200.8-1

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
200.8-2

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:

Analyte Registry Number (CASRN)

Chemical Abstract Services

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.
200.8-3

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
200.8-4

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. Sample material in solution is introduced by pneumatic nebulization into 1-3

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).
200.8-5

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
200.8-6

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
200.8-7

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

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

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 Kr interference that affects the 82

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 recommended to reduce such effects. Internal 3

standardization may be effectively used to compensate for many physical

interference effects. Internal standards ideally should have similar 4
200.8-8

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

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
200.8-9

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.
200.8-10

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. 
200.8-11

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). Suitable water may be prepared by passing 9

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. 
200.8-12

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 O in a 2 3

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 BaCO in a 3

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 2 C4H 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 O in 2 3

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 CrO in 3

a solution mixture of 10 mL reagent grade water and 1 mL conc. nitric
200.8-13

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 HNO and dilute to 100 mL with reagent water. 3

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
200.8-14

100 mL with reagent grade water.

7.3.20 Selenium solution, stock 1 mL = 1000 μg Se: Dissolve 0.1405 g SeO in 2

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 O in 4 7

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 TlNO in 3

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 2 C4H 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

UO (NO ) 2 32 2 C6H O (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:
200.8-15

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. 
200.8-16

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
200.8-17

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)
200.8-18

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. To determine MDL values, take seven 7

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:
200.8-19

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: 
200.8-20

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 
200.8-21

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

C = fortified sample concentration s

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
200.8-22

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
200.8-23

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. 
200.8-24

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
200.8-25

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. Cover 3

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
200.8-26

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).
200.8-27

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.
200.8-28

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:

DW = Sample weight (g) dried at 60 Co

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.
200.8-29

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
200.8-30

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.
200.8-31

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. 
200.8-32

17.0 TABLES, DIAGRAMS, FLOWCHARTS, AND VALIDATION DATA

TABLE 1: ESTIMATED INSTRUMENT DETECTION LIMITS

Element Analytical Mass Mode Monitoring Mode

Recommended Scanning Selection Ion

1 2,3

Aluminum 27 0.05 0.02

Antimony 123 0.08 0.008

Arsenic 75 0.9 0.02 (3)

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 82 5 1.3 (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 (3F) 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.

Instrument operating conditions and data acquisition mode are given in Table 6. 1

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

and Se were acquired using a dwell time of 4.096 seconds with 1500 area count per 82

sec Kr present in argon supply. All other data were acquired using a dwell time of 83

1.024 seconds per AMU monitored.
200.8-33

TABLE 2: COMMON MOLECULAR ION INTERFERENCES IN ICP-MS

BACKGROUND MOLECULAR IONS

Molecular Ion Mass Element Interferencea

NH 15 +

OH 17 +

OH 18 2

+

C 24 2

+

CN 26 +

CO 28 +

N 28 2

+

N H 29 2

+

NO 30 +

NOH 31 +

O 32 2

+

O H 33 2

+

ArH 37 36 +

ArH 39 38 +

ArH 41 40 +

CO 44 2

+

CO H 45 Sc 2

+

ArC , ArO 52 Cr + +

ArN 54 Cr +

ArNH 55 Mn +

ArO 56 +

ArOH 57 +

Ar Ar 76 Se 40 36 +

Ar Ar 78 Se 40 38 +

Ar 80 Se 40 +

method elements or internal standards affected by the molecular ions. a
200.8-34

TABLE 2: COMMON MOLECULAR ION INTERFERENCES IN ICP-MS (Cont’d)

MATRIX MOLECULAR IONS

Molecular Ion Mass Element Interferencea

Bromide12

BrH 82 Se 81 +

BrO 95 Mo 79 +

BrO 97 Mo 81 +

BrOH 98 Mo 81 +

Ar Br 121 Sb 81 +

Chloride

ClO 51 V 35 +

ClOH 52 Cr 35 +

ClO 53 Cr 37 +

ClOH 54 Cr 37 +

Ar Cl 75 As 35 +

Ar Cl 77 Se 37 +

Sulphate

SO 48 32 +

SOH 49 32 +

SO 50 V, Cr 34 +

SOH 51 V 34 +

SO , S 64 Zn 2 2

+ +

Ar S 72 32 +

Ar S 74 34 +

Phosphate

PO 47 +

POH 48 +

PO 63 Cu 2

+

ArP 71 +

Group I, II Metals

ArNa 63 Cu +

ArK 79 +

ArCa 80 +
TABLE 2: COMMON MOLECULAR ION INTERFERENCES IN ICP-MS (Cont’d)

MATRIX MOLECULAR IONS

Molecular Ion Mass Element Interferencea

200.8-35

Matrix Oxides*

TiO 62-66 Ni, Cu, Zn

ZrO 106-112 Ag, Cd

MoO 108-116 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.
200.8-36

TABLE 3: INTERNAL STANDARDS AND LIMITATIONS OF USE

Internal Standard Mass Possible Limitation

Lithium 6 a 6

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.
200.8-37

TABLE 4: RECOMMENDED ANALYTICAL ISOTOPES AND ADDITIONAL

MASSES WHICH MUST BE MONITORED

Isotope Element of Interest

27 Aluminum

121, 123 Antimony

75 Arsenic

135, 137 Barium

9 Beryllium

106, 108, 111, 114 Cadmium

52, 53 Chromium

59 Cobalt

63, 65 Copper

206, 207, 208 Lead

55 Manganese

95, 97, 98 Molybdenum

60, 62 Nickel

77, 82 Selenium

107, 109 Silver

203, 205 Thallium

232 Thorium

238 Uranium

51 Vanadium

66, 67, 68 Zinc

83 Krypton

99 Ruthenium

105 Palladium

118 Tin

NOTE: Isotopes recommended for analytical determination are underlined.
200.8-38

TABLE 5: RECOMMENDED ELEMENTAL EQUATIONS FOR DATA

CALCULATIONS

Element Elemental Equation Note

Al (1.000) ( C)

Sb (1.000) ( C)

As (1.000) ( C)-(3.127) [( C)-(0.815) ( C)] (1)

Ba (1.000) ( C)

Be (1.000) ( C)

Cd (1.000) ( C)-(1.073) [( C)-(0.712) ( C)] (2)

Cr (1.000) ( C) (3)

Co (1.000) ( C)

Cu (1.000) ( C)

Pb (1.000) ( C)+(1.000) [( C)+(1.000) ( C)] (4)

Mn (1.000) ( C)

Mo (1.000) ( C)-(0.146) ( C) (5)

Ni (1.000) ( C)

Se (1.000) ( C) (6)

Ag (1.000) ( C)

Tl (1.000) ( C)

Th (1.000) ( C)

U (1.000) ( C)

V (1.000) ( C)-(3.127) [( C)-(0.113) ( C)] (7)

Zn (1.000) ( C)

27

123

75 77 82

137

9

111 108 106

52

59

63

206 207 208

55

98 99

60

82

107

205

232

238

51 53 52

66
TABLE 5: RECOMMENDED ELEMENTAL EQUATIONS FOR DATA

CALCULATIONS

Element Elemental Equation Note

200.8-39

Bi (1.000) ( C)

In (1.000) ( C)-(0.016) ( C) (8)

Sc (1.000) ( C)

Tb (1.000) ( C)

Y (1.000) ( C)

209

209 118

45

159

89

C - Calibration blank subtracted counts at specified mass.

(1) - Correction for chloride interference with adjustment for Se. ArCl 75/77 ratio 77

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

Kr by background subtraction. 82

(7) - Correction for chloride interference with adjustment for Cr. ClO 51/53 ratio 53

may be determined from the reagent blank. Isobaric mass 52 must be from Cr only

not ArC . +

(8) - Isobaric elemental correction for tin.
200.8-40

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

The described instrument and operating conditions were used to determine the 1

scanning mode MDL data listed in Table 7 and the precision and recovery data given

in Tables 9 and 10.
200.8-41

TABLE 7: METHOD DETECTION LIMITS

Element μg/L mg/kg μg/L μg/L AMU

Scanning Mode Selection Ion Monitoring Mode 1

Total Recoverable Total Recoverable Direct Analysis

2

3

Aqueous Solids Aqueous Aqueous

 Al 1.0 0.4 1.7 0.04 27

 Sb 0.4 0.2 0.04 0.02 123

 As 1.4 0.6 0.4 0.1 75

 Ba 0.8 0.4 0.04 0.04 137

 Be 0.3 0.1 0.02 0.03 9

 Cd 0.5 0.2 0.03 0.03 111

 Cr 0.9 0.4 0.08 0.08 52

 Co 0.09 0.04 0.004 0.003 59

 Cu 0.5 0.2 0.02 0.01 63

 Pb 0.6 0.3 0.05 0.02 206,207,208

 Mn 0.1 0.05 0.02 0.04 55

 Hg n.a. n.a. n.a 0.2 202

 Mo 0.3 0.1 0.01 0.01 98

 Ni 0.5 0.2 0.06 0.03 60

 Se 7.9 3.2 2.1 0.5 82

 Ag 0.1 0.05 0.005 0.005 107

 Tl 0.3 0.1 0.02 0.01 205

 Th 0.1 0.05 0.02 0.01 232

 U 0.1 0.05 0.01 0.01 238

 V 2.5 1.0 0.9 0.05 51

 Zn 1.8 0.7 0.1 0.2 66

Data acquisition mode given in Table 6. Total recoverable MDL concentrations are 1

computed for original matrix with allowance for sample dilution during preparation.

Listed MDLs for solids calculated from determined aqueous MDLs.

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

and Se were acquired using a dwell time of 4.096 seconds with 1500 area count per 82

seconds Kr present in argon supply. All other data were acquired using a dwell 83

time of 1.024 seconds per AMU monitored.

MDLs were determined from analysis of seven undigested aqueous sample aliquots. 3

n.a. - Not applicable. Total recoverable digestion not suitable for organo-mercury

compounds.
200.8-42

TABLE 8: ACCEPTANCE LIMITS FOR QC CHECK SAMPLE

METHOD PERFORMANCE (μg/L)1

Element Conc. Recovery (S ) μg/L

QC Check Standard Acceptance

Sample Average Deviation Limits 2

r

3

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 88-112

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 91-111

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

4

5

1

Method performance characteristics calculated using regression equations from

collaborative study, Reference 11.

Single-analyst standard deviation, S . 2

r

Acceptance limits calculated as average recovery ± three standard deviations. 3

Acceptance limits centered at 100% recovery. 4

Statistics estimated from summary statistics at 48 and 64 μg/L. 5
200.8-43

TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES

DRINKING WATER

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD

Sample Low Average High Average

Conc. Spike Recovery Spike Recovery

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.
200.8-44

TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS

MATRICES (Cont’d)

WELL WATER

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD

Sample Low Average High Average

Conc. Spike Recovery Spike Recovery

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.
200.8-45

TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS

MATRICES (Cont’d)

POND WATER

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD

Sample Low Average High Average

Conc. Spike Recovery Spike Recovery

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.
200.8-46

TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS

MATRICES (Cont’d)

SEWAGE TREATMENT PRIMARY EFFLUENT

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD

Sample Low Average High Average

Conc. Spike Recovery Spike Recovery

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.
200.8-47

TABLE 9: PRECISION AND RECOVERY DATA IN AQUEOUS

MATRICES (Cont’d)

INDUSTRIAL EFFLUENT

Element μg/L μg/L R (%) S (R) RPD μg/L R (%) S (R) RPD

Sample Low Average High Average

Conc. Spike Recovery Spike Recovery

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.
200.8-48

TABLE 10: PRECISION AND RECOVERY DATA IN SOLID MATRICES

EPA HAZARDOUS SOIL #884

Element (mg/kg) (mg/kg) R (%) S (R) RPD (mg/kg) R (%) S (R) RPD

Sample Low Average High Average

Conc. Spike Recovery Spike Recovery

+ +

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. +
200.8-49

TABLE 10: PRECISION AND RECOVERY DATA IN SOLID MATRICES

NBS 1645 RIVER SEDIMENT

Element (mg/kg) (mg/kg) R (%) S (R) RPD (mg/kg) R (%) S (R) RPD

Sample Low Average High Average

Conc. Spike Recovery Spike Recovery

+ +

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 * * – 

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 10: PRECISION AND RECOVERY DATA IN SOLID MATRICES

EPA ELECTROPLATING SLUDGE #286

Element (mg/kg) (mg/kg) R (%) S (R) RPD (mg/kg) R (%) S (R) RPD

Sample Low Average High Average

Conc. Spike Recovery Spike Recovery

+ +

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 * * – 

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. +
200.8-51

TABLE 11: PRIMARY DRINKING WATER CONTAMINANTS

PRECISION AND RECOVERY DATA

Analyte % Recovery S (R) (IV) (VI) (X)

Regional Sample

Background Concentration, μg/L Average Mean1

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 

The three regional waters were fortified with 1.0 μg/L of all analytes listed, except 1

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.



200.8-55
200.8-56

TABLE 13: BACKGROUND AND SPIKE MEASUREMENTS IN WAST

DIGESTATEa

Background

 Concentrate 1 Concentrate 2 

Conc.

μg/L

Std

Dev

μg/L

Spike

μg/L

Found

μg/L

Std

Dev

μg/L

% Rec

%

RSD

%

Spike

μg/L

Found

μg/L

Std

Dev

μg/L

% Rec

%

R

BeAlCrVMnCoNicuZnAsSeMoAg CdSbBaTlPbThU

0.0

78.219.5

1.9

296.6

2.5

47.377.477.4

0.84.5

166.1

0.62.73.3

68.6

0.16.90.10.4

0.0

12.4

8.12.8

24.7

0.45.0

13.2

4.91.16.29.40.71.10.23.30.10.50.10.2

100200200250125125125125200200250100200125100250100125125125

94.5

260.9222.2271.8419.0124.7161.7194.5257.4194.9236.8269.8176.0117.0100.2321.0103.3135.1140.2141.2

11.841.223.336.535.712.3

4.9

29.516.3

8.0

14.219.014.6

4.84.8

19.4

8.07.8

19.519.3

94.591.4

101.4108.0

97.997.891.593.790.097.192.9

103.7

87.791.496.9

101.0103.2102.6112.1112.6

12.515.810.513.4

8.59.93.0

15.2

6.34.16.07.08.34.14.86.07.75.8

13.913.7

125250250200100101100100250250200125250100125200125100100100

118.1309.1274.3219.3397.4100.7142.7172.3302.5244.7194.3302.0214.6

96.6

125.9279.3129.2110.3113.3113.6

14.748.526.630.134.8

9.45.6

26.621.112.8

9.3

18.017.8

3.24.3

17.2

8.96.3

15.416.0

94.592.4

101.9108.7100.8

97.295.494.990.097.694.9

108.7

85.693.998.1

105.4103.3103.4113.2113.2

Results from 10 participating laboratories. Wastewater digestate supplied with the 

amaterials. Mean background concentrations determined by the participants.
200.8-57

TABLE 14: SPIKE MEASUREMENTS IN PARTICIPANTS WASTEW

 Concentrate 1 Concentrate 2 

Spike

μg/L

Found

μg/L

Std

Dev

μg/L

% Rec

%

RSD

%

Spike

μg/L

Found

μg/L

Std

Dev

μg/L

% Rec

% RS

%

BeAlCrVMnCoNicuZnAsSeMoAgCdSbBaTlPbThU

101200200250125125125125200200250100200125100250100125125125

103.4198.7205.4246.5119.0125.8127.4126.8201.4207.3256.8

98.6

200.7123.2

92.2

245.2100.0125.8124.2130.4

12.023.912.3

4.45.47.09.75.3

36.711.926.4

4.6

48.911.5

4.4

12.8

0.95.17.6

10.3

103.4

99.4

102.7

98.695.2

100.6101.9101.4100.7103.7102.7

98.6

100.4

98.692.298.1

100.0100.6

99.4

104.3

11.612.0

6.01.84.55.67.64.2

18.2

5.7

10.3

4.7

24.4

9.34.85.20.94.16.17.9

125250250200100101100100250250200125250100125200125100100100

128.2252.4253.4196.8

95.599.5

101.0105.3246.4263.0214.0123.2231.2

95.8

119.0204.7128.0100.8

99.8

106.4

13.615.515.4

2.84.35.37.53.6

29.7

2.6

18.7

6.7

63.5

2.91.0

12.1

6.02.75.76.8

102.6101.0101.4

98.495.598.5

101.0105.3

98.6

105.2107.3

98.692.595.895.2

102.4102.4100.8

99.8

106.4

112

Results from five participating laboratories. Mean concentrations before spiking a

alisted because they varied considerably among the different wastewaters.