1、Designation: D4190 15Standard Test Method forElements in Water by Direct-Current Plasma AtomicEmission Spectroscopy1This standard is issued under the fixed designation D4190; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of dissolvedand total recoverable elements in water, which includes dri
3、nk-ing water, lake water, river water, sea water, snow, and Type IIreagent water by direct current plasma atomic emission spec-troscopy (DCP).1.2 The information on precision and bias may not apply toother waters.1.3 This test method is applicable to the 15 elements listedin Annex A1 (Table A1.1) an
4、d covers the ranges in Table 1.1.4 This test method is not applicable to brines unless thesample matrix can be matched or the sample can be diluted bya factor of 200 up to 500 and still maintain the analyteconcentration above the detection limit.1.5 The values stated in SI units are to be regarded a
5、sstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the
6、 applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1066 Practice for Sampling SteamD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19
7、 on WaterD3370 Practices for Sampling Water from Closed ConduitsD4841 Practice for Estimation of Holding Time for WaterSamples Containing Organic and Inorganic ConstituentsD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods f
8、or Water AnalysisE1097 Guide for Determination of Various Elements byDirect Current Plasma Atomic Emission Spectrometry3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 total recoverable
9、element, na descriptive term relat-ing to the elemental forms recovered in the acid-digestionprocedure specified in this test method.4. Summary of Test Method4.1 Elements are determined, either sequentially orsimultaneously, by DCP.4.2 Matrix enhancement or suppression of the emissionsignal can be m
10、inimized by the addition of 2000 mg/L oflithium ion to all standards, samples, and blanks.4.3 Dissolved elements are determined by atomizing afiltered and acidified sample directly with no pretreatment.4.4 If the sample is clear, total recoverable elements aredetermined in the same manner as dissolv
11、ed elements exceptthat sample is unfiltered and acidified.4.5 If there are large particles (non-colloidal) the totalrecoverable elements are determined on a portion of the sampleafter a hydrochloric-nitric acid digestion (12.2 12.5). Thesame digestion procedure is used to determine all total recov-e
12、rable elements in this test method.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved Feb. 1, 2015. Published March 2015. Originallyapproved in 1982. Last previou
13、s edition approved in 2008 as D4190 08. DOI:10.1520/D4190-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.
14、*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NOTE 1The volatility of mercury3, 4compounds, especially thechlorides, makes it necessary to use considerable care in dig
15、esting samplescontaining these elements. The samples must not be boiled unlessprovision is made to prevent loss by volatilization.5. Significance and Use5.1 This test method is useful for the determination ofelement concentrations in many natural waters. It has thecapability for the simultaneous det
16、ermination of up to 15separate elements. High analysis sensitivity can be achievedfor some elements, such as boron and vanadium.6. Interferences6.1 For commonly occurring matrix elements the followingspectral interferences have been observed:6.1.1 Calcium, magnesium, and boron interfere with lead at
17、405.78 nm.6.1.2 Calcium interferes with chromium at 425.43 nm.6.1.3 Magnesium interferes with cadmium at 214.44 nm.6.1.4 Iron interferes with cobalt at 345.35 and 240.73 nm.6.1.5 Cobalt interferes with nickel at 341.48 nm.NOTE 2The exact magnitude of these interferences has not beendetermined since
18、it depends on the concentration of the calibrationstandards used and the sample matrix.6.2 Some additional possible interferences are listed inAnnexA2 (TableA2.1) so that the analyst may be aware of andtest for them.7. Apparatus7.1 See the manufacturers instruction manual for installa-tion and opera
19、tion of DCP spectrometers, refer to Guide E1097for information on DCP spectrometers.8. Reagents8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatreagents shall conform to the specifications of the Committeeon Analytical Reagents o
20、f the American Chemical Society5where such specifications are available. Other grades may beused, provided it is first ascertained that the reagent is ofsufficient purity to permit its use without lessening the accu-racy of the determination.8.2 Purity of WaterUnless otherwise indicated, referenceto
21、 water shall be understood to mean reagent water conformingto Type I of Specification D1193. Other reagent water typesmay be used, provided it is first ascertained that the water is ofsufficiently high purity to permit its use without lessening thebias and precision of the determination. Type II wat
22、er wasspecified at the time of round robin testing of this test method.8.3 Stock SolutionsPreparation of stock solutions for eachelement is listed in Annex A3 (Table A3.1) or use commer-cially available, ICP Grade, stock standards.8.4 Filter PaperPurchase suitable filter paper. Typicallythe filter p
23、apers have a pore size of 0.45-m membrane.Material such as fine-textured, acid-washed, ashless paper, orglass fiber paper are acceptable. The user must first ascertainthat the filter paper is of sufficient purity to use withoutadversely affecting the bias and precision of the test method.8.4NOTE 3De
24、pending on the manufacturer, these filters have been foundto be contaminated to various degrees with heavy metals. Care should beexercised in selecting a source of these filters. A good practice is to washthe filters with nitric acid and reagent water before filtering a sample.8.5 High Purity Hydroc
25、hloric Acid, (HCl), (sp gr 1.19),concentrated hydrochloric acid.8.6 Hydrochloric Acid, (1 + 1)Add one volume of HCl(sp gr 1.19) to one volume of water.8.7 Lithium Carbonate, ultrapure.8.8 Lithium Solution (40 000 mg/L)Dissolve 213 g ofultrapure lithium carbonate in a minimum amount of HCl (spgr 1.19
26、) and dilute to 1 L with water.8.9 Concentrated Nitric Acid, (HNO3), (sp gr 1.42)High-purity acid can be prepared by distillation of concentrated nitricacid from a sub-boiling quartz still or it can be commerciallypurchased.8.10 Dilute Nitric Acid, (1+1)Add one volume of HNO3(sp. gr. 1.42) to one vo
27、lume of water.8.11 Dilute Nitric Acid, (1 + 499)Add one volume ofHNO3(sp gr 1.42) to 499 volumes of water.NOTE 4If a high reagent blank is obtained on either HNO3or HCl,distill the acid or use high purity acid. When HCl is distilled, an azeotropicmixture is obtained (approximately 6 N HCl); therefor
28、e, wheneverconcentrated HCl is specified in the preparation of a reagent or in theprocedure, use double the amount if distilled acid is used.9. Precautions9.1 Emission intensities are affected by changing viscosityso it is important to control the viscosity of blanks, standards,3Standard Methods of
29、Chemical Analysis, Editor, N. H. Furman, Vol 1, SixthEdition, pp. 107 and 657.4Smith, G. F., The Wet Chemical Oxidation of Organic Compositions, The G.Frederick Smith Chemical Co., 1965.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Sugges
30、tions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Solutions for AnalysisE
31、lement Concentration RangeAluminum 50 to 200 g/LBeryllium 50 to 1000 g/LBoron 50 to 1000 g/LCadmium 50 to 1000 g/LChromium 50 to 1000 g/LCobalt 50 to 1000 g/LCopper 50 to 1000 g/LIron 50 to 1000 g/LLead 200 to 1000 g/LManganese 50 to 1000 g/LMercury 50 to 1000 g/LNickel 50 to 1000 g/LStrontium 50 to
32、 1000 g/LVanadium 50 to 1000 g/LZinc 50 to 1000 g/LD4190 152and samples within reasonable limits. Reagent water standardsshould not be used to analyze oil field brines. Alternatively,matrix matching or the method of additions can be used.9.2 Organic solvents, such as alcohol, acetone, and methylethy
33、l ketone have been observed to enhance emission intensity.This enhancement effect must be compensated for whenorganic solvents are known to be present. Alternatively, matrixmatching or the method of additions can be used.10. Sampling10.1 Collect the samples in accordance with the applicablestandards
34、, Practice D1066 or Practices D3370.10.2 Preserve the samples by immediately adding highpurity nitric acid to adjust the pH to two at the time ofcollection. Normally 2 mL of HNO3is required per liter ofsample. If only dissolved elements are to be determined, (Note5) filter the sample through a 0.45
35、m membrane filter beforeacidification. The holding time for the sample may be calcu-lated in accordance with Practice D4841.NOTE 5Alternatively, the pH may be adjusted in the laboratory if thesample is returned within 14 days. However, acid must be added at least24 hours before analysis to dissolve
36、any metals that adsorb to the containerwalls. This could reduce hazards of working with acids in the field whenappropriate.11. Calibration and Standardization11.1 Prepare 100 mL of a blank and at least four standardsolutions to bracket the expected concentration range of thesamples to be analyzed by
37、 diluting 5.0 mL of lithium solution(see 8.8) and an appropriate volume of stock solution withHNO3(1 + 499). Prepare the blank and standards each time thetest is to be run or as determined by Practice D4841.11.2 Analyze at least four working standards containingconcentrations of each element that br
38、acket the expectedsample concentration, prior to analysis of samples, to calibratethe instrument.Atomize the blank and standards and record theemission intensity or concentration. Atomize HNO3(1 + 499)between each standard.11.3 Using the instrument software verify that the instru-ment calibration is
39、 within user acceptable QC limits.12. Procedure12.1 To determine dissolved elements, add 5.0 mL oflithium solution (see 8.8) to a 100.0 mL volumetric flask andbring to volume with the well-mixed acidified sample. Proceedwith 12.6.12.2 When determining total recoverable elements in solu-tions contain
40、ing suspended matter or large particles (that is,noncolloidal), add 5.0 mL of HNO3(sp. gr. 1.42) (8.9) and 5.0mL of lithium solution (8.8) to a 100.0-mL sample.NOTE 6When digestion is necessary, subject the standards, sample,and blank to the same procedure.12.3 Add 5.0 mL of HCl (sp. gr. 1.19) (8.5)
41、 to each sample.12.4 Heat the samples in a covered beaker on a steam bathor hot plate until the volume has been reduced to 15 or 20 mL.Take care to see that the samples do not boil. Loss of samplecould result from bumping or spattering.NOTE 7For samples with high levels of dissolved solids, the amou
42、ntof reduction in volume is left to the discretion of the analyst.NOTE 8Many laboratories have found block digestion systems auseful way to digest samples for trace metals analysis. Systems typicallyconsist of either a metal or graphite block with wells to hold digestiontubes. The block temperature
43、controller must be able to maintain unifor-mity of temperature across all positions of the block. For trace metalsanalysis, the digestion tubes should be constructed of polypropylene andhave a volume accuracy of at least 0.5 %. All lots of tubes should comewith a certificate of analysis to demonstra
44、te suitability for their intendedpurpose.12.5 Cool and filter (8.4) the samples, if necessary, througha fine ashless filter paper into 100.0 mL volumetric flasks.Wash the filter paper three times with water and adjust tovolume.12.6 Atomize each solution and record its emission intensityor concentrat
45、ion. Atomize HNO3(1 + 499) (8.11) betweensamples.13. Calculation13.1 Calculate the concentration of elements in eachsample, in g/L, using the calibrations established in 11.3.Modern DCP instruments will provide the results in thecalibrated concentration units.13.2 Multiply the results for dissolved
46、elements by thedilution factor of 1.05 to correct for the required addition oflithium solution (12.1).NOTE 9The correction does not need to be applied to samplesanalyzed using the total recoverable process because those samples areadjusted to volume. If the block digestion systems reflux the samples
47、without any loss of volume the dilution factor will need to be applied.14. Precision and Bias614.1 To facilitate handling and distribution for round robintesting, three concentrated solutions were prepared. These wereacidified solutions of 15 elements.14.2 The concentrated solutions, when diluted ac
48、cording todirections, yielded solutions for analysis with the compositionas shown in Table 2. A total of eight laboratories and thirteenoperators participated in this study.14.2.1 Type II water was specified at the time of round robintesting of this test method.14.3 PrecisionThe precision of this te
49、st method for theelements tested within their respective ranges of concentrationgiven in Table 2 may be expressed as given in Table 3.14.4 BiasSee Table 4.14.5 This section on precision and bias conforms to PracticeD2777 77 which was in place at the time of collaborativetesting. Under the allowances made in 1.4 of PracticeD2777 13, these precision and bias data do meet existingrequirements of interlaboratory studies of Committee D19 testmethods.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by req
