1、Designation: E1097 12 (Reapproved 2017)Standard Guide forDetermination of Various Elements by Direct CurrentPlasma Atomic Emission Spectrometry1This standard is issued under the fixed designation E1097; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the year 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. Scope1.1 This guide covers procedures for using a Direct CurrentPlasma Atomic Emission Spectrom
3、eter (DCP-AES) to deter-mine the concentration of elements in solution. Recommenda-tions are provided for preparing and calibrating the instrument,assessing instrument performance, diagnosing and correctingfor interferences, measuring test solutions, and calculatingresults. A method to correct for i
4、nstrument drift is included.1.2 This guide does not specify all the operating conditionsfor a DCP-AES because of the differences between models ofthese instruments. Analysts should follow instructions pro-vided by the manufacturer of the particular instrument.1.3 This guide does not attempt to speci
5、fy in detail all of thehardware components and computer software of the instru-ment. It is assumed that the instrument, whether commerciallyavailable, modified, or custom built, will be capable of per-forming the analyses for which it is intended, and that theanalyst has verified this before perform
6、ing the analysis.1.4 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 applica-bility of regulatory limitations prior to us
7、e. Specific precau-tionary statements are given in Section 7.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendation
8、s issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemi
9、cal Analysis of Metals, Ores, andRelated MaterialsE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performa
10、nce of an Analytical Method3. Terminology3.1 Definitions: For definitions of terms used in this guide,refer to Terminology E135.3.2 Definitions of Terms Specific to This Standard:3.2.1 background equivalent concentration (BEC), ninDCP-AES, the analyte concentration whose signal is equivalentto the s
11、ignal generated by the plasma and matrix at the analyteline when the actual analyte concentration is zero.3.2.2 detection limit (DL), nin addition to the DL definedin Terminology E135, the following detection limits aredescribed and used in this guide:3.2.2.1 instrumental detection limit (IDL), nin
12、DCP-AES,the analyte concentration corresponding to three times thestandard deviation of the background noise beneath the analyteline on a set of nine consecutive 10-s measurements of thebackground intensity of the blank.3.2.2.2 method detection limit (MDL), n in DCP-AES, thedetection limit measured
13、on the matrix blank.1This guide is under the jurisdiction of ASTM Committee E01 on AnalyticalChemistry for Metals, Ores, and Related Materials and is the direct responsibility ofSubcommittee E01.20 on Fundamental Practices.Current edition approved May 1, 2017. Published June 2017. Originallyapproved
14、 in 1986. Last previous edition approved in 2012 as E1097 12. DOI:10.1520/E1097-12R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandardsvolume information, refer to the standards Document Summary
15、page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for
16、 theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1Mon Apr 30 18 3.2.3 equivalent analyte concentration, nthe apparentconcentration of an interfering element on an anlalyte.3.2.4 linear dynamic ra
17、nge, nthe concentration rangefrom the limit of quantification to the highest concentration thatremains within 6 10 % of linearity based on lower concentra-tions.3.2.5 limit of quantification (LOQ), nthe lowest concen-tration at which the instrument can measure reliably with adefined error and confid
18、ence level.3.2.6 sensitivity, nthe slope of the analytical curve, whichis the ratio of the change in emission intensity to the change inconcentration.4. Summary of Guide4.1 Direct Current Plasma atomic emission spectrometers,either simultaneous or sequential, measure the concentration ofelements in
19、solution. Samples, calibration and other solutionsare nebulized and the aerosol is transported to the direct currentplasma jet where excitation occurs and characteristic emissionspectra are produced. The spectra are dispersed by an echellegrating and cross-dispersed by a prism or grating. The spectr
20、athen impinge on photomultiplier tubes, whose outputs areinterpreted by a microprocessor/PC as emission intensities.Background correction can be used to compensate for someinterferences. The microprocessor/PC generates calibrationcurves and calculates analyte concentration.5. Significance and Use5.1
21、 Analyses using DCP-AES require proper preparation oftest solutions, accurate calibration, and control of analyticalprocedures. ASTM test methods that refer to this guide shallprovide specifics on test solutions, calibration, and procedures.5.2 DCP-AES analysis is primarily concerned with testingmat
22、erials for compliance with specifications, but may rangefrom qualitative estimations to umpire analysis. These mayinvolve measuring major and minor constituents or traceimpurities, or both. This guide suggests some approaches tothese different analytical needs.5.3 This guide assists analysts in deve
23、loping new methods.5.4 It is assumed that the users of this guide will be trainedanalysts capable of performing common laboratory proceduresskillfully and safely. It is expected that the work will beperformed in a properly equipped laboratory.5.5 This guide does not purport to define all of the qual
24、ityassurance parameters necessary for DCP-AES analysis. Ana-lysts should ensure that proper quality assurance proceduresare followed, especially those defined by the test method. Referto Guide E882.6. Preparation of Solutions6.1 Solutions are prepared for different purposes. Not allmay be necessary
25、for every test. Prepare only those directed bythe method or required to meet specific experimental objec-tives.6.2 Rinse SolutionPrepare a rinse solution to contain theacids or bases present in the test solution at the sameconcentration. Prepare a quantity sufficient to clean the end ofthe sample up
26、take tubing and to flush the sample introductionsystem between each determination of calibration solutions andtest solutions. Occasionally, an analyte requires a conditioningtime in the aspiration/nebulization system of the instrument. Inthis case, use the test solution as a rinse and allow a suffic
27、ientresidence time before taking a reading.6.3 Reagent Blank SolutionThis solution consists of allreagents and other additions at the same concentration used inpreparing the test solution. Carry this solution through theentire sample preparation procedure.6.4 Matrix Blank SolutionPrepare this soluti
28、on to be asclose in composition to the test solution as possible (includingdissolution reagents and matrix elements), but omitting theelements to be determined. The matrix elements should be ofhigh purity.6.5 ControlSelect a reference material or other material ofknown composition and prepare it as
29、directed in the testmethod. Analyze the control regularly as a blind sample anduse the results for quality control as directed in Guide E882.6.6 Calibration SolutionsThe number and type of thesesolutions will depend on the method, and on the type ofDCP-AES instrument and its microprocessor/PC. Gener
30、ally,prepare two instrument calibration solutions, one highconcentration, and one low concentration or a blank, thatbracket the expected concentration range of the sample testsolutions. More may be prepared if the microprocessor/PC canutilize them, especially if the analyte composition of the testso
31、lutions is expected to cover a wide range or if the calibrationcurve is non-linear. Prepare the calibration solutions by addingaliquots from stock solutions to solutions that are similar to thematrix of the test sample.6.6.1 Match the matrix of the calibration solutions asclosely as possible to that
32、 of the test solution in acidity, totalsolids, reagents, and matrix elements, especially if easilyionized elements (EIE) are present. Some matrix elements maybe eliminated if it can be shown by spike addition or standardadditions that the effect on the test solution analytes isinsignificant. Use sto
33、ck solutions or pure elements prepared bya method similar to that used to prepare the test solutions. If thecomposition of the test solution is unknown to the extent thatmatrix-matched solutions cannot be prepared, or if a suffi-ciently pure matrix material is not available, refer to themethod of st
34、andard additions described in 6.7 and 10.6.NOTE 1If the instrument is designed to use a blank as the lowconcentration calibration solution, prepare it the same way as the highconcentration calibration solution is prepared, omitting the elements to bedetermined. Where matrix-matched calibration solut
35、ions are employed,this will be the matrix blank solution.6.6.2 Optimum Calibration Solution ConcentrationRangeFor calibration in the linear range, the highest concen-tration should be no more than 85 % of the upper limit of thecalibration curve linearity. For an instrument that accepts a lowconcentr
36、ation calibration solution, its concentration should beat least four times the method detection limit and above thelimit of quantification (LOQ).E1097 12 (2017)2Mon Apr 30 18 6.7 Standard Additions SolutionsPrepare as directed ineither 6.7.1 or 6.7.2 as follows:6.7.1 Prepare four separate test solut
37、ions of the sample. Toall but one, add known amounts of the analyte equal to (0.5,1.0, and 1.5) times or (1.0, 2.0, and 3.0) times the expectedconcentration of the analyte(s) in the test solution. The originalanalyte concentration must be at or above its LOQ. The finalanalyte concentration in the hi
38、ghest spike must not be greaterthan the linear range of the emission line used. Dilute allsolutions to the mark and mix. Prepare an equal volume of thereagent blank solution when using 10.6.2.6.7.2 Transfer four equal volumes of a test solution to fourvolumetric flasks of the same size. To all but o
39、ne, add knownamounts of the analyte equal to 0.5, 1.0, and 1.5, or 1.0, 2.0,and 3.0 times the expected concentration of the analyte(s) inthe test solution. The final analyte concentration in the testsolution should be at or above the LOQ. The final analyteconcentration in the highest spike should no
40、t exceed the lineardynamic range of the emission line used. Dilute all solutions tothe mark and mix. Prepare an equal volume of the reagentblank solution if using 10.6.2. Multiply the final value by afactor to compensate for dilution.6.8 Calibration Verification SolutionTo verify thecalibration, pre
41、pare one or more solutions whose concentra-tions are between the highest concentration calibration solutionand the LOQ.6.9 Spike Recovery SamplePrepare a test solution asdirected in the method. Add a spike of the analyte(s) equal toat least 5 times each analytes LOQ.6.10 Limit of Quantification (LOQ
42、) SolutionPrepare asolution containing amounts of analyte three times to six timesthe method detection limit or 10 % to 20 % of the BEC andmatched as closely to the matrix as possible.7. Hazards7.1 Protect eyes from the intense ultraviolet (UV) radiationof the plasma.7.2 Follow the manufacturers rec
43、ommended operatingpractices for initiating the plasma and operating the instrument.7.3 Ensure that HF-resistant materials are used when ana-lyzing solutions containing HF. Avoid strongly caustic solu-tions that may cause the ceramic sleeves of the electrodes tofuse.7.4 For other safety precautions,
44、refer to Practice E50.8. Characterization of Analytical Lines8.1 Overview:8.1.1 When researching a new method, use the recommen-dations in this section to select a wavelength and evaluate thepossible interferences. Measure the approximate linear range,BEC, sensitivity, LOQ experimentally, and ascert
45、ain that theyare adequate for the analysis. Once these have been establishedfor a specific instrument, periodic confirmation is recom-mended and especially whenever a change is made in thehardware (for example, transport or detection devices) oroptics. Confirm by analysis of controls, including LOQ
46、mea-surements when required, that the daily performance of theinstrument meets the criteria of the method.8.1.2 When adapting a documented test method for the firsttime, confirm that freedom from interferences, linearity, DL,LOQ and sensitivity meet the criteria of the method.8.1.3 For lists of wave
47、lengths and information on theircharacteristics, refer to Harrison,3Meggers,4Phelps,5Reader,6or Winge.78.1.3.1 In the laddered array of spectra from the DCPsechelle grating, some wavelengths appear in two adjacentorders. These wavelengths usually have similar intensities.Occasionally, one may prove
48、more useful for a specificapplication.8.2 InterferencesSeveral types of interferences may affectmeasurements. This is especially true for test solutions con-taining high concentrations of solids or acids or containingelements having intense emission, a large number of atomicemission lines, or high c
49、oncentrations of easily ionized ele-ments (EIEs). The presence of interferences should be consid-ered when selecting calibration solutions and the method ofanalysis. See 8.2.3 for suggestions on how to compensate forinterferences.8.2.1 Types of Interference:8.2.1.1 Chemical InterferencesEffects from excitation,molecular compound formation, and solvent vaporization.8.2.1.2 Physical InterferencesFactors that change the rateof sample delivery such as viscosity, surface tension, andreaction with parts of the sample delivery system.8.2.1.3 Spectral Int
