turbidity is <1 NTU, 

the sample is made ready for analysis by the appropriate addition of nitric acid, 

and then diluted to a predetermined volume and mixed before analysis. 

2.2	 The method describes the multi-element determination of trace elements by ICPMS.1-3 Sample material in solution is introduced by pneumatic nebulization into 

a radiofrequency plasma where energy transfer processes cause desolvation, 

atomization and ionization. The ions are extracted from the plasma through a 

differentially pumped vacuum interface and separated on the basis of their massto-charge ratio by a quadrupole mass spectrometer having a minimum resolution 

capability of 1 amu peak width at 5% peak height. The ions transmitted through 

the quadrupole are detected by an electron multiplier or Faraday detector and the 

ion information processed by a data handling system. Interferences relating to 

the technique (Section 4.0) must be recognized and corrected for. Such corrections 

must include compensation for isobaric elemental interferences and interferences 

from polyatomic ions derived from the plasma gas, reagents or sample matrix. 

Instrumental drift as well as suppressions or enhancements of instrument 

response caused by the sample matrix must be corrected for by the use of internal 

standards. 

3.0	 DEFINITIONS 

3.1	 Calibration Blank - A volume of reagent water acidified with the same acid 

matrix as in the calibration standards. The calibration blank is a zero standard 

and is used to calibrate the ICP instrument (Section 7.6.1). 

200.8-4
 
3.2	 Calibration Standard (CAL) - A solution prepared from the dilution of stock 

standard solutions. The CAL solutions are used to calibrate the instrument 

response with respect to analyte concentration (Section 7.4). 

3.3	 Dissolved Analyte - The concentration of analyte in an aqueous sample that will 

pass through a 0.45 μm membrane filter assembly prior to sample acidification 

(Section 11.1). 

3.4	 Field Reagent Blank (FRB) - An aliquot of reagent water or other blank matrix 

that is placed in a sample container in the laboratory and treated as a sample in 

all respects, including shipment to the sampling site, exposure to the sampling 

site conditions, storage, preservation, and all analytical procedures. The purpose 

of the FRB is to determine if method analytes or other interferences are present 

in the field environment (Section 8.5). 

3.5	 Instrument Detection Limit (IDL) - The concentration equivalent to the analyte 

signal which is equal to three times the standard deviation of a series of 10 

replicate measurements of the calibration blank signal at the selected analytical 

mass(es). (Table 1). 

3.6	 Internal Standard - Pure analyte(s) added to a sample, extract, or standard 

solution in known amount(s) and used to measure the relative responses of other 

method analytes that are components of the same sample or solution. The 

internal standard must be an analyte that is not a sample component (Sections 7.5 

and 9.4.5). 

3.7	 Laboratory Duplicates (LD1 and LD2) - Two aliquots of the same sample taken 

in the laboratory and analyzed separately with identical procedures. Analyses of 

LD1 and LD2 indicates precision associated with laboratory procedures, but not 

with sample collection, preservation, or storage procedures. 

3.8	 Laboratory Fortified Blank (LFB) - An aliquot of LRB to which known quantities 

of the method analytes are added in the laboratory. The LFB is analyzed exactly 

like a sample, and its purpose is to determine whether the methodology is in 

control and whether the laboratory is capable of making accurate and precise 

measurements (Sections 7.9 and 9.3.2). 

3.9	 Laboratory Fortified Sample Matrix (LFM) - An aliquot of an environmental 

sample to which known quantities of the method analytes are added in the 

laboratory. The LFM is analyzed exactly like a sample, and its purpose is to 

determine whether the sample matrix contributes bias to the analytical results. 

The background concentrations of the analytes in the sample matrix must be 

determined in a separate aliquot and the measured values in the LFM corrected 

for background concentrations (Section 9.4). 

3.10	 Laboratory Reagent Blank (LRB) - An aliquot of reagent water or other blank 

matrices that are treated exactly as a sample including exposure to all glassware, 

equipment, solvents, reagents, and internal standards that are used with other 

samples. The LRB is used to determine if method analytes or other interferences 

200.8-5
 
are present in the laboratory environment, reagents, or apparatus (Sections 7.6.2 

and 9.3.1). 

3.11	 Linear Dynamic Range (LDR) - The concentration range over which the 

instrument response to an analyte is linear (Section 9.2.2). 

3.12	 Method Detection Limit (MDL) - The minimum concentration of an analyte that 

can be identified, measured, and reported with 99% confidence that the analyte 

concentration is greater than zero (Section 9.2.4 and Table 7). 

3.13	 Quality Control Sample (QCS) - A solution of method analytes of known 

concentrations which is used to fortify an aliquot of LRB or sample matrix. The 

QCS is obtained from a source external to the laboratory and different from the 

source of calibration standards. It is used to check either laboratory or instrument 

performance (Sections 7.8 and 9.2.3). 

3.14	 Solid Sample - For the purpose of this method, a sample taken from material 

classified as either soil, sediment or sludge. 

3.15	 Stock Standard Solution - A concentrated solution containing one or more 

method analytes prepared in the laboratory using assayed reference materials or 

purchased from a reputable commercial source (Section 7.3). 

3.16	 Total Recoverable Analyte - The concentration of analyte determined either by 

"direct analysis" of an unfiltered acid preserved drinking water sample with 

turbidity of <1 NTU (Section 11.2.1), or by analysis of the solution extract of a 

solid sample or an unfiltered aqueous sample following digestion by refluxing 

with hot dilute mineral acid(s) as specified in the method (Sections 11.2 and 11.3). 

3.17	 Tuning Solution - A solution which is used to determine acceptable instrument 

performance prior to calibration and sample analyses (Section 7.7). 

3.18	 Water Sample - For the purpose of this method, a sample taken from one of the 

following sources: drinking, surface, ground, storm runoff, industrial or domestic 

wastewater. 

4.0	 INTERFERENCES 

4.1	 Several interference sources may cause inaccuracies in the determination of trace 

elements by ICP-MS. These are: 

4.1.1	 Isobaric elemental interferences - Are caused by isotopes of different 

elements which form singly or doubly charged ions of the same nominal 

mass-to-charge ratio and which cannot be resolved by the mass 

spectrometer in use. All elements determined by this method have, at a 

minimum, one isotope free of isobaric elemental interference. Of the 

analytical isotopes recommended for use with this method (Table 4), only 

molybdenum-98 (ruthenium) and selenium-82 (krypton) have isobaric 

elemental interferences. If alternative analytical isotopes having higher 

200.8-6
 
natural abundance are selected in order to achieve greater sensitivity, an 

isobaric interference may occur. All data obtained under such conditions 

must be corrected by measuring the signal from another isotope of the 

interfering element and subtracting the appropriate signal ratio from the 

isotope of interest. A record of this correction process should be included 

with the report of the data. It should be noted that such corrections will 

only be as accurate as the accuracy of the isotope ratio used in the 

elemental equation for data calculations. Relevant isotope ratios should 

be established prior to the application of any corrections. 

4.1.2	 Abundance sensitivity - Is a property defining the degree to which the 

wings of a mass peak contribute to adjacent masses. The abundance 

sensitivity is affected by ion energy and quadrupole operating pressure. 

Wing overlap interferences may result when a small ion peak is being 

measured adjacent to a large one. The potential for these interferences 

should be recognized and the spectrometer resolution adjusted to 

minimize them. 

4.1.3 Isobaric polyatomic ion interferences - Are caused by ions consisting of 

more than one atom which have the same nominal mass-to-charge ratio 

as the isotope of interest, and which cannot be resolved by the mass 

spectrometer in use. These ions are commonly formed in the plasma or 

interface system from support gases or sample components. Most of the 

3 common interferences have been identified , and these are listed in Table2

together with the method elements affected. Such interferences must be 

recognized, and when they cannot be avoided by the selection of 

alternative analytical isotopes, appropriate corrections must be made to 

the data. Equations for the correction of data should be established at the 

time of the analytical run sequence as the polyatomic ion interferences will 

be highly dependent on the sample matrix and chosen instrument 

conditions. In particular, the common 82Kr interference that affects the 

determination of both arsenic and selenium, can be greatly reduced with 

the use of high purity krypton free argon. 

4.1.4	 Physical interferences - Are associated with the physical processes which 

govern the transport of sample into the plasma, sample conversion 

processes in the plasma, and the transmission of ions through the plasmamass spectrometer interface. These interferences may result in differences 

between instrument responses for the sample and the calibration 

standards. Physical interferences may occur in the transfer of solution to 

the nebulizer (e.g., viscosity effects), at the point of aerosol formation and 

transport to the plasma (e.g., surface tension), or during excitation and 

ionization processes within the plasma itself. High levels of dissolved 

solids in the sample may contribute deposits of material on the extraction 

and/or skimmer cones reducing the effective diameter of the orifices and 

therefore ion transmission. Dissolved solids levels not exceeding 

0.2% (w/v) have been recommended3 to reduce such effects. Internal 

standardization may be effectively used to compensate for many physical 

interference effects.4 Internal standards ideally should have similar 

200.8-7
 
analytical behavior to the elements being determined. 

4.1.5	 Memory interferences - Result when isotopes of elements in a previous 

sample contribute to the signals measured in a new sample. Memory 

effects can result from sample deposition on the sampler and skimmer 

cones, and from the buildup of sample material in the plasma torch and 

spray chamber. The site where these effects occur is dependent on the 

element and can be minimized by flushing the system with a rinse blank 

between samples (Section 7.6.3). The possibility of memory interferences 

should be recognized within an analytical run and suitable rinse times 

should be used to reduce them. The rinse times necessary for a particular 

element should be estimated prior to analysis. This may be achieved by 

aspirating a standard containing elements corresponding to 10 times the 

upper end of the linear range for a normal sample analysis period, 

followed by analysis of the rinse blank at designated intervals. The length 

of time required to reduce analyte signals to within a factor of 10 of the 

method detection limit, should be noted. Memory interferences may also 

be assessed within an analytical run by using a minimum of three 

replicate integrations for data acquisition. If the integrated signal values 

drop consecutively, the analyst should be alerted to the possibility of a 

memory effect, and should examine the analyte concentration in the 

previous sample to identify if this was high. If a memory interference is 

suspected, the sample should be reanalyzed after a long rinse period. In 

the determination of mercury, which suffers from severe memory effects, 

the addition of 100 μg/L gold will effectively rinse 5 μg/L mercury in 

approximately two minutes. Higher concentrations will require a longer 

rinse time. 

5.0	 SAFETY 

5.1	 The toxicity or carcinogenicity of reagents used in this method have not been fully 

established. Each chemical should be regarded as a potential health hazard and 

exposure to these compounds should be as low as reasonably achievable. Each 

laboratory is responsible for maintaining a current awareness file of OSHA 

regulations regarding the safe handling of the chemicals specified in this 

method.5,8 A reference file of material data handling sheets should also be 

available to all personnel involved in the chemical analysis. Specifically, 

concentrated nitric and hydrochloric acids present various hazards and are 

moderately toxic and extremely irritating to skin and mucus membranes. Use 

these reagents in a fume hood whenever possible and if eye or skin contact 

occurs, flush with large volumes of water. Always wear safety glasses or a shield 

for eye protection, protective clothing and observe proper mixing when working 

with these reagents. 

5.2	 The acidification of samples containing reactive materials may result in the release 

of toxic gases, such as cyanides or sulfides. Acidification of samples should be 

done in a fume hood. 

5.3	 All personnel handling environmental samples known to contain or to have been 

200.8-8
 
in contact with human waste should be immunized against known disease 

causative agents. 

5.4	 Analytical plasma sources emit radiofrequency radiation in addition to intense UV 

radiation. Suitable precautions should be taken to protect personnel from such 

hazards. The inductively coupled plasma should only be viewed with proper eye 

protection from UV emissions. 

5.5	 It is the responsibility of the user of this method to comply with relevant disposal 

and waste regulations. For guidance see Sections 14.0 and 15.0. 

6.0	 EQUIPMENT AND SUPPLIES 

6.1 Inductively coupled plasma mass spectrometer: 

6.1.1	 Instrument capable of scanning the mass range 5-250 amu with a 

minimum resolution capability of 1 amu peak width at 5% peak height. 

Instrument may be fitted with a conventional or extended dynamic range 

detection system. 

Note: If an electron multiplier detector is being used, precautions should 

be taken, where necessary, to prevent exposure to high ion flux. 

Otherwise changes in instrument response or damage to the multiplier 

may result. 

6.1.2	 Radio-frequency generator compliant with FCC regulations. 

6.1.3	 Argon gas supply - High purity grade (99.99%). When analyses are 

conducted frequently, liquid argon is more economical and requires less 

frequent replacement of tanks than compressed argon in conventional 

cylinders (Section 4.1.3). 

6.1.4	 A variable-speed peristaltic pump is required for solution delivery to the 

nebulizer. 

6.1.5	 A mass-flow controller on the nebulizer gas supply is required. A watercooled spray chamber may be of benefit in reducing some types of 

interferences (e.g., from polyatomic oxide species). 

6.1.6	 If an electron multiplier detector is being used, precautions should be 

taken, where necessary, to prevent exposure to high ion flux. Otherwise 

changes in instrument response or damage to the multiplier may result. 

Samples having high concentrations of elements beyond the linear range 

of the instrument and with isotopes falling within scanning windows 

should be diluted prior to analysis. 

6.2	 Analytical balance, with capability to measure to 0.1 mg, for use in weighing 

solids, for preparing standards, and for determining dissolved solids in digests 

or extracts. 

200.8-9
 
6.3 A temperature adjustable hot plate capable of maintaining a temperature of 95°C. 

6.4	 (Optional) A temperature adjustable block digester capable of maintaining a 

temperature of 95°C and equipped with 250 mL constricted digestion tubes. 

6.5	 (Optional) A steel cabinet centrifuge with guard bowl, electric timer and brake. 

6.6	 A gravity convection drying oven with thermostatic control capable of 

maintaining 105°C ± 5°C. 

6.7	 (Optional) An air displacement pipetter capable of delivering volumes ranging 

from 0.1-2500 μL with an assortment of high quality disposable pipet tips. 

6.8	 Mortar and pestle, ceramic or nonmetallic material. 

6.9	 Polypropylene sieve, 5-mesh (4 mm opening). 

6.10	 Labware - For determination of trace levels of elements, contamination and loss 

are of prime consideration. Potential contamination sources include improperly 

cleaned laboratory apparatus and general contamination within the laboratory 

environment from dust, etc. A clean laboratory work area designated for trace 

element sample handling must be used. Sample containers can introduce positive 

and negative errors in the determination of trace elements by (1) contributing 

contaminants through surface desorption or leaching, (2) depleting element 

concentrations through adsorption processes. All reusable labware (glass, quartz, 

polyethylene, PTFE, FEP, etc.) should be sufficiently clean for the task objectives. 

Several procedures found to provide clean labware include soaking overnight and 

thoroughly washing with laboratory-grade detergent and water, rinsing with tap 

water, and soaking for four hours or more in 20% (V/V) nitric acid or a mixture 

of dilute nitric and hydrochloric acid (1+2+9), followed by rinsing with reagent 

grade water and storing clean. 

Note: Chromic acid must not be used for cleaning glassware. 

6.10.1	 Glassware - Volumetric flasks, graduated cylinders, funnels and centrifuge 

tubes (glass and/or metal free plastic). 

6.10.2	 Assorted calibrated pipettes. 

6.10.3	 Conical Phillips beakers (Corning 1080-250 or equivalent), 250 mL with 

50 mm watch glasses. 

6.10.4	 Griffin beakers, 250 mL with 75 mm watch glasses and (optional) 75 mm 

ribbed watch glasses. 

6.10.5	 (Optional) PTFE and/or quartz beakers, 250 mL with PTFE covers. 

6.10.6	 Evaporating dishes or high-form crucibles, porcelain, 100 mL capacity. 

200.8-10
 
6.10.7	 Narrow-mouth storage bottles, FEP (fluorinated ethylene propylene) with 

ETFE (ethylene tetrafluorethylene) screw closure, 125-250 mL capacities. 

6.10.8	 One-piece stem FEP wash bottle with screw closure, 125 mL capacity. 

7.0	 REAGENTS AND STANDARDS 

7.1	 Reagents may contain elemental impurities that might affect the integrity of 

analytical data. Owing to the high sensitivity of ICP-MS, high-purity reagents 

should be used whenever possible. All acids used for this method must be of 

ultra high-purity grade. Suitable acids are available from a number of 

manufacturers or may be prepared by sub-boiling distillation. Nitric acid is 

preferred for ICP-MS in order to minimize polyatomic ion interferences. Several 

polyatomic ion interferences result when hydrochloric acid is used (Table 2), 

however, it should be noted that hydrochloric acid is required to maintain 

stability in solutions containing antimony and silver. When hydrochloric acid is 

used, corrections for the chloride polyatomic ion interferences must be applied to 

all data. 

7.1.1	 Nitric acid, concentrated (sp.gr. 1.41). 

7.1.2	 Nitric acid (1+1) - Add 500 mL conc. nitric acid to 400 mL of regent grade 

water and dilute to 1 L. 

7.1.3	 Nitric acid (1+9) - Add 100 mL conc. nitric acid to 400 mL of reagent 

grade water and dilute to 1 L. 

7.1.4	 Hydrochloric acid, concentrated (sp.gr. 1.19). 

7.1.5	 Hydrochloric acid (1+1) - Add 500 mL conc. hydrochloric acid to 400 mL 

of reagent grade water and dilute to 1 L. 

7.1.6	 Hydrochloric acid (1+4) - Add 200 mL conc. hydrochloric acid to 400 mL 

of reagent grade water and dilute to 1 L. 

7.1.7	 Ammonium hydroxide, concentrated (sp.gr. 0.902). 

7.1.8	 Tartaric acid (CASRN 87-69-4). 

7.2	 Reagent water - All references to reagent grade water in this method refer to 

ASTM Type I water (ASTM D1193).9 Suitable water may be prepared by passing 

distilled water through a mixed bed of anion and cation exchange resins. 

7.3	 Standard Stock Solutions - Stock standards may be purchased from a reputable 

commercial source or prepared from ultra high-purity grade chemicals or metals 

(99.99-99.999% pure). All salts should be dried for one hour at 105°C, unless 

otherwise specified. Stock solutions should be stored in FEP bottles. Replace 

stock standards when succeeding dilutions for preparation of the multielement 

stock standards can not be verified. 

200.8-11
 
CAUTION:	 Many metal salts are extremely toxic if inhaled or swallowed. 

Wash hands thoroughly after handling. 

The following procedures may be used for preparing standard stock solutions: 

Note: Some metals, particularly those which form surface oxides require cleaning 

prior to being weighed. This may be achieved by pickling the surface of the 

metal in acid. An amount in excess of the desired weight should be pickled 

repeatedly, rinsed with water, dried and weighed until the desired weight is 

achieved. 

7.3.1	 Aluminum solution, stock 1 mL = 1000 μg Al: Pickle aluminum metal in 

warm (1+1) HCl to an exact weight of 0.100 g. Dissolve in 10 mL conc. 

HCl and 2 mL conc. nitric acid, heating to effect solution. Continue 

heating until volume is reduced to 4 mL. Cool and add 4 mL reagent 

grade water. Heat until the volume is reduced to 2 mL. Cool and dilute 

to 100 mL with reagent grade water. 

7.3.2	 Antimony solution, stock 1 mL = 1000 μg Sb: Dissolve 0.100 g antimony 

powder in 2 mL (1+1) nitric acid and 0.5 mL conc. hydrochloric acid, 

heating to effect solution. Cool, add 20 mL reagent grade water and 

0.15 g tartaric acid. Warm the solution to dissolve the white precipitate. 

Cool and dilute to 100 mL with reagent grade water. 

7.3.3	 Arsenic solution, stock 1 mL = 1000 μg As: Dissolve 0.1320 g As O2 3 in a 

mixture of 50 mL reagent grade water and 1 mL conc. ammonium 

hydroxide. Heat gently to dissolve. Cool and acidify the solution with 

2 mL conc. nitric acid. Dilute to 100 mL with reagent grade water. 

7.3.4	 Barium solution, stock 1 mL = 1000 μg Ba: Dissolve 0.1437 g BaCO3 in a 

solution mixture of 10 mL reagent grade water and 2 mL conc. nitric acid. 

Heat and stir to effect solution and degassing. Dilute to 100 mL with 

reagent grade water. 

7.3.5	 Beryllium solution, stock 1 mL = 1000 μg Be: Dissolve 1.965 g 

BeSO4•••4H 2 O (DO NOT DRY) in 50 mL reagent grade water. Add 1 mL 

conc. nitric acid. Dilute to 100 mL with reagent grade water. 

7.3.6	 Bismuth solution, stock 1 mL = 1000 μg Bi: Dissolve 0.1115 g Bi O3 2 in

5 mL conc. nitric acid. Heat to effect solution. Cool and dilute to 100 mL 

with reagent grade water. 

7.3.7	 Cadmium solution, stock 1 mL = 1000 μg Cd: Pickle cadmium metal in 

(1+9) nitric acid to an exact weight of 0.100 g. Dissolve in 5 mL (1+1) 

nitric acid, heating to effect solution. Cool and dilute to 100 mL with 

reagent grade water. 

7.3.8	 Chromium solution, stock 1 mL = 1000 μg Cr: Dissolve 0.1923 g CrO3 in 

a solution mixture of 10 mL reagent grade water and 1 mL conc. nitric 

200.8-12
 
acid. Dilute to 100 mL with reagent grade water. 

7.3.9	 Cobalt solution, stock 1 mL = 1000 μg Co: Pickle cobalt metal in (1+9) 

nitric acid to an exact weight of 0.100 g. Dissolve in 5 mL (1+1) nitric 

acid, heating to effect solution. Cool and dilute to 100 mL with reagent 

grade water. 

7.3.10	 Copper solution, stock 1 mL = 1000 μg Cu: Pickle copper metal in (1+9) 

nitric acid to an exact weight of 0.100 g. Dissolve in 5 mL (1+1) nitric 

acid, heating to effect solution. Cool and dilute to 100 mL with reagent 

grade water. 

7.3.11	 Gold solution, stock 1 mL = 1000 μg Au: Dissolve 0.100 g high purity 

(99.9999%) Au shot in 10 mL of hot conc. nitric acid by dropwise addition 

of 5 mL conc. HCl and then reflux to expel oxides of nitrogen and 

chlorine. Cool and dilute to 100 mL with reagent grade water. 

7.3.12	 Indium solution, stock 1 mL = 1000 μg In: Pickle indium metal in (1+1) 

nitric acid to an exact weight of 0.100 g. Dissolve in 10 mL (1+1) nitric 

acid, heating to effect solution. Cool and dilute to 100 mL with reagent 

grade water. 

7.3.13	 Lead solution, stock 1 mL = 1000 μg Pb: Dissolve 0.1599 g PbNO in 5 mL 3 

(1+1) nitric acid. Dilute to 100 mL with reagent grade water. 

7.3.14	 Magnesium solution, stock 1 mL = 1000 μg Mg: Dissolve 0.1658 g MgO 

in 10 mL (1+1) nitric acid, heating to effect solution. Cool and dilute to 

100 mL with reagent grade water. 

7.3.15	 Manganese solution, stock 1 mL = 1000 μg Mn: Pickle manganese flake 

in (1+9) nitric acid to an exact weight of 0.100 g. Dissolve in 5 mL (1+1) 

nitric acid, heating to effect solution. Cool and dilute to 100 mL with 

reagent grade water. 

7.3.16	 Mercury solution, stock, 1 mL = 1000 μg Hg: DO NOT DRY. CAUTION: 

highly toxic element. Dissolve 0.1354 g HgCl in reagent water. Add 2 

5.0 mL concentrated HNO3 and dilute to 100 mL with reagent water. 

7.3.17	 Molybdenum solution, stock 1 mL = 1000 μg Mo: Dissolve 0.1500 g MoO3 

in a solution mixture of 10 mL reagent grade water and 1 mL conc. 

ammonium hydroxide., heating to effect solution. Cool and dilute to 

100 mL with reagent grade water. 

7.3.18	 Nickel solution, stock 1 mL = 1000 μg Ni: Dissolve 0.100 g nickel powder 

in 5 mL conc. nitric acid, heating to effect solution. Cool and dilute to 

100 mL with reagent grade water. 

7.3.19	 Scandium solution, stock 1 mL = 1000 μg Sc: Dissolve 0.1534 g Sc O in 2 3 

5 mL (1+1) nitric acid, heating to effect solution. Cool and dilute to 

200.8-13
 
 

100 mL with reagent grade water. 

7.3.20	 Selenium solution, stock 1 mL = 1000 μg Se: Dissolve 0.1405 g SeO2 in 

20 mL ASTM Type I water. Dilute to 100 mL with reagent grade water. 

7.3.21	 Silver solution, stock 1 mL = 1000 μg Ag: Dissolve 0.100 g silver metal in 

5 mL (1+1) nitric acid, heating to effect solution. Cool and dilute to 

100 mL with reagent grade water. Store in dark container. 

7.3.22	 Terbium solution, stock 1 mL = 1000 μg Tb: Dissolve 0.1176 g Tb O4 7 in 

5 mL conc. nitric acid, heating to effect solution. Cool and dilute to 

100 mL with reagent grade water. 

7.3.23	 Thallium solution, stock 1 mL = 1000 μg Tl: Dissolve 0.1303 g TlNO3 in 

a solution mixture of 10 mL reagent grade water and 1 mL conc. nitric 

acid. Dilute to 100 mL with reagent grade water. 

7.3.24	 Thorium solution, stock 1 mL = 1000 μg Th: Dissolve 0.2380 g 

Th(NO ) 34 •4H2 O (DO NOT DRY) in 20 mL reagent grade water. Dilute to

100 mL with reagent grade water. 

7.3.25	 Uranium solution, stock 1 mL = 1000 μg U: Dissolve 0.2110 g 

UO2(NO3)2•6H2O (DO NOT DRY) in 20 mL reagent grade water and dilute 

to 100 mL with reagent grade water. 

7.3.26	 Vanadium solution, stock 1 mL = 1000 μg V: Pickle vanadium metal in 

(1+9) nitric acid to an exact weight of 0.100 g. Dissolve in 5 mL (1+1) 

nitric acid, heating to effect solution. Cool and dilute to 100 mL with 

reagent grade water. 

7.3.27	 Yttrium solution, stock 1 mL = 1000 μg Y: Dissolve 0.1270 g Y O in 5 mL 2 3 

(1+1) nitric acid, heating to effect solution. Cool and dilute to 100 mL 

with reagent grade water. 

7.3.28	 Zinc solution, stock 1 mL = 1000 μg Zn: Pickle zinc metal in (1+9) nitric 

acid to an exact weight of 0.100 g. Dissolve in 5 mL (1+1) nitric acid, 

heating to effect solution. Cool and dilute to 100 mL with reagent grade 

water. 

7.4	 Multielement Stock Standard Solutions - Care must be taken in the preparation 

of multielement stock standards that the elements are compatible and stable. 

Originating element stocks should be checked for the presence of impurities 

which might influence the accuracy of the standard. Freshly prepared standards 

should be transferred to acid cleaned, not previously used FEP fluorocarbon 

bottles for storage and monitored periodically for stability. The following 

combinations of elements are suggested: 

200.8-14
 
Standard Solution A	 Standard Solution B 

Aluminum Mercury Barium
 

Antimony Molybdenum Silver
 

Arsenic Nickel
 

Beryllium Selenium
 

Cadmium Thallium
 

Chromium Thorium
 

Cobalt Uranium
 

Copper Vanadium
 

Lead Zinc
 

Manganese
 

Except for selenium and mercury, multielement stock standard solutions A and 

B (1 mL = 10 μg) may be prepared by diluting 1.0 mL of each single element 

stock standard in the combination list to 100 mL with reagent water containing 

1% (v/v) nitric acid. For mercury and selenium in solution A, aliquots of 0.05 mL 

and 5.0 mL of the respective stock standards should be diluted to the specified 

100 mL (1 ml = 0.5 μg Hg and 50 μg Se). Replace the multielement stock 

standards when succeeding dilutions for preparation of the calibration standards 

cannot be verified with the quality control sample. 

7.4.1	 Preparation of calibration standards - fresh multielement calibration 

standards should be prepared every two weeks or as needed. Dilute each 

of the stock multielement standard solutions A and B to levels appropriate 

to the operating range of the instrument using reagent water containing 

1% (v/v) nitric acid. The element concentrations in the standards should 

be sufficiently high to produce good measurement precision and to 

accurately define the slope of the response curve. Depending on the 

sensitivity of the instrument, concentrations ranging from 10-200 μg/L are 

suggested, except mercury, which should be limited to ≤5 μg/L. It should 

be noted the selenium concentration is always a factor of 5 greater than 

the other analytes. If the direct addition procedure is being used (Method 

A, Section 10.3), add internal standards (Section 7.5) to the calibration 

standards and store in FEP bottles. Calibration standards should be 

verified initially using a quality control sample (Section 7.8). 

7.5	 Internal Standards Stock Solution - 1 mL = 100 μg. Dilute 10 mL of scandium, 

yttrium, indium, terbium and bismuth stock standards (Section 7.3) to 100 mL 

with reagent water, and store in a FEP bottle. Use this solution concentrate for 

addition to blanks, calibration standards and samples, or dilute by an appropriate 

amount using 1% (v/v) nitric acid, if the internal standards are being added by 

peristaltic pump (Method B, Section 10.3). 

Note: If mercury is to be determined by the "direct analysis" procedure, add an 

aliquot of the gold stock standard (Section 7.3.11) to the internal standard solution 

sufficient to provide a concentration of 100 μg/L in final the dilution of all blanks, 

calibration standards, and samples. 

200.8-15
 
7.6	 Blanks - Three types of blanks are required for this method. A calibration blank 

is used to establish the analytical calibration curve, the laboratory reagent blank 

is used to assess possible contamination from the sample preparation procedure 

and to assess spectral background and the rinse blank is used to flush the 

instrument between samples in order to reduce memory interferences. 

7.6.1	 Calibration blank - Consists of 1% (v/v) nitric acid in reagent grade water. 

If the direct addition procedure (Method A, Section 10.3) is being used, 

add internal standards. 

7.6.2	 Laboratory reagent blank (LRB) - Must contain all the reagents in the same 

volumes as used in processing the samples. The LRB must be carried 

through the same entire preparation scheme as the samples including 

digestion, when applicable. If the direct addition procedure (Method A, 

Section 10.3) is being used, add internal standards to the solution after 

preparation is complete. 

7.6.3	 Rinse blank - Consists of 2% (v/v) nitric acid in reagent grade water. 

Note: If mercury is to be determined by the "direct analysis" procedure, 

add gold (Section 7.3.11) to the rinse blank to a concentration of 100 μg/L. 

7.7	 Tuning Solution - This solution is used for instrument tuning and mass calibration 

prior to analysis. The solution is prepared by mixing beryllium, magnesium, 

cobalt, indium and lead stock solutions (Section 7.3) in 1% (v/v) nitric acid to 

produce a concentration of 100 μg/L of each element. Internal standards are not 

added to this solution. (Depending on the sensitivity of the instrument, this 

solution may need to be diluted 10-fold.) 

7.8	 Quality Control Sample (QCS) - The QCS should be obtained from a source 

outside the laboratory. The concentration of the QCS solution analyzed will 

depend on the sensitivity of the instrument. To prepare the QCS dilute an 

appropriate aliquot of analytes to a concentration ≤100 μg/L in 1% (v/v) nitric 

acid. Because of lower sensitivity, selenium may be diluted to a concentration of 

<500 μg/L, however, in all cases, mercury should be limited to a concentration 

of ≤5 μg/L. If the direct addition procedure (Method A, Section 10.3) is being 

used, add internal standards after dilution, mix and store in a FEP bottle. The 

QCS should be analyzed as needed to meet data-quality needs and a fresh 

solution should be prepared quarterly or more frequently as needed. 

7.9	 Laboratory Fortified Blank (LFB) - To an aliquot of LRB, add aliquots from 

multielement stock standards A and B (Section 7.4) to prepared the LFB. 

Depending on the sensitivity of the instrument, the fortified concentration used 

should range from 40-100 μg/L for each analyte, except selenium and mercury. 

For selenium the concentration should range from 200-500 μg/L, while the 

concentration range mercury should be limited to 2-5 μg/L. The LFB must be 

carried through the same entire preparation scheme as the samples including 

sample digestion, when applicable. If the direct addition procedure (Method A, 

Section 10.3) is being used, add internal standards to this solution after 

200.8-16
 
preparation has been completed. 

8.0	 SAMPLE COLLECTION, PRESERVATION, AND STORAGE 

8.1	 Prior to the collection of an aqueous sample, consideration should be given to the 

type of data required, (i.e., dissolved or total recoverable), so that appropriate 

preservation and pretreatment steps can be taken. The pH of all aqueous samples 

must be tested immediately prior to aliquoting for processing or "direct analysis" 

to ensure the sample has been properly preserved. If properly acid preserved, the 

sample can be held up to 6 months before analysis. 

8.2	 For the determination of dissolved elements, the sample must be filtered through 

a 0.45 μm pore diameter membrane filter at the time of collection or as soon 

thereafter as practically possible. Use a portion of the sample to rinse the filter 

flask, discard this portion and collect the required volume of filtrate. Acidify the 

filtrate with (1+1) nitric acid immediately following filtration to pH <2. 

8.3	 For the determination of total recoverable elements in aqueous samples, samples 

are not filtered, but acidified with (1+1) nitric acid to pH <2 (normally, 3 mL of 

(1+1) acid per liter of sample is sufficient for most ambient and drinking water 

samples). Preservation may be done at the time of collection, however, to avoid 

the hazards of strong acids in the field, transport restrictions, and possible 

contamination it is recommended that the samples be returned to the laboratory 

within two weeks of collection and acid preserved upon receipt in the laboratory. 

Following acidification, the sample should be mixed, held for 16 hours, and then 

verified to be pH <2 just prior withdrawing an aliquot for processing or "direct 

analysis". If for some reason such as high alkalinity the sample pH is verified to 

be >2, more acid must be added and the sample held for 16 hours until verified 

to be pH <2. See Section 8.1. 

Note: When the nature of the sample is either unknown or known to be 

hazardous, acidification should be done in a fume hood. See Section 5.2. 

8.4	 Solid samples require no preservation prior to analysis other than storage at 4°C. 

There is no established holding time limitation for solid samples. 

8.5	 For aqueous samples, a field blank should be prepared and analyzed as required 

by the data user. Use the same container and acid as used in sample collection. 

9.0	 QUALITY CONTROL 

9.1	 Each laboratory using this method is required to operate a formal quality control 

(QC) program. The minimum requirements of this program consist of an initial 

demonstration of laboratory capability, and the periodic analysis of laboratory 

reagent blanks, fortified blanks and calibration solutions as a continuing check on 

performance. The laboratory is required to maintain performance records that 

define the quality of the data thus generated. 

9.2	 Initial Demonstration of Performance (mandatory) 

200.8-17
 
9.2.1	 The initial demonstration of performance is used to characterize 

instrument performance (determination of linear calibration ranges and 

analysis of quality control samples) and laboratory performance 

(determination of method detection limits) prior to analyses conducted by 

this method. 

9.2.2	 Linear calibration ranges - Linear calibration ranges are primarily detector 

limited. The upper limit of the linear calibration range should be 

established for each analyte by determining the signal responses from a 

minimum of three different concentration standards, one of which is close 

to the upper limit of the linear range. Care should be taken to avoid 

potential damage to the detector during this process. The linear 

calibration range which may be used for the analysis of samples should 

be judged by the analyst from the resulting data. The upper LDR limit 

should be an observed signal no more than 10% below the level 

extrapolated from lower standards. Determined sample analyte 

concentrations that are greater than 90% of the determined upper LDR 

limit must be diluted and reanalyzed. The LDRs should be verified 

whenever, in the judgement of the analyst, a change in analytical 

performance caused by either a change in instrument hardware or 

operating conditions would dictate they be redetermined. 

9.2.3	 Quality control sample (QCS) - When beginning the use of this method, 

on a quarterly basis or as required to meet data-quality needs, verify the 

calibration standards and acceptable instrument performance with the 

preparation and analyses of a QCS (Section 7.8). To verify the calibration 

standards the determined mean concentration from three analyses of the 

QCS must be within ±10% of the stated QCS value. If the QCS is used for 

determining acceptable on-going instrument performance, analysis of the 

QCS prepared to a concentration of 100 μg/L must be within ±10% of the 

stated value or within the acceptance limits listed in Table 8, whichever 

is the greater. (If the QCS is not within the required limits, an immediate 

second analysis of the QCS is recommended to confirm unacceptable 

performance.) If the calibration standards and/or acceptable instrument 

performance cannot be verified, the source of the problem must be 

identified and corrected before either proceeding on with the initial 

determination of method detection limits or continuing with on-going 

analyses. 

9.2.4	 Method detection limits (MDL) should be established for all analytes, 

using reagent water (blank) fortified at a concentration of two to five times 

the estimated detection limit.7 To determine MDL values, take seven 

replicate aliquots of the fortified reagent water and process through the 

entire analytical method. Perform all calculations defined in the method 

and report the concentration values in the appropriate units. Calculate the 

MDL as follows: 

200.8-18
 
where: 

t =	 Student's t value for a 99% confidence level and a standard 

deviation estimate with n-1 degrees of freedom [t = 3.14 for 

seven replicates] 

S =	 standard deviation of the replicate analyses 

Note: If additional confirmation is desired, reanalyze the seven replicate 

aliquots on two more nonconsecutive days and again calculate the MDL 

values for each day. An average of the three MDL values for each analyte 

may provide for a more appropriate MDL estimate. If the relative 

standard deviation (RSD) from the analyses of the seven aliquots is <10%, 

the concentration used to determine the analyte MDL may have been 

inappropriately high for the determination. If so, this could result in the 

calculation of an unrealistically low MDL. Concurrently, determination 

of MDL in reagent water represents a best case situation and does not 

reflect possible matrix effects of real world samples. However, successful 

analyses of LFMs (Section 9.4) can give confidence to the MDL value 

determined in reagent water. Typical single laboratory MDL values using 

this method are given in Table 7. 

The MDLs must be sufficient to detect analytes at the required levels 

according to compliance monitoring regulation (Section 1.2). MDLs 

should be determined annually, when a new operator begins work or 

whenever, in the judgement of the analyst, a change in analytical 

performance caused by either a change in instrument hardware or 

operating conditions would dictate they be redetermined. 

9.3	 Assessing Laboratory Performance (mandatory) 

9.3.1	 Laboratory reagent blank (LRB) - The laboratory must analyze at least one 

LRB (Section 7.6.2) with each batch of 20 or fewer of samples of the same 

matrix. LRB data are used to assess contamination from the laboratory 

environment and to characterize spectral background from the reagents 

used in sample processing. LRB values that exceed the MDL indicate 

laboratory or reagent contamination should be suspected. When LRB 

values constitute 10% or more of the analyte level determined for a sample 

or is 2.2 times the analyte MDL whichever is greater, fresh aliquots of the 

samples must be prepared and analyzed again for the affected analytes 

after the source of contamination has been corrected and acceptable LRB 

values have been obtained. 

9.3.2	 Laboratory fortified blank (LFB) - The laboratory must analyze at least one 

LFB (Section 7.9) with each batch of samples. Calculate accuracy as 

percent recovery using the following equation: 

200.8-19
 
where: 

R = percent recovery 

LFB = laboratory fortified blank 

LRB = laboratory reagent blank 

s = concentration equivalent of analyte added to fortify the 

LBR solution 

If the recovery of any analyte falls outside the required control limits of 

85-115%, that analyte is judged out of control, and the source of the 

problem should be identified and resolved before continuing analyses. 

9.3.3	 The laboratory must use LFB analyses data to assess laboratory 

performance against the required control limits of 85-115% (Section 9.3.2). 

When sufficient internal performance data become available (usually a 

minimum of 20-30 analyses), optional control limits can be developed from 

the mean percent recovery (x) and the standard deviation (S) of the mean 

percent recovery. These data can be used to establish the upper and lower 

control limits as follows: 

UPPER CONTROL LIMIT = x + 3S 

LOWER CONTROL LIMIT = x - 3S 

The optional control limits must be equal to or better than the required 

control limits of 85-115%. After each five to ten new recovery 

measurements, new control limits can be calculated using only the most 

recent 20-30 data points. Also, the standard deviation (S) data should be 

used to establish an on-going precision statement for the level of 

concentrations included in the LFB. These data must be kept on file and 

be available for review. 

9.3.4	 Instrument performance - For all determinations the laboratory must check 

instrument performance and verify that the instrument is properly 

calibrated on a continuing basis. To verify calibration run the calibration 

blank and calibration standards as surrogate samples immediately 

following each calibration routine, after every ten analyses and at the end 

of the sample run. The results of the analyses of the standards will 

indicate whether the calibration remains valid. The analysis of all analytes 

within the standard solutions must be within ±10% of calibration. If the 

calibration cannot be verified within the specified limits, the instrument 

must be recalibrated. (The instrument responses from the calibration 

check may be used for recalibration purposes, however, it must be verified 

before continuing sample analysis.) If the continuing calibration check is 

not confirmed within ±15%, the previous 10 samples must be reanalyzed 

after recalibration. If the sample matrix is responsible for the calibration 

drift, it is recommended that the previous 10 samples are reanalyzed in 

groups of five between calibration checks to prevent a similar drift 

situation from occurring. 

9.4	 Assessing Analyte Recovery and Data Quality 

200.8-20
 
 

9.4.1	 Sample homogeneity and the chemical nature of the sample matrix can 

affect analyte recovery and the quality of the data. Taking separate 

aliquots from the sample for replicate and fortified analyses can in some 

cases assess the effect. Unless otherwise specified by the data user, 

laboratory or program, the following laboratory fortified matrix (LFM) 

procedure (Section 9.4.2) is required. 

9.4.2	 The laboratory must add a known amount of analyte to a minimum of 

10% of the routine samples. In each case the LFM aliquot must be a 

duplicate of the aliquot used for sample analysis and for total recoverable 

determinations added prior to sample preparation. For water samples, the 

added analyte concentration must be the same as that used in the 

laboratory fortified blank (Section 7.9). For solid samples, the 

concentration added should be 100 mg/kg equivalent (200 μg/L in the 

analysis solution) except silver which should be limited to 50 mg/kg 

(Section 1.8). Over time, samples from all routine sample sources should 

be fortified. 

9.4.3	 Calculate the percent recovery for each analyte, corrected for background 

concentrations measured in the unfortified sample, and compare these 

values to the designated LFM recovery range of 70-130%. Recovery 

calculations are not required if the concentration of the analyte added is 

less than 30% of the sample background concentration. Percent recovery 

may be calculated in units appropriate to the matrix, using the following 

equation: 

where: 

R = percent recovery 

Cs = fortified sample concentration 

C = sample background concentration 

s = concentration equivalent of analyte added to fortify the 

sample 

9.4.4	 If recovery of any analyte falls outside the designated range and 

laboratory performance for that analyte is shown to be in control 

(Section 9.3), the recovery problem encountered with the fortified sample 

is judged to be matrix related, not system related. The data user should 

be informed that the result for that analyte in the unfortified sample is 

suspect due to either the heterogeneous nature of the sample or an 

uncorrected matrix effect. 

9.4.5	 Internal standards responses - The analyst is expected to monitor the 

responses from the internal standards throughout the sample set being 

200.8-21
 
analyzed. Ratios of the internal standards responses against each other 

should also be monitored routinely. This information may be used to 

detect potential problems caused by mass dependent drift, errors incurred 

in adding the internal standards or increases in the concentrations of 

individual internal standards caused by background contributions from 

the sample. The absolute response of any one internal standard must not 

deviate more than 60-125% of the original response in the calibration 

blank. If deviations greater than these are observed, flush the instrument 

with the rinse blank and monitor the responses in the calibration blank. 

If the responses of the internal standards are now within the limit, take a 

fresh aliquot of the sample, dilute by a further factor of two, add the 

internal standards and reanalyze. If after flushing the response of the 

internal standards in the calibration blank are out of limits, terminate the 

analysis and determine the cause of the drift. Possible causes of drift may 

be a partially blocked sampling cone or a change in the tuning condition 

of the instrument. 

10.0	 CALIBRATION AND STANDARDIZATION 

10.1	 Operating conditions - Because of the diversity of instrument hardware, no 

detailed instrument operating conditions are provided. The analyst is advised to 

follow the recommended operating conditions provided by the manufacturer. It 

is the responsibility of the analyst to verify that the instrument configuration and 

operating conditions satisfy the analytical requirements and to maintain quality 

control data verifying instrument performance and analytical results. Instrument 

operating conditions which were used to generate precision and recovery data for 

this method (Section 13.0) are included in Table 6. 

10.2	 Precalibration routine - The following precalibration routine must be completed 

prior to calibrating the instrument until such time it can be documented with 

periodic performance data that the instrument meets the criteria listed below 

without daily tuning. 

10.2.1	 Initiate proper operating configuration of instrument and data system. 

Allow a period of not less than 30 minutes for the instrument to warm up. 

During this process conduct mass calibration and resolution checks using 

the tuning solution. Resolution at low mass is indicated by magnesium 

isotopes 24, 25, and 26. Resolution at high mass is indicated by lead 

isotopes 206, 207, and 208. For good performance adjust spectrometer 

resolution to produce a peak width of approximately 0.75 amu at 5% peak 

height. Adjust mass calibration if it has shifted by more than 0.1 amu 

from unit mass. 

10.2.2	 Instrument stability must be demonstrated by running the tuning solution 

(Section 7.7) a minimum of five times with resulting relative standard 

deviations of absolute signals for all analytes of less than 5%. 

10.3	 Internal Standardization - Internal standardization must be used in all analyses 

to correct for instrument drift and physical interferences. A list of acceptable 

200.8-22
 
internal standards is provided in Table 3. For full mass range scans, a minimum 

of three internal standards must be used. Procedures described in this method 

for general application, detail the use of five internal standards; scandium, 

yttrium, indium, terbium and bismuth. These were used to generate the precision 

and recovery data attached to this method. Internal standards must be present 

in all samples, standards and blanks at identical levels. This may be achieved by 

directly adding an aliquot of the internal standards to the CAL standard, blank 

or sample solution (Method A, Section 10.3), or alternatively by mixing with the 

solution prior to nebulization using a second channel of the peristaltic pump and 

a mixing coil (Method B, Section 10.3). The concentration of the internal standard 

should be sufficiently high that good precision is obtained in the measurement 

of the isotope used for data correction and to minimize the possibility of 

correction errors if the internal standard is naturally present in the sample. 

Depending on the sensitivity of the instrument, a concentration range of 20-200 

μg/L of each internal standard is recommended. Internal standards should be 

added to blanks, samples and standards in a like manner, so that dilution effects 

resulting from the addition may be disregarded. 

10.4	 Calibration - Prior to initial calibration, set up proper instrument software 

routines for quantitative analysis. The instrument must be calibrated using one 

of the internal standard routines (Method A or B) described in Section 10.3. The 

instrument must be calibrated for the analytes to be determined using the 

calibration blank (Section 7.6.1) and calibration standards A and B (Section 7.4.1) 

prepared at one or more concentration levels. A minimum of three replicate 

integrations are required for data acquisition. Use the average of the integrations 

for instrument calibration and data reporting. 

10.5	 The rinse blank should be used to flush the system between solution changes for 

blanks, standards and samples. Allow sufficient rinse time to remove traces of 

the previous sample (Section 4.1.5). Solutions should be aspirated for 30 seconds 

prior to the acquisition of data to allow equilibrium to be established. 

11.0	 PROCEDURE 

11.1	 Aqueous Sample Preparation - Dissolved Analytes 

11.1.1	 For the determination of dissolved analytes in ground and surface waters, 

pipet an aliquot (≥20 mL) of the filtered, acid preserved sample into a 

50 mL polypropylene centrifuge tube. Add an appropriate volume of 

(1+1) nitric acid to adjust the acid concentration of the aliquot to 

approximate a 1% (v/v) nitric acid solution (e.g., add 0.4 mL (1+1) HNO3 

to a 20 mL aliquot of sample). If the direct addition procedure 

(Method A, Section 10.3) is being used, add internal standards, cap the 

tube and mix. The sample is now ready for analysis (Section 1.2). 

Allowance for sample dilution should be made in the calculations. 

Note: If a precipitate is formed during acidification, transport, or storage, 

the sample aliquot must be treated using the procedure in Section 11.2 

prior to analysis. 

200.8-23
 
11.2	 Aqueous Sample Preparation - Total Recoverable Analytes 

11.2.1	 For the "direct analysis" of total recoverable analytes in drinking water 

samples containing turbidity <1 NTU, treat an unfiltered acid preserved 

sample aliquot using the sample preparation procedure described in 

Section 11.1.1 while making allowance for sample dilution in the data 

calculation. For the determination of total recoverable analytes in all other 

aqueous samples or for preconcentrating drinking water samples prior to 

analysis follow the procedure given in Sections 11.2.2 through 11.2.8. 

11.2.2	 For the determination of total recoverable analytes in aqueous samples 

(other than drinking water with <1 NTU turbidity), transfer a 100 mL 

(±1 mL) aliquot from a well mixed, acid preserved sample to a 250 mL 

Griffin beaker (Sections 1.2, 1.3, 1.7, and 1.8). (When necessary, smaller 

sample aliquot volumes may be used.) 

Note: If the sample contains undissolved solids >1%, a well mixed, acid 

preserved aliquot containing no more than 1 g particulate material should 

be cautiously evaporated to near 10 mL and extracted using the acidmixture procedure described in Sections 11.3.3 through 11.3.7. 

11.2.3	 Add 2 mL (1+1) nitric acid and 1.0 mL of (1+1) hydrochloric acid to the 

beaker containing the measured volume of sample. Place the beaker on 

the hot plate for solution evaporation. The hot plate should be located in 

a fume hood and previously adjusted to provide evaporation at a 

temperature of approximately but no higher than 85°C. (See the following 

note.) The beaker should be covered with an elevated watch glass or 

other necessary steps should be taken to prevent sample contamination 

from the fume hood environment. 

Note: For proper heating adjust the temperature control of the hot plate 

such that an uncovered Griffin beaker containing 50 mL of water placed 

in the center of the hot plate can be maintained at a temperature 

approximately but no higher than 85°C. (Once the beaker is covered with 

a watch glass the temperature of the water will rise to approximately 

95°C.) 

11.2.4	 Reduce the volume of the sample aliquot to about 20 mL by gentle heating 

at 85°C. DO NOT BOIL. This step takes about two hours for a 100 mL 

aliquot with the rate of evaporation rapidly increasing as the sample 

volume approaches 20 mL. (A spare beaker containing 20 mL of water 

can be used as a gauge.) 

11.2.5	 Cover the lip of the beaker with a watch glass to reduce additional 

evaporation and gently reflux the sample for 30 minutes. (Slight boiling 

may occur, but vigorous boiling must be avoided to prevent loss of the 

HCl-H O azeotrope.) 2 

11.2.6	 Allow the beaker to cool. Quantitatively transfer the sample solution to 

200.8-24
 
a 50 mL volumetric flask or 50 mL class A stoppered graduated cylinder, 

make to volume with reagent water, stopper and mix. 

11.2.7	 Allow any undissolved material to settle overnight, or centrifuge a portion 

of the prepared sample until clear. (If after centrifuging or standing 

overnight the sample contains suspended solids that would clog the 

nebulizer, a portion of the sample may be filtered for their removal prior 

to analysis. However, care should be exercised to avoid potential 

contamination from filtration.) 

11.2.8	 Prior to analysis, adjust the chloride concentration by pipetting 20 mL of 

the prepared solution into a 50 mL volumetric flask, dilute to volume with 

reagent water and mix. (If the dissolved solids in this solution are >0.2%, 

additional dilution may be required to prevent clogging of the extraction 

and/or skimmer cones. If the direct addition procedure (Method A, 

Section 10.3) is being used, add internal standards and mix. The sample 

is now ready for analysis. Because the effects of various matrices on the 

stability of diluted samples cannot be characterized, all analyses should be 

performed as soon as possible after the completed preparation. 

11.3	 Solid Sample Preparation - Total Recoverable Analytes 

11.3.1	 For the determination of total recoverable analytes in solid samples, mix 

the sample thoroughly and transfer a portion (>20 g) to tared weighing 

dish, weigh the sample and record the wet weight (WW). (For samples 

with <35% moisture a 20 g portion is sufficient. For samples with 

moisture >35% a larger aliquot 50-100 g is required.) Dry the sample to 

a constant weight at 60°C and record the dry weight (DW) for calculation 

of percent solids (Section 12.6). (The sample is dried at 60°C to prevent 

the loss of mercury and other possible volatile metallic compounds, to 

facilitate sieving, and to ready the sample for grinding.) 

11.3.2	 To achieve homogeneity, sieve the dried sample using a 5-mesh 

polypropylene sieve and grind in a mortar and pestle. (The sieve, mortar 

and pestle should be cleaned between samples.) From the dried, ground 

material weigh accurately a representative 1.0 ± 0.01 g aliquot (W) of the 

sample and transfer to a 250 mL Phillips beaker for acid extraction. 

11.3.3	 To the beaker add 4 mL of (1+1) HNO and 10 mL of (1+4) HCl. 3 Cover 

the lip of the beaker with a watch glass. Place the beaker on a hot plate 

for reflux extraction of the analytes. The hot plate should be located in a 

fume hood and previously adjusted to provide a reflux temperature of 

approximately 95°C. (See the following note.) 

Note: For proper heating adjust the temperature control of the hot plate 

such that an uncovered Griffin beaker containing 50 mL of water placed 

in the center of the hot plate can be maintained at a temperature 

approximately but no higher than 85°C. (Once the beaker is covered with 

a watch glass the temperature of the water will rise to approximately 

200.8-25
 
95°C.) Also, a block digester capable of maintaining a temperature of 

95°C and equipped with 250 mL constricted volumetric digestion tubes 

may be substituted for the hot plate and conical beakers in the extraction 

step. 

11.3.4	 Heat the sample and gently reflux for 30 minutes. Very slight boiling may 

occur, however vigorous boiling must be avoided to prevent loss of the 

HCl-H O azeotrope. Some solution evaporation will occur (3-4 mL). 2 

11.3.5	 Allow the sample to cool and quantitatively transfer the extract to a 

100 mL volumetric flask. Dilute to volume with reagent water, stopper 

and mix. 

11.3.6	 Allow the sample extract solution to stand overnight to separate insoluble 

material or centrifuge a portion of the sample solution until clear. (If after 

centrifuging or standing overnight the extract solution contains suspended 

solids that would clog the nebulizer, a portion of the extract solution may 

be filtered for their removal prior to analysis. However, care should be 

exercised to avoid potential contamination from filtration.) 

11.3.7	 Prior to analysis, adjust the chloride concentration by pipetting 20 mL of 

the prepared solution into a 100 mL volumetric flask, dilute to volume 

with reagent water and mix. (If the dissolved solids in this solution are 

>0.2%, additional dilution may be required to prevent clogging of the 

extraction and/or skimmer cones. If the direct addition procedure 

(Method A, Section 10.3) is being used, add internal standards and mix. 

The sample extract is now ready for analysis. Because the effects of 

various matrices on the stability of diluted samples cannot be 

characterized, all analyses should be performed as soon as possible after 

the completed preparation. 

Note: Determine the percent solids in the sample for use in calculations 

and for reporting data on a dry weight basis. 

11.4	 Sample Analysis 

11.4.1	 For every new or unusual matrix, it is highly recommended that a semiquantitative analysis be carried out to screen the sample for elements at 

high concentration. Information gained from this may be used to prevent 

potential damage to the detector during sample analysis and to identify 

elements which may be higher than the linear range. Matrix screening 

may be carried out by using intelligent software, if available, or by 

diluting the sample by a factor of 500 and analyzing in a semi-quantitative 

mode. The sample should also be screened for background levels of all 

elements chosen for use as internal standards in order to prevent bias in 

the calculation of the analytical data. 

11.4.2	 Initiate instrument operating configuration. Tune and calibrate the 

instrument for the analytes of interest (Section 10.0). 

200.8-26
 
11.4.3	 Establish instrument software run procedures for quantitative analysis. 

For all sample analyses, a minimum of three replicate integrations are 

required for data acquisition. Use the average of the integrations for data 

reporting. 

11.4.4	 All masses which might affect data quality must be monitored during the 

analytical run. As a minimum, those masses prescribed in Table 4 must 

be monitored in the same scan as is used for the collection of the data. 

This information should be used to correct the data for identified 

interferences. 

11.4.5	 During the analysis of samples, the laboratory must comply with the 

required quality control described in Sections 9.3 and 9.4. Only for the 

determination of dissolved analytes or the "direct analysis" of drinking 

water with turbidity of <1 NTU is the sample digestion step of the LRB, 

LFB, and LFM not required. 

11.4.6	 The rinse blank should be used to flush the system between samples. 

Allow sufficient time to remove traces of the previous sample or a 

minimum of one minute (Section 4.1.5). Samples should be aspirated for 

30 seconds prior to the collection of data. 

11.4.7	 Samples having concentrations higher than the established linear dynamic 

range should be diluted into range and reanalyzed. The sample should 

first be analyzed for the trace elements in the sample, protecting the 

detector from the high concentration elements, if necessary, by the 

selection of appropriate scanning windows. The sample should then be 

diluted for the determination of the remaining elements. Alternatively, 

the dynamic range may be adjusted by selecting an alternative isotope of 

lower natural abundance, provided quality control data for that isotope 

have been established. The dynamic range must not be adjusted by 

altering instrument conditions to an uncharacterized state. 

12.0	 DATA ANALYSIS AND CALCULATIONS 

12.1	 Elemental equations recommended for sample data calculations are listed in Table 

5. Sample data should be reported in units of μg/L for aqueous samples or 

mg/kg dry weight for solid samples. Do not report element concentrations below 

the determined MDL. 

12.2	 For data values less than 10, two significant figures should be used for reporting 

element concentrations. For data values greater than or equal to 10, three 

significant figures should be used. 

12.3	 For aqueous samples prepared by total recoverable procedure (Section 11.2), 

multiply solution concentrations by the dilution factor 1.25. If additional dilutions 

were made to any samples or an aqueous sample was prepared using the acidmixture procedure described in Section 11.3, the appropriate factor should be 

applied to the calculated sample concentrations. 

200.8-27
 
12.4	 For total recoverable analytes in solid samples (Section 11.3), round the solution 

analyte concentrations (μg/L in the analysis solution) as instructed in Section 12.2. 

Multiply the μ/L concentrations in the analysis solution by the factor 0.005 to 

calculate the mg/L analyte concentration in the 100 mL extract solution. (If 

additional dilutions were made to any samples, the appropriate factor should be 

applied to calculate analyte concentrations in the extract solution.) Report the 

data up to three significant figures as mg/kg dry-weight basis unless specified 

otherwise by the program or data user. Calculate the concentration using the 

equation below: 

where: 

C =	 Concentration in the extract (mg/L) 

V =	 Volume of extract (L, 100 mL = 0.1L) 

W =	 Weight of sample aliquot extracted (g x 0.001 = kg) 

Do not report analyte data below the estimated solids MDL or an adjusted MDL 

because of additional dilutions required to complete the analysis. 

12.5	 To report percent solids in solid samples (Sect. 11.3) calculate as follows: 

where: o DW = Sample weight (g) dried at 60 C

WW = Sample weight (g) before drying 

Note: If the data user, program or laboratory requires that the reported percent 

solids be determined by drying at 105°C, repeat the procedure given in 

Section 11.3 using a separate portion (>20 g) of the sample and dry to constant 

weight at 103-105°C. 

12.6	 Data values should be corrected for instrument drift or sample matrix induced 

interferences by the application of internal standardization. Corrections for 

characterized spectral interferences should be applied to the data. Chloride 

interference corrections should be made on all samples, regardless of the addition 

of hydrochloric acid, as the chloride ion is a common constituent of 

environmental samples. 

12.7	 If an element has more than one monitored isotope, examination of the 

concentration calculated for each isotope, or the isotope ratios, will provide useful 

information for the analyst in detecting a possible spectral interference. 

200.8-28
 
Consideration should therefore be given to both primary and secondary isotopes 

in the evaluation of the element concentration. In some cases, secondary isotopes 

may be less sensitive or more prone to interferences than the primary 

recommended isotopes, therefore differences between the results do not 

necessarily indicate a problem with data calculated for the primary isotopes. 

12.8	 The QC data obtained during the analyses provide an indication of the quality of 

the sample data and should be provided with the sample results. 

13.0	 METHOD PERFORMANCE 

13.1	 Instrument operating conditions used for single laboratory testing of the method 

are summarized in Table 6. Total recoverable digestion and "direct analysis" 

MDLs determined using the procedure described in Section 9.2.4, are listed in 

Table 7. 

13.2	 Data obtained from single laboratory testing of the method are summarized in 

Table 9 for five water samples representing drinking water, surface water, ground 

water and waste effluent. Samples were prepared using the procedure described 

in Section 11.2. For each matrix, five replicates were analyzed and the average 

of the replicates used for determining the sample background concentration for 

each element. Two further pairs of duplicates were fortified at different 

concentration levels. For each method element, the sample background 

concentration, mean percent recovery, the standard deviation of the percent 

recovery and the relative percent difference between the duplicate fortified 

samples are listed in Table 8. 

13.3	 Data obtained from single laboratory testing of the method are summarized in 

Table 10 for three solid samples consisting of SRM 1645 River Sediment, EPA 

Hazardous Soil and EPA Electroplating Sludge. Samples were prepared using the 

procedure described in Section 11.3. For each method element, the sample 

background concentration, mean percent recovery, the standard deviation of the 

percent recovery and the relative percent difference between the duplicate 

fortified samples were determined as for Section 13.2. 

13.4	 Data obtained from single laboratory testing of the method for drinking water 

analysis using the "direct analysis" procedure (Section 11.2.1) are given in 

Table 11. Three drinking water samples of varying hardness collected from 

Regions 4, 6, and 10 were fortified to contain 1 μg/L of all metal primary 

contaminants, except selenium, which was added to a concentration of 20 μg/L. 

For each matrix, four replicate aliquots were analyzed to determine the sample 

background concentration of each analyte and four fortified aliquots were 

analyzed to determine mean percent recovery in each matrix. Listed in the 

Table 11 are the average mean percent recovery of each analyte in the three 

matrices and the standard deviation of the mean percent recoveries. 

13.5	 Listed in Table 12 are the regression equations for precision and bias developed 

from the joint USEPA/Association of Official Analytical Chemists (AOAC) 

multilaboratory validation study conducted on this method. These equations 

200.8-29
 
were developed from data received from 13 laboratories on reagent water, 

drinking water and ground water. Listed in Tables 13 and 14, respectively, are 

the precision and recovery data from a wastewater digestate supplied to all 

laboratories and from a wastewater of the participant's choice. For a complete 

review of the study see Reference 11, Section 16.0 of this method. 

14.0	 POLLUTION PREVENTION 

14.1	 Pollution prevention encompasses any technique that reduces or eliminates the 

quantity or toxicity of waste at the point of generation. Numerous opportunities 

for pollution prevention exist in laboratory operation. The EPA has established 

a preferred hierarchy of environmental management techniques that places 

pollution prevention as the management option of first choice. Whenever 

feasible, laboratory personnel should use pollution prevention techniques to 

address their waste generation. When wastes cannot be feasibly reduced at the 

source, the Agency recommends recycling as the next best option. 

14.2	 For information about pollution prevention that may be applicable to laboratories 

and research institutions, consult “Less is Better: Laboratory Chemical 

Management for Waste Reduction”, available from the American Chemical 

Society's Department of Government Relations and Science Policy, 1155 16th 

Street N.W., Washington D.C. 20036, (202)872-4477. 

15.0	 WASTE MANAGEMENT 

15.1	 The Environmental Protection Agency requires that laboratory waste management 

practices be conducted consistent with all applicable rules and regulations. The 

Agency urges laboratories to protect the air, water, and land by minimizing and 

controlling all releases from hoods and bench operations, complying with the 

letter and spirit of any sewer discharge permits and regulations, and by 

complying with all solid and hazardous waste regulations, particularly the 

hazardous waste identification rules and land disposal restrictions. For further 

information on waste management consult “The Waste Management Manual for 

Laboratory Personnel”, available from the American Chemical Society at the 

address listed in the Section 14.2. 

16.0	 REFERENCES 

1.	 Gray, A.L. and A. R. Date. Inductively Coupled Plasma Source Mass 

Spectrometry Using Continuum Flow Ion Extraction. Analyst 108 1033-1050, 1983. 

2.	 Houk, R.S. et al. Inductively Coupled Argon Plasma as an Ion Source for Mass 

Spectrometric Determination of Trace Elements. Anal Chem. 52 2283-2289, 1980. 

3.	 Houk, R.S. Mass Spectrometry of Inductively Coupled Plasmas. Anal. Chem. 58 

97A-105A, 1986. 

4.	 Thompson, J.J. and R. S. Houk. A Study of Internal Standardization in 

Inductively Coupled Plasma-Mass Spectrometry. Appl. Spec. 41 801-806, 1987. 

200.8-30
 
5.	 Carcinogens - Working With Carcinogens, Department of Health, Education, and 

Welfare, Public Health Service, Center for Disease Control, National Institute for 

Occupational Safety and Health, Publication No. 77-206, Aug. 1977. Available 

from the National Technical Information Service (NTIS) as PB-277256. 

6.	 OSHA Safety and Health Standards, General Industry, (29 CFR 1910), 

Occupational Safety and Health Administration, OSHA 2206, (Revised, 

January 1976). 

7.	 Safety in Academic Chemistry Laboratories, American Chemical Society 

Publication, Committee on Chemical Safety, 3rd Edition, 1979. 

8.	 Proposed OSHA Safety and Health Standards, Laboratories, Occupational Safety 

and Health Administration, Federal Register, July 24, 1986. 

9.	 American Society for Testing and Materials. Standard Specification for Reagent 

Water, D1193-77. Annual Book of ASTM Standards, Vol. 11.01. Philadelphia, PA, 

1991. 

10.	 Code of Federal Regulations 40, Ch. 1, Pt. 136 Appendix B. 

11.	 Longbottom, J.E. et. al. Determination of Trace Elements in Water by Inductively 

Coupled Plasma-Mass Spectrometry: Collaborative Study, Journal of AOAC 

International 77 1004-1023, 1994. 

12.	 Hinners, T.A. Interferences in ICP-MS by Bromine Species. Winter Conference 

on Plasma Spectrochemistry, San Diego, CA, January, 10-15, 1994. 

200.8-31
 
17.0 TABLES, DIAGRAMS, FLOWCHARTS, AND VALIDATION DATA 

TABLE 1: ESTIMATED INSTRUMENT DETECTION LIMITS 

Element 

Recommended 

Analytical Mass 

Scanning 

Mode 1 

Selection Ion 

Monitoring Mode 2,3

Aluminum 27 0.05 0.02 

Antimony 123 0.08 0.008 

Arsenic (3) 75 0.9 0.02 

Barium 137 0.5 0.03 

Beryllium 9 0.1 0.02 

Cadmium 111 0.1 0.02 

Chromium 52 0.07 0.04 

Cobalt 59 0.03 0.002 

Copper 63 0.03 0.004 

Lead 206, 207, 208 0.08 0.015 

Manganese 55 0.1 0.007 

Mercury 202 n.a 0.2 

Molybdenum 98 0.1 0.005 

Nickel 60 0.2 0.07 

Selenium (3) 82 5 1.3 

Silver 107 0.05 0.004 

Thallium 205 0.09 0.014 

Thorium 232 0.03 0.005 

Uranium 238 0.02 0.005 

Vanadium 51 0.02 0.006 

Zinc 66 0.2 0.07 

Instrument detection limits (3a) estimated from seven replicate integrations of the 

blank (1% v/v nitric acid) following calibration of the instrument with three replicate 

integrations of a multi-element standard. 

1

Instrument operating conditions and data acquisition mode are given in Table 6. 

2 75 77 IDLs determined using state-of-the-art instrumentation (1994). Data for As, Se, 

and 82Se were acquired using a dwell time of 4.096 seconds with 1500 area count per 

sec 83Kr present in argon supply. All other data were acquired using a dwell time of 

1.024 seconds per AMU monitored. 

200.8-32
 
TABLE 2: COMMON MOLECULAR ION INTERFERENCES IN ICP-MS
 

BACKGROUND MOLECULAR IONS
 

Molecular Ion Mass Element Interferencea 

NH+ 

OH+ 

OH + 

2

C2

+ 

CN+ 

CO+ 

N2

+ 

N H+ 

2 

NO+ 

NOH+ 

O2

+ 

O H+ 

2 

36ArH+ 

38ArH+ 

40ArH+ 

CO + 

2

CO2H + 

ArC+, ArO +

ArN+ 

ArNH+ 

ArO+ 

ArOH+ 

40 Ar36 Ar +

40 Ar38 Ar +

40Ar+ 

15
 

17
 

18
 

24

26
 

28
 

28

29 
 

30
 

31
 

32

33 
 

37
 

39
 

41
 

44
 

45 

52 

54 

55 

56
 

57
 

76 

78 

80 

Sc
 

Cr
 

Cr
 

Mn
 

Se 

Se

Se 

a

method elements or internal standards affected by the molecular ions. 

200.8-33
 
TABLE 2: COMMON MOLECULAR ION INTERFERENCES IN ICP-MS (Cont’d) 

MATRIX MOLECULAR IONS
 

Molecular Ion Mass Element Interferencea 

Bromide12 

81BrH+ 

79BrO+ 

81BrO+ 

81BrOH+ 

Ar 81 Br +

Chloride 

35ClO+ 

35ClOH+ 

37ClO+ 

37ClOH+ 

Ar 35 Cl +

Ar 37 Cl +

Sulphate 

32SO+ 

32SOH+ 

34SO+ 

34SOH+ 

SO + + 

2 , S2

Ar 32 S +

Ar 34 S +

Phosphate 

PO+ 

POH+ 

PO + 

2

ArP+ 

Group I, II Metals 

ArNa+ 

ArK+ 

ArCa+ 

82 

95 

97 

98 

121 

51 

52 

53 

54 

75 

77 

48 

49 

50 

51 

64 

72 

74 

47 

48 

63 

71 

63 

79 

80 

Se
 

Mo
 

Mo
 

Mo
 

Sb 

V 

Cr 

Cr 

Cr 

As 

Se 

V, Cr 

V 

Zn 

Cu 

Cu 

200.8-34
 
TABLE 2: COMMON MOLECULAR ION INTERFERENCES IN ICP-MS (Cont’d) 

MATRIX MOLECULAR IONS
 

Molecular Ion Mass Element Interferencea 

Matrix Oxides* 

TiO 

ZrO 

MoO 

62-66 

106-112 

108-116 

Ni, Cu, Zn 

Ag, Cd 

Cd 

*

Oxide interferences will normally be very small and will only impact the method 

elements when present at relatively high concentrations. Some examples of matrix 

oxides are listed of which the analyst should be aware. It is recommended that Ti 

and Zr isotopes are monitored in solid waste samples, which are likely to contain 

high levels of these elements. Mo is monitored as a method analyte. 

200.8-35
 
TABLE 3: INTERNAL STANDARDS AND LIMITATIONS OF USE
 

Internal Standard Mass Possible Limitation 

6 Lithium 6 a 

Scandium 45 polyatomic ion interference 

Yttrium 89 a,b 

Rhodium 103 

Indium 115 isobaric interference by Sn 

Terbium 159 

Holmium 165 

Lutetium 175 

Bismuth 209 a 

a May be present in environmental samples. 

+ b In some instruments Yttrium may form measurable amounts of YO (105 amu)and

YOH+ (106 amu). If this is the case, care should be taken in the use of the cadmium 

elemental correction equation. 

Internal standards recommended for use with this method are shown in bold face. 

Preparation procedures for these are included in Section 7.3. 

200.8-36
 
TABLE 4: RECOMMENDED ANALYTICAL ISOTOPES AND ADDITIONAL
 

MASSES WHICH MUST BE MONITORED
 

Isotope Element of Interest 

27 Aluminum 

121, 123 

75 

Antimony 

Arsenic 

135, 137 

9 

106, 108, 111, 114 

52, 53 

59 

Barium 

Beryllium 

Cadmium 

Chromium 

Cobalt 

63, 65 

206, 207, 208 

55 

95, 97, 98 

60, 62 

77, 82 

107, 109 

203, 205 

232 

Copper 

Lead 

Manganese 

Molybdenum 

Nickel 

Selenium 

Silver 

Thallium 

Thorium 

238 Uranium 

51 Vanadium 

66, 67, 68 

83 

99 

105 

118 

Zinc 

Krypton 

Ruthenium 

Palladium 

Tin 

NOTE: Isotopes recommended for analytical determination are underlined. 

200.8-37
 
TABLE 5: RECOMMENDED ELEMENTAL EQUATIONS FOR DATA
 

CALCULATIONS
 

Element Elemental Equation Note 

Al (1.000) ( C) 27 

Sb (1.000) ( C) 123 

As (1.000) ( C)-(3.127) [( C)-(0.815) ( C)] 75 77 82 (1) 

Ba (1.000) ( C) 137 

Be (1.000) ( C) 9 

Cd (1.000) ( C)-(1.073) [( 111 108C)-(0.712) ( C)] 106 (2) 

Cr (1.000) ( C) 52 (3) 

Co (1.000) ( C) 59 

Cu (1.000) ( C) 63 

Pb (1.000) ( C)+(1.000) [( 206 207C)+(1.000) ( C)] 208 (4) 

Mn (1.000) ( C) 55 

Mo (1.000) ( C)-(0.146) ( C) 98 99 (5) 

Ni (1.000) ( C) 60 

Se (1.000) ( C) 82 (6) 

Ag (1.000) ( C) 107 

Tl (1.000) ( C) 205 

Th (1.000) ( C) 232 

U (1.000) ( C) 238 

V (1.000) ( C)-(3.127) [( C)-(0.113) ( C)] 51 53 52 (7) 

Zn (1.000) ( C) 66 

200.8-38
 
TABLE 5: RECOMMENDED ELEMENTAL EQUATIONS FOR DATA
 

CALCULATIONS
 

Element Elemental Equation Note 

Bi (1.000) ( C) 209 

In (1.000) ( C)-(0.016) ( C) 209 118 (8) 

Sc (1.000) ( C) 45 

Tb (1.000) ( C) 159 

Y (1.000) ( C) 89 

C - Calibration blank subtracted counts at specified mass. 

(1) - Correction for chloride interference with adjustment for 77Se. ArCl 75/77 ratio 

may be determined from the reagent blank. Isobaric mass 82 must be from Se only + and not BrH . 

(2) - Correction for MoO interference. Isobaric mass 106 must be from Cd only not 

+ ZrO . An additional isobaric elemental correction should be made if palladium is 

present. 

(3) - In 0.4% v/v HCl, the background from ClOH will normally be small. However 

the contribution may be estimated from the reagent blank. Isobaric mass must be + from Cr only not ArC .

(4) - Allowance for isotopic variability of lead isotopes. 

(5) - Isobaric elemental correction for ruthenium. 

(6) - Some argon supplies contain krypton as an impurity. Selenium is corrected for 

82Kr by background subtraction. 

(7) - Correction for chloride interference with adjustment for 53Cr. ClO 51/53 ratio 

may be determined from the reagent blank. Isobaric mass 52 must be from Cr only 

not ArC +

.

(8) - Isobaric elemental correction for tin. 

200.8-39
 
TABLE 6: INSTRUMENT OPERATING CONDITIONS FOR PRECISION
 

AND RECOVERY DATA1
 

Instrument VG PlasmaQuad Type I 

Plasma foward power 1.35 kW 

Coolant flow rate 13.5 L/min. 

Auxillary flow rate 0.6 L/min. 

Nebulizer flow rate 0.78 L/min. 

Solution uptake rate 0.6 mL/min. 

Spray chamber temperature 15°C 

Data Acquistion 

Detector mode Pulse counting 

Replicate integrations 3 

Mass range 8-240 amu 

Dwell time 320 μs 

Number of MCA channels 2048 

Number of scan sweeps 85 

Total acquisition time 3 minutes per sample 

1

The described instrument and operating conditions were used to determine the 

scanning mode MDL data listed in Table 7 and the precision and recovery data given 

in Tables 9 and 10. 

200.8-40
 
TABLE 7: METHOD DETECTION LIMITS
 

AMUElement 

Scanning Mode1 

Total Recoverable 

Aqueous 

μg/L 

Solids 

mg/kg 

Selection Ion Monitoring Mode2 

Total Recoverable 

Aqueous 

μg/L 

 Direct Analysis3 

Aqueous

μg/L 

27 Al 

123 Sb 

75 As 

137 Ba 

9 Be 

111 Cd 

52 Cr 

59 Co 

63 Cu 

206,207,208 Pb 

55 Mn 

202 Hg 

98 Mo 

60 Ni 

82 Se 

107 Ag 

205 Tl 

232 Th 

238 U 

51 V 

66 Zn 

1.0 

0.4 

1.4 

0.8 

0.3 

0.5 

0.9 

0.09 

0.5 

0.6 

0.1 

n.a. 

0.3 

0.5 

7.9 

0.1 

0.3 

0.1 

0.1 

2.5 

1.8 

0.4 

0.2 

0.6 

0.4 

0.1 

0.2 

0.4 

0.04 

0.2 

0.3 

0.05 

n.a. 

0.1 

0.2 

3.2 

0.05 

0.1 

0.05 

0.05 

1.0 

0.7 

1.7 

0.04 

0.4 

0.04 

0.02 

0.03 

0.08 

0.004 

0.02 

0.05 

0.02 

n.a 

0.01 

0.06 

2.1 

0.005 

0.02 

0.02 

0.01 

0.9 

0.1 

0.04 

0.02 

0.1 

0.04 

0.03 

0.03 

0.08 

0.003 

0.01 

0.02 

0.04 

0.2 

0.01 

0.03 

0.5 

0.005 

0.01 

0.01 

0.01 

0.05 

0.2 

1

Data acquisition mode given in Table 6. Total recoverable MDL concentrations are 

computed for original matrix with allowance for sample dilution during preparation. 

Listed MDLs for solids calculated from determined aqueous MDLs. 

2 MDLs determined using state-of-the-art instrumentation (1994). Data for As, Se, 75 77

and 82Se were acquired using a dwell time of 4.096 seconds with 1500 area count per 

seconds 83Kr present in argon supply. All other data were acquired using a dwell 

time of 1.024 seconds per AMU monitored. 

3

MDLs were determined from analysis of seven undigested aqueous sample aliquots. 

n.a. - Not applicable. Total recoverable digestion not suitable for organo-mercury 

compounds. 

200.8-41
 
TABLE 8: ACCEPTANCE LIMITS FOR QC CHECK SAMPLE
 

METHOD PERFORMANCE (μg/L)1
 

QC Check 

Sample 

Conc. 

Standard 

Deviation2 

(S r ) 

Acceptance 

Limits3 

μg/L 

Average 

Element Recovery 

Aluminum 100 100.4 5.49 84-117 

Antimony 100 99.9 2.40 93-107 

Arsenic 100 101.6 3.66 91-113 

Barium 100 99.7 2.64 92-108 

Beryllium 100 105.9 4.13 88-1124 

Cadmium 100 100.8 2.32 94-108 

Chromium 100 102.3 3.91 91-114 

Cobalt 100 97.7 2.66 90-106 

Copper 100 100.3 2.11 94-107 

Lead 100 104.0 3.42 94-114 

Manganese 100 98.3 2.71 90-106 

Molybdenum 100 101.0 2.21 94-108 

Nickel 100 100.1 2.10 94-106 

Selenium 100 103.5 5.67 86-121 

Silver 100 101.1 3.29 91-1115 

Thallium 100 98.5 2.79 90-107 

Thorium 100 101.4 2.60 94-109 

Uranium 100 102.6 2.82 94-111 

Vanadium 100 100.3 3.26 90-110 

Zinc 100 105.1 4.57 91-119 

1

Method performance characteristics calculated using regression equations from
 

collaborative study, Reference 11.
 

2

Single-analyst standard deviation, S .r
 

3

Acceptance limits calculated as average recovery ± three standard deviations.
 

4

Acceptance limits centered at 100% recovery.
 

5

Statistics estimated from summary statistics at 48 and 64 μg/L.
 

200.8-42
 
TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES
 

DRINKING WATER
 

Sample 

Conc. 

μg/L 

Low 

Spike 

μg/L 

Average 

Recovery 

R (%) 

High 

Spike 

μg/L 

Average 

Recovery 

Element S (R) RPD R (%) S (R) RPD 

Al 175 50 115.8 5.9 0.4 200 102.7 1.6 1.1 

Sb <0.4 10 99.1 0.7 2.0 100 100.8 0.7 2.0 

As <1.4 50 99.7 0.8 2.2 200 102.5 1.1 2.9 

Ba 43.8 50 94.8 3.9 5.8 200 95.6 0.8 1.7 

Be <0.3 10 113.5 0.4 0.9 100 111.0 0.7 1.8 

Cd <0.5 10 97.0 2.8 8.3 100 101.5 0.4 1.0 

Cr <0.9 10 111.0 3.5 9.0 100 99.5 0.1 0.2 

Co 0.11 10 94.4 0.4 1.1 100 93.6 0.5 1.4 

Cu 3.6 10 101.8 8.8 17.4 100 91.6 0.3 0.3 

Pb 0.87 10 97.8 2.0 2.8 100 99.0 0.8 2.2 

Mn 0.96 10 96.9 1.8 4.7 100 95.8 0.6 1.8 

Mo 1.9 10 99.4 1.6 3.4 100 98.6 0.4 1.0 

Ni 1.9 10 100.2 5.7 13.5 100 95.2 0.5 1.3 

Se <7.9 50 99.0 1.8 5.3 200 93.5 3.5 10.7 

Ag <0.1 50 100.7 1.5 4.2 200 99.0 0.4 1.0 

Tl <0.3 10 97.5 0.4 1.0 100 98.5 1.7 4.9 

Th <0.1 10 109.0 0.7 1.8 100 106.0 1.4 3.8 

U 0.23 10 110.7 1.4 3.5 100 107.8 0.7 1.9 

V <2.5 50 101.4 0.1 0.4 200 97.5 0.7 2.1 

Zn 5.2 50 103.4 3.3 7.7 200 96.4 0.5 1.0 

S (R) Standard deviation of percent recovery.
 

RPD Relative percent difference between duplicate spike determinations.
 

< Sample concentration below established method detection limit.
 

200.8-43
 
TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS
 

MATRICES (Cont’d)
 

WELL WATER
 

Sample Low Average High Average 

Conc. Spike Recovery Spike Recovery 

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD 

Al 34.3 50 100.1 3.9 0.8 200 102.6 1.1 1.3 

Sb 0.46 10 98.4 0.9 1.9 100 102.5 0.7 1.9 

As <1.4 50 110.0 6.4 16.4 200 101.3 0.2 0.5 

Ba 106 50 95.4 3.9 3.3 200 104.9 1.0 1.6 

Be <0.3 10 104.5 0.4 1.0 100 101.4 1.2 3.3 

Cd 106 10 88.6 1.7 3.8 100 98.6 0.6 1.6 

Cr <0.9 10 111.0 0.0 0.0 100 103.5 0.4 1.0 

Co 2.4 10 100.6 1.0 1.6 100 104.1 0.4 0.9 

Cu 37.4 10 104.3 5.1 1.5 100 100.6 0.8 1.5 

Pb 3.5 10 95.2 2.5 1.5 100 99.5 1.4 3.9 

Mn 2770 10 * * 1.8 100 * * 0.7 

Mo 2.1 10 103.8 1.1 1.6 100 102.9 0.7 1.9 

Ni 11.4 10 116.5 6.3 6.5 100 99.6 0.3 0.0 

Se <7.9 50 127.3 8.4 18.7 200 101.3 0.2 0.5 

Ag <0.1 50 99.2 0.4 1.0 200 101.5 1.4 3.9 

Tl <0.3 10 93.9 0.1 0.0 100 100.4 1.8 5.0 

Th <0.1 10 103.0 0.7 1.9 100 104.5 1.8 4.8 

U 1.8 10 106.0 1.1 1.6 100 109.7 2.5 6.3 

V <2.5 50 105.3 0.8 2.1 200 105.8 0.2 0.5 

Zn 554 50
 * * 1.2
 200
 102.1 5.5 3.2
 

S (R) Standard deviation of percent recovery.
 

RPD Relative percent difference between duplicate spike determinations.
 

< Sample concentration below established method detection limit.
 

* Spike concentration <10% of sample background concentration. 

200.8-44
 
TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS
 

MATRICES (Cont’d)
 

POND WATER
 

Sample Low Average High Average 

Conc. Spike Recovery Spike Recovery 

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD 

Al 610 50 * * 1.7 200 78.2 9.2 5.5 

Sb <0.4 10 101.1 1.1 2.9 100 101.5 3.0 8.4 

As <1.4 50 100.8 2.0 5.6 200 96.8 0.9 2.6 

Ba 28.7 50 102.1 1.8 2.4 200 102.9 3.7 9.0 

Be <0.3 10 109.1 0.4 0.9 100 114.4 3.9 9.6 

Cd <0.5 10 106.6 3.2 8.3 100 105.8 2.8 7.6 

Cr 2.0 10 107.0 1.0 1.6 100 100.0 1.4 3.9 

Co 0.79 10 101.6 1.1 2.7 100 101.7 1.8 4.9 

Cu 5.4 10 107.5 1.4 1.9 100 98.1 2.5 6.8 

Pb 1.9 10 108.4 1.5 3.2 100 106.1 0.0 0.0 

Mn 617 10 * * 1.1 100 139.0 11.1 4.0 

Mo 0.98 10 104.2 1.4 3.5 100 104.0 2.1 5.7 

Ni 2.5 10 102.0 2.3 4.7 100 102.5 2.1 5.7 

Se <7.9 50 102.7 5.6 15.4 200 105.5 1.4 3.8 

Ag 0.12 50 102.5 0.8 2.1 200 105.2 2.7 7.1 

Tl <0.3 10 108.5 3.2 8.3 100 105.0 2.8 7.6 

Th 0.19 10 93.1 3.5 10.5 100 93.9 1.6 4.8 

U 0.30 10 107.0 2.8 7.3 100 107.2 1.8 4.7 

V 3.5 50 96.1 5.2 14.2 200 101.5 0.2 0.5 

Zn 6.8 50 99.8 1.7 3.7 200 100.1 2.8 7.7 

S (R) Standard deviation of percent recovery.
 

RPD Relative percent difference between duplicate spike determinations.
 

< Sample concentration below established method detection limit.
 

* Spike concentration <10% of sample background concentration. 

200.8-45
 
TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS
 

MATRICES (Cont’d)
 

SEWAGE TREATMENT PRIMARY EFFLUENT
 

Sample Low Average High Average 

Conc. Spike Recovery Spike Recovery 

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD 

Al 1150 50 * * 3.5 200 100.0 13.8 1.5 

Sb 1.5 10 95.7 0.4 0.9 100 104.5 0.7 1.9 

As <1.4 50 104.2 4.5 12.3 200 101.5 0.7 2.0 

Ba 202 50 79.2 9.9 2.5 200 108.6 4.6 5.5 

Be <0.3 10 110.5 1.8 4.5 100 106.4 0.4 0.9 

Cd 9.2 10 101.2 1.3 0.0 100 102.3 0.4 0.9 

Cr 128 10 * * 1.5 100 102.1 1.7 0.4 

Co 13.4 10 95.1 2.7 2.2 100 99.1 1.1 2.7 

Cu 171 10 * * 2.4 100 105.2 7.1 0.7 

Pb 17.8 10 95.7 3.8 1.1 100 102.7 1.1 2.5 

Mn 199 10 * * 1.5 100 103.4 2.1 0.7 

Mo 136 10 * * 1.4 100 105.7 2.4 2.1 

Ni 84.0 10 88.4 16.3 4.1 100 98.0 0.9 0.0 

Se <7.9 50 112.0 10.9 27.5 200 108.8 3.0 7.8 

Ag 10.9 50 97.1 0.7 1.5 200 102.6 1.4 3.7 

Tl <0.3 10 97.5 0.4 1.0 100 102.0 0.0 0.0 

Th 0.11 10 15.4 1.8 30.3 100 29.3 0.8 8.2 

U 0.71 10 109.4 1.8 4.3 100 109.3 0.7 1.8 

V <2.5 50 90.9 0.9 0.6 200 99.4 2.1 6.0 

Zn 163 50 85.8 3.3 0.5 200 102.0 1.5 1.9 

S (R) Standard deviation of percent recovery.
 

RPD Relative percent difference between duplicate spike determinations.
 

< Sample concentration below established method detection limit.
 

* Spike concentration <10% of sample background concentration. 

200.8-46
 
TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS
 

MATRICES (Cont’d)
 

INDUSTRIAL EFFLUENT
 

Sample Low Average High Average 

Conc. Spike Recovery Spike Recovery 

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD 

Al 44.7 50 98.8 8.7 5.7 200 90.4 2.1 2.2 

Sb 2990 10 * * 0.3 100 * * 0.0 

As <1.4 50 75.1 1.8 6.7 200 75.0 0.0 0.0 

Ba 100 50 96.7 5.5 3.4 200 102.9 1.1 0.7 

Be <0.3 10 103.5 1.8 4.8 100 100.0 0.0 0.0 

Cd 10.1 10 106.5 4.4 2.4 100 97.4 1.1 2.8 

Cr 171 10 * * 0.0 100 127.7 2.4 1.7 

Co 1.3 10 90.5 3.2 8.7 100 90.5 0.4 1.3 

Cu 101 10 * * 0.9 100 92.5 2.0 1.6 

Pb 294 10 * * 2.6 100 108.4 2.1 0.0 

Mn 154 10 * * 2.8 100 103.6 3.7 1.6 

Mo 1370 10 * * 1.4 100 * * 0.7 

Ni 17.3 10 107.4 7.4 5.0 100 88.2 0.7 1.0 

Se 15.0 50 129.5 9.3 15.1 200 118.3 1.9 3.6 

Ag <0.1 50 91.8 0.6 1.7 200 87.0 4.9 16.1 

Tl <0.3 10 90.5 1.8 5.5 100 98.3 1.0 2.8 

Th 0.29 10 109.6 1.2 2.7 100 108.7 0.0 0.0 

U 0.17 10 104.8 2.5 6.6 100 109.3 0.4 0.9 

V <2.5 50 74.9 0.1 0.3 200 72.0 0.0 0.0 

Zn 43.4 50 85.0 4.0 0.6 200 97.6 1.0 0.4 

S (R) Standard deviation of percent recovery.
 

RPD Relative percent difference between duplicate spike determinations.
 

< Sample concentration below established method detection limit.
 

* Spike concentration <10% of sample background concentration. 

200.8-47
 
TABLE 10: PRECISION AND RECOVERY DATA IN SOLID MATRICES
 

EPA HAZARDOUS SOIL #884
 

Sample Low+ Average High+ Average 

Conc. Spike Recovery Spike Recovery 

Element (mg/kg) (mg/kg) R (%) S (R) RPD (mg/kg) R (%) S (R) RPD 

Al 5170 20 * * – 100 * * – 

Sb 5.4 20 69.8 2.5 4.7 100 70.4 1.8 6.5 

As 8.8 20 104.7 5.4 9.1 100 102.2 2.2 5.4 

Ba 113 20 54.9 63.6 18.6 100 91.0 9.8 0.5 

Be 0.6 20 100.1 0.6 1.5 100 102.9 0.4 1.0 

Cd 1.8 20 97.3 1.0 1.4 100 101.7 0.4 1.0 

Cr 83.5 20 86.7 16.1 8.3 100 105.5 1.3 0.0 

Co 7.1 20 98.8 1.2 1.9 100 102.9 0.7 1.8 

Cu 115 20 86.3 13.8 3.4 100 151.7 4.2 4.6 

Pb 152 20 85.0 45.0 13.9 100 85.2 25.7 23.7 

Mn 370 20 * * 12.7 100 95.2 10.4 2.2 

Mo 4.8 20 95.4 1.5 2.9 100 102.3 0.7 2.0 

Ni 19.2 20 101.7 3.8 1.0 100 100.7 0.8 0.8 

Se <3.2 20 79.5 7.4 26.4 100 94.8 9.4 26.5 

Ag 1.1 20 96.1 0.6 0.5 100 97.9 0.8 2.3 

Tl 0.24 20 94.3 1.1 3.1 100 76.0 1.0 2.9 

Th 1.0 20 69.8 0.6 1.3 100 102.9 2.2 7.9 

U 1.1 20 100.1 0.2 0.0 100 106.7 0.0 0.0 

V 17.8 20 109.2 4.2 2.3 100 113.4 1.3 2.4 

Zn 128 20 87.0 27.7 5.5 100 12.9 14.1 

S (R) Standard deviation of percent recovery.
 

RPD Relative percent difference between duplicate spike determinations.
 

< Sample concentration below established method detection limit.
 

* Spike concentration <10% of sample background concentration. 

– Not determined.

+ Equivalent. 

200.8-48
 
Sample Low+ Average High+ Average 

Conc. Spike Recovery Spike Recovery 

Element (mg/kg) (mg/kg) R (%) S (R) RPD (mg/kg) R (%) S (R) RPD 

Al 5060 20 * * – 100 * * – 

Sb 21.8 20 73.9 6.5 9.3 100 81.2 1.5 3.9 

As 67.2 20 104.3 13.0 7.6 100 107.3 2.1 2.9 

Ba 54.4 20 105.6 4.9 2.8 100 98.6 2.2 3.9 

Be 0.59 20 88.8 0.2 0.5 100 87.9 0.1 0.2 

Cd 8.3 20 92.9 0.4 0.0 100 95.7 1.4 3.9 

Cr 29100 20 * * – 100 * * – 

Co 7.9 20 97.6 1.3 2.6 100 103.1 0.0 0.0 

Cu 112 20 121.0 9.1 1.5 100 105.2 2.2 1.8 

Pb 742 20 * * – 100 – – – 

Mn 717 20 * * – 100 – – – 

Mo 17.1 20 89.8 8.1 12.0 100 98.4 0.7 0.9 

Ni 41.8 20 103.7 6.5 4.8 100 102.2 0.8 0.0 

Se <3.2 20 108.3 14.3 37.4 100 93.9 5.0 15.1 

Ag 1.8 20 94.8 1.6 4.3 100 96.2 0.7 1.9 

Tl 1.2 20 91.2 1.3 3.6 100 94.4 0.4 1.3 

Th 0.90 20 91.3 0.9 2.6 100 92.3 0.9 2.8 

U 0.79 20 95.6 1.8 5.0 100 98.5 1.2 3.5 

V 21.8 20 91.8 4.6 5.7 100 100.7 0.6 0.8 

Zn 1780 20 * * – 100 * * – 

TABLE 10: PRECISION AND RECOVERY DATA IN SOLID MATRICES
 

NBS 1645 RIVER SEDIMENT
 

S (R) Standard deviation of percent recovery.
 

RPD Relative percent difference between duplicate spike determinations.
 

< Sample concentration below established method detection limit.
 

* Spike concentration <10% of sample background concentration. 

– Not determined.

+ Equivalent. 

200.8-49
 
Sample 

Conc. 

(mg/kg) 

Low+ 

Spike 

mg/kg) 

Average 

Recovery 

R (%) 

High+ 

Spike 

(mg/kg)

Average 

Recovery 

Element ( S (R) RPD R (%) S (R) RPD 

Al 5110 20 * * – 100 * * – 

Sb 8.4 20 55.4 1.5 4.1 100 61.0 0.2 0.9 

As 41.8 20 91.0 2.3 1.7 100 94.2 0.8 1.5 

Ba 27.3 20 1.8 7.1 8.3 100 0 1.5 10.0 

Be 0.25 20 92.0 0.9 2.7 100 93.4 0.3 0.9 

Cd 112 20 85.0 5.2 1.6 100 88.5 0.8 0.5 

Cr 7980 20 * * – 100 * * – 

Co 4.1 20 89.2 1.8 4.6 100 88.7 1.5 4.6 

Cu 740 20 * * 6.0 100 61.7 20.4 5.4 

Pb 1480 20 * * – 100 * * – 

Mn 295 20 * * – 100 – – – 

Mo 13.3 20 82.9 1.2 1.3 100 89.2 0.4 1.0 

Ni 450 20 * * 6.8 100 83.0 10.0 4.5 

Se 3.5 20 89.7 3.7 4.2 100 91.0 6.0 18.0 

Ag 5.9 20 89.8 2.1 4.6 100 85.1 0.4 1.1 

Tl 1.9 20 96.9 0.9 2.4 100 98.9 0.9 2.4 

Th 3.6 20 91.5 1.3 3.2 100 97.4 0.7 2.0 

U 2.4 20 107.7 2.0 4.6 100 109.6 0.7 1.8 

V 21.1 20 105.6 1.8 2.1 100 97.4 1.1 2.5 

Zn 13300 20 * * – 100 * * – 

TABLE 10: PRECISION AND RECOVERY DATA IN SOLID MATRICES
 

EPA ELECTROPLATING SLUDGE #286
 

S (R) Standard deviation of percent recovery.
 

RPD Relative percent difference between duplicate spike determinations.
 

< Sample concentration below established method detection limit.
 

* Spike concentration <10% of sample background concentration. 

– Not determined.

+ Equivalent. 

200.8-50
 
TABLE 11: PRIMARY DRINKING WATER CONTAMINANTS
 

PRECISION AND RECOVERY DATA
 

Regional Sample 

Background Concentration, μg/L Average Mean1 

Analyte (IV) (VI) (X) % Recovery S (R) 

Antimony 0.16 0.07 0.03 114% 1.9 

Arsenic < MDL 2.4 1.0 93 8.5 

Barium 4.6 280 14.3 (*) – 

Beryllium < MDL < MDL < MDL 100% 8.2 

Cadmium 0.05 0.05 0.03 81 4.0 

Chromium 0.71 5.1 0.10 94 2.5 

Copper 208 130 14.3 (*) – 

Lead 1.2 1.2 2.5 91 2.6 

Mercury < MDL 0.23 < MDL 86 11.4 

Nickel 1.7 3.6 0.52 101% 11.5 

Selenium < MDL 4.3 < MDL 98 8.4 

Thallium < MDL 0.01 < MDL 100 1.4 

1

The three regional waters were fortified with 1.0 μg/L of all analytes listed, except 

selenium, which was fortified to 20 μg/L. 

(*) Recovery of barium and copper was not calculated because the analyte addition 

was <20% the sample background concentration in all waters. (Recovery calculations 

are not required if the concentration of the analyte added is less than 30% of the 

sample background concentration. Section 9.4.3). 

S (R) Standard deviation of the mean percent recoveries. 

200.8-51
 



200.8-55
200.8-56

TABLE 13: BACKGROUND AND SPIKE MEASUREMENTS IN WAST

DIGESTATEa

Background

Concentrate 1 Concentrate 2

Std

Dev

μg/L

Std

Dev

μg/L

Std

Dev

μg/L

Conc.

μg/L

Spike

μg/L

Found

μg/L

% Rec

%

RSD

%

Spike

μg/L

Found

μg/L

% Rec

%

R

Be 0.0 0.0 100 94.5 11.8 94.5 12.5 125 118.1 14.7 94.5 

Al 78.2 12.4 200 260.9 41.2 91.4 15.8 250 309.1 48.5 92.4 Cr 19.5 8.1 200 222.2 23.3 101.4 10.5 250 274.3 26.6 101.9 V 1.9 2.8 250 271.8 36.5 108.0 13.4 200 219.3 30.1 108.7 Mn 296.6 24.7 125 419.0 35.7 97.9 8.5 100 397.4 34.8 100.8 Co 2.5 0.4 125 124.7 12.3 97.8 9.9 101 100.7 9.4 97.2 Ni 47.3 5.0 125 161.7 4.9 91.5 3.0 100 142.7 5.6 95.4 cu 77.4 13.2 125 194.5 29.5 93.7 15.2 100 172.3 26.6 94.9 Zn 77.4 4.9 200 257.4 16.3 90.0 6.3 250 302.5 21.1 90.0 As 0.8 1.1 200 194.9 8.0 97.1 4.1 250 244.7 12.8 97.6 Se 4.5 6.2 250 236.8 14.2 92.9 6.0 200 194.3 9.3 94.9 Mo 166.1 9.4 100 269.8 19.0 103.7 7.0 125 302.0 18.0 108.7 Ag Cd 0.6 0.7 2.7 1.1 200 125 176.0 14.6 87.7 117.0 4.8 91.4 8.3 4.1 250 100 214.6 17.8 85.6 96.6 3.2 93.9 Sb 3.3 0.2 100 100.2 4.8 96.9 4.8 125 125.9 4.3 98.1 

Ba 68.6 3.3 250 321.0 19.4 101.0 6.0 200 279.3 17.2 105.4 Tl 0.1 0.1 100 103.3 8.0 103.2 7.7 125 129.2 8.9 103.3 Pb 6.9 0.5 125 135.1 7.8 102.6 5.8 100 110.3 6.3 103.4 Th 0.1 0.1 125 140.2 19.5 112.1 13.9 100 113.3 15.4 113.2 U 0.4 0.2 125 141.2 19.3 112.6 13.7 100 113.6 16.0 113.2 

aResults from 10 participating laboratories. Wastewater digestate supplied with the materials. Mean background concentrations determined by the participants.
200.8-57

TABLE 14: SPIKE MEASUREMENTS IN PARTICIPANTS WASTEW

Concentrate 1 Concentrate 2

Std

Dev

μg/L

% Rec

% RS

%

Be

Spike

μg/L

Std

Dev

μg/L

Found

μg/L

% Rec

%

RSD

%

Spike

μg/L

Found

μg/L

101 103.4 12.0 103.4 11.6 125 128.2 13.6 102.6 1

Al 200 198.7 23.9 99.4 12.0 250 252.4 15.5 101.0 Cr 200 205.4 12.3 102.7 6.0 250 253.4 15.4 101.4 V 250 246.5 4.4 98.6 1.8 200 196.8 2.8 98.4 Mn 125 119.0 5.4 95.2 4.5 100 95.5 4.3 95.5 Co 125 125.8 7.0 100.6 5.6 101 99.5 5.3 98.5 Ni 125 127.4 9.7 101.9 7.6 100 101.0 7.5 101.0 cu 125 126.8 5.3 101.4 4.2 100 105.3 3.6 105.3 Zn 200 201.4 36.7 100.7 18.2 250 246.4 29.7 98.6 1As 200 207.3 11.9 103.7 5.7 250 263.0 2.6 105.2 Se 250 256.8 26.4 102.7 10.3 200 214.0 18.7 107.3 Mo 100 98.6 4.6 98.6 4.7 125 123.2 6.7 98.6 Ag 200 200.7 48.9 100.4 24.4 250 231.2 63.5 92.5 2Cd 125 123.2 11.5 98.6 9.3 100 95.8 2.9 95.8 Sb 100 92.2 4.4 92.2 4.8 125 119.0 1.0 95.2 Ba 250 245.2 12.8 98.1 5.2 200 204.7 12.1 102.4 Tl 100 100.0 0.9 100.0 0.9 125 128.0 6.0 102.4 Pb 125 125.8 5.1 100.6 4.1 100 100.8 2.7 100.8 Th 125 124.2 7.6 99.4 6.1 100 99.8 5.7 99.8 U 125 130.4 10.3 104.3 7.9 100 106.4 6.8 106.4 

aResults from five participating laboratories. Mean concentrations before spiking alisted because they varied considerably among the different wastewaters.