EPA 200.2

SAMPLE PREPARATION PROCEDURE FOR SPECTROCHEMICAL

DETERMINATION OF TOTAL RECOVERABLE ELEMENTS

Revision 2.8EMMC Version

T.D. Martin, E.R. Martin, and S.E. Long (Technology Applications, Inc.) - Method 200.2,Revision 1.1 (19)

T.D. Martin, S.E. Long (Technology Applications Inc.), and J.T. Creed - Method 200.2,Revision 2.3 (1991)

T.D. Martin, J.T. Creed, and C.A. Brockhoff - Method 200.2, Revision 2.8 (1994)

ENVIRONMENTAL MONITORING SYSTEMS LABORATORY

OFFICE OF RESEARCH AND DEVELOPMENTU. S. ENVIRONMENTAL PROTECTION AGENCY

CINCINNATI, OHIO 45268

200.2-1

METHOD 200.2

SAMPLE PREPARATION PROCEDURE FOR SPECTROCHEMICAL DETERMINATION

OF TOTAL RECOVERABLE ELEMENTS1.0

SCOPE AND APPLICATION1.1

This method provides sample preparation procedures for the determination oftotal recoverable analytes in groundwaters, surface waters, drinking waters,wastewaters, and, with the exception of silica, in solid type samples such assediments, sludges and soils.1 Aqueous samples containing suspended orparticulate material ≥1% (W/V) should be extracted as a solid type sample. This method is applicable to the following analytes:

Chemical Abstract ServicesRegistry Number (CASRN)

(Al)(Sb)(As)(B)(Ba)(Be)(Cd)(Ca)(Cr)(Co)(Cu)(Fe)(Pb)(Li)(Mg)(Mn)(Hg)(Mo)(Ni)(P)(K)(Se)(SiO2)(Ag)(Na)(Sr)

7429-90-57440-36-07440-38-27440-42-87440-39-37440-41-77440-43-97440-70-27440-47-37440-48-47440-50-87439--67439-92-17439-93-27439-95-47439-96-57439-97-67439-98-77440-02-07723-14-07440-09-77782-49-27631-86-97440-22-47440-23-57440-24-6

AnalyteAluminumAntimonyArsenicBoronBariumBerylliumCadmiumCalciumChromiumCobaltCopperIronLeadLithiumMagnesiumManganeseMercury

MolybdenumNickel

PhosphorusPotassiumSeleniumSilicaaSilverSodiumStrontium

a

This method is not suitable for the determination of silica in solids.200.2-2

AnalyteThalliumThoriumTin

UraniumVanadiumZinc

1.2

(Tl)(Th)(Sn)(U)(V)(Zn)

Chemical Abstract ServicesRegistry Number (CASRN)

7440-28-07440-29-17440-31-57440-61-17440-62-27440-66-6

For reference where this method is approved for use in compliance monitoringprograms [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 fordrinking water), and the latest Federal Register announcements.

Samples prepared by this method can be analyzed by the following methodsgiven in this supplement: Method 200.7, Determination of Metals and TraceElements by Inductively Coupled Plasma-Atomic Emission Spectrometry;Method 200.8, Determination of Trace Elements By Inductively CoupledPlasma-Mass Spectrometry; and Method 200.9, Determination of TraceElements by Stabilized Temperature Graphite Furnace Atomic AbsorptionSpectrometry. Also, this method can be used prior to analysis by directaspiration flame atomic absorption for the above list of analytes with theexception of the following: As, B, Hg, P, Se, SiO2, Th, and U.

The preparation procedures described in this method are not recommendedprior to analysis by the conventional graphite furnace technique, commonlyrefered to as \"off-the-wall\believed that the resulting chloride concentration in the prepared solutions cancause either analyte volatilization loss prior to atomization or an unremediablechemical vapor state interference for some analytes when analyzed using theconventional graphite furnace technique.

This method is suitable for preparation of aqueous samples containing silverconcentrations up to 0.1 mg/L. For the analysis of wastewater samplescontaining higher concentrations of silver, succeeding smaller volume, wellmixed aliquots must be prepared until the analysis solution contains <0.1mg/L silver. The extraction of solid samples containing concentrations ofsilver >50 mg/kg should be treated in a similar manner. Also, the extractionof tin from solid samples should be prepared again using aliquots <1 g whendetermined sample concentrations exceed 1%.

When using this method for determination of boron and silica in aqueoussamples, only plastic or quartz labware should be used from the time ofsample collection to the completion of the analysis. For accurate

determinations of boron in solid samples only quartz or PTFE beakers should

200.2-3

1.3

1.4

1.5

1.6

be used during acid extraction with immediate transfer of an extract aliquot toa plastic centrifuge tube following dilution of the extract to volume. Whenpossible, borosilicate glass should be avoided to prevent contamination ofthese analytes.

1.7

This method will solubilize and hold in solution only minimal concentrationsof barium in the presence of free sulfate. For the analysis of barium insamples having varying and unknown concentrations of sulfate, analysisshould be completed as soon as possible after sample preparation.

This method is not suitable for the determination of volatile low boiling pointorgano-mercury compounds.

1.8

2.0

SUMMARY OF METHOD2.1

Solid and aqueous samples are prepared in a similar manner for analysis. Nitric and hydochloric acids are dispensed into a beaker containing an

accurately weighed or measured, well mixed, homogeneous aqueous or solidsample. Aqueous samples are first reduced in volume by gentle heating.

Then, metals and toxic elements are extracted from either solid samples or theundissolved portion of aqueous samples by covering the beaker with a watchglass and refluxing the sample in the dilute acid mixture for 30 minutes. Afterextraction, the solubilzed analytes are diluted to specified volumes with ASTMType I water, mixed and either centrifuged or allowed to settle overnightbefore analysis. Diluted samples are to be analyzed by the appropriate massand/or atomic spectrometry methods as soon as possible after preparation.

3.0DEFINITIONS3.1

Field Reagent Blank (FRB) - An aliquot of reagent water or other blank matrixthat is placed in a sample container in the laboratory and treated as a samplein 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 otherinterferences are present in the field environment (Section 8.3).

Solid Sample - For the purpose of this method, a sample taken from materialclassified as either soil, sediment or sludge.

Total Recoverable Analyte - The concentration of analyte determined to be ineither a solid sample or an unfiltered aqueous sample following treatment byrefluxing with hot dilute mineral acid.

Water Sample - For the purpose of this method, a sample taken from one ofthe following sources: drinking, surface, ground, storm runoff, industrial ordomestic wastewater.

3.23.3

3.4

200.2-4

4.0INTERFERENCES4.1

In sample preparation, contamination is of prime concern. The work area,

including bench top and fume hood, should be periodically cleaned in order toeliminate environmental contamination.

Chemical interferences are matrix dependent and cannot be documentedprevious to analysis.

Boron and silica from the glassware will grow into the sample solution duringand following sample processing. For critical determinations of boron andsilica, only quartz and/or PTFE plastic labware should be used. When quartzbeakers are not available for extraction of solid samples, to reduce boroncontamination, immediately transfer an aliquot of the diluted extract to a

plastic centrifuge tube for storage until time of analysis. A series of laboratoryreagent blanks can be used to monitor and indicate the contamination effect.

4.24.3

5.0SAFETY5.1

All personnel handling environmental samples known to contain or to havebeen in contact with human waste should be immunized against knowndisease causative agents.

The acidification of samples containing reactive materials may result in therelease of toxic gases, such as cyanides or sulfides. Acidification of samplesshould be done in a fume hood.

Material safety data sheets for all chemical reagents should be available to andunderstood by all personnel using this method. Specifically, concentratedhydrochloric acid and concentrated nitric acid are moderately toxic andextremely irritating to skin and mucus membranes. Use these reagents in ahood whenever possible and if eye or skin contact occurs, flush with largevolumes of water. Always wear safety glasses or a shield for eye protectionwhen working with these reagents.2,3,4

5.2

5.3

6.0EQUIPMENT AND SUPPLIES6.16.26.36.4

Analytical balance, with capability to measure to 0.1 mg, for use in weighingsolids, and for determining dissolved solids in extracts.

Single pan balance, with capability of weighing to 0.01 g, for use in rapidweighing solids and liquids or samples in excess of 10 g.

A temperature adjustable hot plate capable of maintaining a temperature of95°C.

(Optional) A temperature adjustable block digester capable of maintaining atemperature of 95°C and equipped with 250 mL constricted digestion tubes.

200.2-5

6.56.66.76.86.96.10

(Optional) A steel cabinet centrifuge with guard bowl, electric timer andbrake.

A gravity convection drying oven with thermostatic control capable ofmaintaining 180°C ± 5°C.

(Optional) An air displacement pipetter capable of delivering volumes rangingfrom 0.1 to 2500 µL with an assortment of high quality disposable pipet tips. Mortar and pestle, ceramic or nonmetallic material.Polypropylene sieve, 5-mesh (4 mm opening).

Labware - For determination of trace levels of elements, contamination andloss are of prime consideration. Potential contamination sources include

improperly cleaned laboratory apparatus and general contamination within thelaboratory environment from dust, etc. A clean laboratory work areadesignated for trace element sample handling must be used. Sample

containers can introduce positive and negative errors in the determination oftrace elements by (1) contributing contaminants through surface desorption orleaching, (2) depleting element concentrations through adsorption processes. All reusable labware (glass, quartz, polyethylene, PTFE, FEP, etc.) should besufficiently clean for the task objectives. Several procedures found to provideclean labware include soaking overnight and thoroughly washing with

laboratory-grade detergent and water, rinsing with tap water, and soaking forfour hours or more in 20% (V/V) nitric acid or a mixture of dilute nitric andhydrochloric acid (1+2+9), followed by rinsing with ASTM Type I grade waterand storing clean.

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

6.10.1Glassware - Volumetric flasks, graduated cylinders, funnels and

centrifuge tubes (glass and/or metal free plastic).6.10.2Assorted calibrated pipettes.

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

50 mm watch glasses.6.10.4Griffin 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.6.10.6Evaporating dishes or high-form crucibles, porcelain, 100 mL capacity. 6.10.7Wash bottle - One piece stem, Teflon FEP bottle with Tefzel ETFE screw

closure, 125 mL capacity.

200.2-6

7.0REAGENTS AND STANDARDS7.1

Reagents may contain elemental impurities which might affect analytical data. High-purity reagents should be used whenever possible. All acids used forthis method must be of ultra high-purity grade.7.1.17.1.27.1.37.1.47.1.5

7.2

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

Nitric acid (1+1) -- Add 500 mL conc. nitric acid to 400 mL of ASTMType I water and dilute to 1 L.

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

Hydrochloric acid (1+1) -- Add 500 mL conc. hydrochloric acid to 400mL of ASTM Type I water and dilute to 1 L.

Hydrochloric acid (1+4) -- Add 200 mL conc. hydrochloric acid to 400mL of ASTM Type I water and dilute to 1 L.

Reagent water -- For all sample preparation and dilutions, ASTM Type I water(ASTM D1193)5 is required. Suitable water may be prepared by passingdistilled water through a mixed bed of anion and cation exchange resins.Refer to the appropriate analytical method for the preparation of standardstock solutions, calibration standards, and quality control solutions.

7.3

8.0

SAMPLE COLLECTION, PRESERVATION, AND STORAGE8.1

For determination of total recoverable elements in aqueous samples, thesamples must be acid preserved prior to aliquoting for either sample

processing or determination by direct spectrochemical analysis. For properpreservation samples are not filtered, but acidified with (1+1) nitric acid to pH<2. Preservation may be done at the time of sample collection, however, toavoid the hazards of strong acids in the field, transport restrictions, and

possible contamination it is recommended that the samples be returned to thelaboratory within two weeks of collection and acid preserved upon receipt inthe laboratory. Following acidification, the sample should be mixed and heldfor 16 hours. (Normally, 3 mL of (1+1) nitric acid per liter of sample issufficient for most ambient and drinking water samples). The pH of all

aqueous samples must be tested immediately prior to withdrawing an aliquotfor processing to ensure the sample has been properly preserved. If for somereason such as high alkalinity the sample pH is verified to be >2, more acidmust be added and the sample held for 16 hours until verified to be pH <2. Ifproperly acid preserved, the sample can be held up to six months beforeanalysis.

200.2-7

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

hazardous, acidification should be done in a fume hood. See Section5.2.

8.28.3

Solid samples require no preservation prior to analysis other than storage at4°C. There is no established holding time limitation for solid samples.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 samplecollection.

9.0QUALITY CONTROL9.1

Each laboratory determining total recoverable elements is required to operate aformal quality control (QC) program. The minimum requirements of a QCprogram consist of an initial demonstration of laboratory capability, and theanalysis of laboratory reagent blanks, fortified blanks and quality control

samples as a continuing check on performance. The laboratory is required tomaintain performance records that define the quality of data generated.Specific instructions on accomplishing the described aspects of the QCprogram are discussed in the analytical methods (Section 1.3).

9.2

10.

CALIBRATION AND STANDARDIZATION10.1

Not applicable. Follow instructions given in the analytical method selected.

11.0PROCEDURE11.1

Aqueous Sample Preparation -- Total Recoverable Analytes

11.1.1For the determination of total recoverable analytes in aqueous samples,

transfer a 100 mL (±1 mL) aliquot from a well mixed, acid preservedsample to a 250 mL Griffin beaker (Sections 1.2, 1.5, 1.6, 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 materialshould be cautiously evaporated to near 10 mL and extracted using theacid-mixture procedure described in Sections 11.2.3 through 11.2.8.

11.1.2Add 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 onthe hot plate for solution evaporation. The hot plate should be locatedin a fume hood and previously adjusted to provide evaporation at atemperature of approximately but no higher than 85°C. (See the

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

200.2-8

glass or other necessary steps should be taken to prevent samplecontamination from the fume hood environment.

Note: For proper heating adjust the temperature control of the hotplate such that an uncovered Griffin beaker containing 50 mL of waterplaced in the center of the hot plate can be maintained at a temperatureapproximately but no higher than 85°C. (Once the beaker is coveredwith a watch glass the temperature of the water will rise toapproximately 95°C.)

11.1.3Reduce 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 a100 mL aliquot with the rate of evaporation rapidly increasing as thesample volume approaches 20 mL. (A spare beaker containing 20 mLof water can be used as a gauge.)11.1.4Cover the lip of the beaker with a watch glass to reduce additional

evaporation and gently reflux the sample for 30 minutes. (Slightboiling may occur, but vigorous boiling must be avoided to preventloss of the HCl-H2O azeotrope.)11.1.5Allow the beaker to cool. Quantitatively transfer the sample solution to

a 50 mL volumetric flask, make to volume with reagent water, stopperand mix.11.1.6Allow any undissolved material to settle overnight, or centrifuge a

portion of the prepared sample until clear. (If after centrifuging orstanding overnight the sample contains suspended solids that wouldclog the nebulizer, a portion of the sample may be filtered for theirremoval prior to analysis. However, care should be exercised to avoidpotential contamination from filtration.) The sample is now ready foranalysis by either inductively coupled plasma-atomic emissionspectrometry or direct aspiration flame and stabilized temperature

graphite furnace atomic absorption spectroscopy (Sections 1.3 and 1.4). 11.1.7To ready the sample for analyses by inductively coupled plasma-mass

spectrometry (Section 1.3), 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 solidsin this solution are >0.2%, additional dilution may be required toprevent clogging of the extraction and/or skimmer cones. Internalstandards are added at the time of analysis.)11.1.8Because the effects of various matrices on the stability of diluted

samples cannot be characterized, all analyses should be performed assoon as possible after the completed preparation.

11.2

Solid Sample Preparation -- Total Recoverable Analytes

200.2-9

11.2.1For the determination of total recoverable analytes in solid samples,

mix the sample thoroughly and transfer a portion (>20 g) to taredweighing dish, weigh the sample and record the wet weight. (Forsamples with <35% moisture a 20 g portion is sufficient. For sampleswith moisture >35% a larger aliquot 50-100 g is required.) Dry thesample to a constant weight at 60°C and record the dry weight for

calculation of percent solids (Section 12.1). (The sample is dried at 60°Cto prevent the loss of mercury and other possible volatile metallic

compounds, to facilitate sieving, and to ready the sample for grinding.)11.2.2To 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 thedried, ground material weigh accurately a representative 1.0 ± 0.01 galiquot (W) of the sample and transfer to a 250 mL Phillips beaker foracid extraction (Sections 1.5, 1.6, 1.7, and 1.8).11.2.3To the beaker add 4 mL of (1+1) HNO3 and 10 mL of (1+4) HCl. Cover

the lip of the beaker with a watch glass. Place the beaker on a hotplate for reflux extraction of the analytes. The hot plate should belocated in a fume hood and previously adjusted to provide a refluxtemperature of approximately 95°C. (See the following note.)

Note: For proper heating adjust the temperature control of the hotplate such that an uncovered Griffin beaker containing 50 mL of waterplaced in the center of the hot plate can be maintained at a temperatureapproximately but no higher than 85°C. (Once the beaker is coveredwith a watch glass the temperature of the water will rise to

approximately 95°C.) Also, a block digester capable of maintaining atemperature of 95°C and equipped with 250 mL constricted volumetricdigestion tubes may be substituted for the hot plate and conical beakersin the extraction step.

11.2.4Heat the sample and gently reflux for 30 minutes. Very slight boiling

may occur, however vigorous boiling must be avoided to prevent lossof the HCl-H2O azeotrope. Some solution evaporation will occur (3-4mL).11.2.5Allow the sample to cool and quantitatively transfer the extract to a

100 mL volumetric flask. Dilute to volume with reagent water, stopperand mix. 11.2.6Allow the sample extract solution to stand overnight to separate

insoluble material or centrifuge a portion of the sample solution untilclear. (If after centrifuging or standing overnight the extract solutioncontains suspended solids that would clog the nebulizer, a portion ofthe extract solution may be filtered for their removal prior to analysis. However, care should be exercised to avoid potential contamination

200.2-10

from filtration.) The sample is now ready for analysis by eitherinductively coupled plasma-atomic emission spectrometry or directaspiration flame and stabilized temperature graphite furnace atomicabsorption spectroscopy (Sections 1.3 and 1.4).

11.2.7To ready the sample for analyses by inductively coupled plasma-mass

spectrometry (Section 1.3), adjust the chloride concentration by

pipetting 10 mL of the prepared solution into a 50 mL volumetric flask,dilute to volume with reagent water and mix. (If the dissolved solidsin this solution are >0.2%, additional dilution may be required toprevent clogging of the extraction and/or skimmer cones. Internalstandards are added at the time of analysis.) 11.2.8Because the effects of various matrices on the stability of diluted

samples cannot be characterized, all analyses should be performed assoon as possible after the completed preparation.

11.3

12.0

Sample Analysis -- Use an analytical method listed in Section 1.3.

DATA ANALYSIS AND CALCULATIONS12.1

To report percent solids in solid samples (Section 11.2) calculate as follows:

where:

DW =Sample weight (g) dried at 60°CWW =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 inSection 11.2.1 using a separate portion (>20 g) of the sample and dry toconstant weight at 103-105°C.

12.2

13.0

Calculation and treatment of determined analyte data are discussed inanalytical methods listed in Section 1.3.

METHOD PERFORMANCE13.1

Not applicable. Available data included in analytical methods listed inSection 1.3.

14.0POLLUTION PREVENTION200.2-11

14.1

Pollution prevention encompasses any technique that reduces or eliminates thequantity or toxicity of waste at the point of generation. Numerous

opportunities for pollution prevention exist in laboratory operation. The EPAhas established a preferred hierarchy of environmental management techniquesthat 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 feasiblyreduced at the source, the Agency recommends recycling as the next bestoption.

For information about pollution prevention that may be applicable tolaboratories and research institutions, consult “Less is Better: LaboratoryChemical Management for Waste Reduction”, available from the AmericanChemical Society's Department of Government Relations and Science Policy,1155 16th Street N.W., Washington D.C. 20036, (202)872-4477.

14.2

15.0WASTE MANAGEMENT15.1

The Environmental Protection Agency requires that laboratory waste

management practices be conducted consistent with all applicable rules andregulations. The Agency urges laboratories to protect the air, water, and landby 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 WasteManagement Manual for Laboratory Personnel”, available from the AmericanChemical Society at the address listed in the Section 14.2.

16.0REFERENCES1.

Martin, T.D. and E.R. Martin, \"Evaluation of Method 200.2 Sample PreparationProcedure for Spectrochemical Analyses of Total Recoverable Elements\

December 19, U.S. Environmental Protection Agency, Office of Research andDevelopment, Environmental Monitoring Systems Laboratory, Cincinnati,Ohio 45268.

\"OSHA Safety and Health Standards, General Industry\Occupational Safety and Health Administration, OSHA 2206, revisedJanuary 1976.

\"Safety in Academic Chemistry Laboratories\Publication, Committee on Chemical Safety, 3rd Edition, 1979.

\"Proposed OSHA Safety and Health Standards, Laboratories\Safety and Health Administration, Federal Register, July 24, 1986.Annual Book of ASTM Standards, Volume 11.01.

2.

3.4.5.

200.2-12