1、Designation: E 1852 08Standard Test Method forDetermination of Low Levels of Antimony in Carbon andLow-Alloy Steel by Graphite Furnace Atomic AbsorptionSpectrometry1This standard is issued under the fixed designation E 1852; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of antimonyin carbon
3、and low-alloy steel in the 0.0005 % through 0.010 %range.1.2 If this test method is used to test materials havingcontents less than 0.001 % antimony, users of different labo-ratories will experience more than the usual 5 % risk that theirresults will differ by more than 50 % relative error.1.3 This
4、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 use.2. Referenced Documents2
5、.1 ASTM Standards:2E50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE 1184 Practice for Electrothermal (Graphite Furnace)Atomic Absorpt
6、ion AnalysisE 1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE 1770 Practice for Optimization of Electrothermal AtomicAbsorption Spectrometric EquipmentE 1806 Practice for Sampling Steel and Iron for Determi-nation of Chemical Composition2.2 I
7、SO Standards:3ISO 5725 Precision of Test MethodsDetermination ofRepeatability and Reproducibility for a Standard TestMethod by Inter-Laboratory TestsISO 10698 SteelDetermination of Antimony ContentElectrothermal Atomic Absorption Spectrometric Method3. Terminology3.1 For definitions of terms used in
8、 this test method, refer toTerminology E 135.4. Summary of Test Method4.1 The sample is dissolved in hydrochloric and nitric acidsand diluted to volume. An appropriate aliquot is injected intothe graphite furnace atomizer of an atomic absorption spec-trometer, which is equipped with a background cor
9、rection. Thesample is dried, pyrolized, and atomized. The absorbance ofthe radiation from the external light source is measured andcompared to the absorbance of samples of known concentra-tion.NOTE 1In general, the deuterium correction system should be able tocorrect for the broad-band background ab
10、sorbance up to 0.5 to 0.6absorbance units. Zeeman systems should compensate for backgroundlevels as high as 1.0 to 1.5 absorbance units.5. Significance and Use5.1 This test method is utilized for the determination oftrace levels of antimony in carbon and low-alloy steel. It isassumed that the proced
11、ure will be performed by trainedanalysts capable of performing common laboratory practicesskillfully and safely. It is expected that the work will be1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores and Related Materials and is the directrespon
12、sibility of Subcommittee E01.01 on Iron, Steel, and Ferroalloys.Current edition approved March 1, 2008. Published March 2008. Originallyapproved in 1996. Last previous edition approved in 2001 as E 1852 96 (2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cu
13、stomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM Inter
14、national, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.performed in a properly equipped laboratory and proper wastedisposal procedures will be followed.6. Apparatus6.1 Atomic Absorption Spectrometer with Graphite FurnaceAtomizer, equipped with background correc
15、tor and appropriatesignal output device, such as video display screen, digitalcomputer, printer or strip chart recorder, and autosampler. It isrecommended that the instrument meet the following perfor-mance requirements after adjusting the instrument and opti-mizing the furnace heating program as de
16、scribed in PracticeE 1770.6.1.1 The characteristic mass determined in accordancewith Practice E 1770 for antimony shall be less than 25 pg orwithin the manufacturers tolerance.6.1.2 The precision of the most concentrated blank additionsolution shall not exceed 10 % of the mean absorbance of thesame
17、solution. The precision of the least concentrated blankaddition solution (excluding Solution B0) shall not exceed 4 %of the mean absorbance of the most concentrated blankaddition solution when determined in accordance with PracticeE 1770.6.1.3 The limit of detection of antimony as described inPracti
18、ce E 1770 shall be less than 20 pg.6.1.4 Unless the instrument is provided with automaticcurve correction circuitry, the graph linearity shall not be lessthan 0.95 when determined in accordance with PracticeE 1770.6.2 Graphite Tubes, with pyrolytic coating and grooves forgraphite platform, suitable
19、for use with the graphite furnaceunit.6.3 Graphite Platform, pyrolytic graphite, Lvov design, tofit graphite tubes specified in 6.2.6.4 LabwareTo prevent contamination of the sample(s),all beakers, lids, volumetric flasks, and funnels must be cleanedwith hot HNO3(1 + 1) before use.7. Reagents7.1 Pur
20、ity and Concentration of ReagentsThe purity andconcentration of common chemical reagents shall conform toPractices E50. It is important that antimony shall not exceed0.01 g/mL in each of the reagents and 0.001 g/mL in thewater.7.2 Antimony Stock Solution (1 mL = 1 mg Sb)Dissolve0.1000 6 0.0001 g hig
21、h-purity antimony (minimum 99.9 %Sb) in 30 mL HCl + 5 mL HNO3in a 100-mL beaker. Boilgently to expel oxides of nitrogen. Cool and transfer thesolution into a 100-mL volumetric flask. Dilute to mark withHNO3(1 + 1) and mix. Store in polypropylene or high densitypolyethylene bottle.7.3 Antimony Standa
22、rd Solution (1 mL = 10 g Sb)Transfer 1.0 mL of the antimony stock solution to a 100-mLvolumetric flask, dilute to the mark with HNO3(1 + 1), andmix. Prepare this solution immediately before use.8. Sampling and Sample Preparation8.1 Refer to Practice E 1806 for devices and practices tosample liquid a
23、nd solid steel.8.2 The sampling procedures shall not involve any steps oroperations that can result in the loss of antimony in the sample.NOTE 2Arc melting of the sample or induction melting of the sampleunder vacuum may result in significant loss of several elements that havea low vapor pressure. A
24、rc melting of the sample should be avoided andinduction melting should be performed only in an at least partial inertatmosphere.8.3 The laboratory sample shall be cleaned by first washingin acetone and air drying.8.4 If brazed alloy tools are used in the preparation of thesample, the sample shall be
25、 further cleaned by pickling indiluted nitric acid for a few minutes. The sample shall then bewashed several times with water, then several times withacetone and air dried.9. Procedure9.1 Sample MassFor samples containing between0.0005 % and 0.0050 % antimony, the sample mass shall be1.00 g, weighed
26、 to the nearest 0.1 mg. For samples contain-ing between 0.0050 % and 0.010 % antimony, the sample shallbe 0.25 g weighed to the nearest 0.1 mg.9.2 BlankSimultaneously with the sample, a blank testusing the same quantities of all reagents shall be performed.The antimony contents of the blank should b
27、e no greater than10 ppb.9.3 Test SolutionTransfer the test portion in accordancewith 9.1 into a 250-mL beaker. Add 5 mL HCl and 50 mLHNO3. Cover the beaker with a watch glass, heat gently untilthe reaction ceases, and boil for 1 min to remove the oxides ofnitrogen.9.3.1 If sample contains tungsten o
28、r niobium, or both,transfer the test portion to a 100-mL beaker and add 1 mLH3PO4, 15 mLHCl, and 5 mLHNO3. Cover beaker with watchglass, and heat gently until reaction ceases. Evaporate thesolution to 2 mL to 3 mL; then add 25 mL nitric acid. Boil for1 min to remove oxides of nitrogen. Conduct a sep
29、arate blanktest corresponding to this procedure.9.3.2 Allow the solution, which may contain carbides, tocool. Add about 15 mL water, filter through medium texturefilter paper, and collect the filtrate in a 200-mL volumetricflask. Wash the filter paper several times with warm water andcollect the was
30、hings in the flask. Dilute to the mark with waterand mix.9.4 Test Addition SolutionsTransfer separate 20.0-mL ali-quot of the test solution into a series of five 100-mLvolumetricflasks. Using a micropipette, inject the respective volumes ofTABLE 1 Test Addition SolutionsName ofSolutionVolume ofAntim
31、onyStandardSolutionAdded, LConcentrationof AntimonyAdded in TestAdditionSolutions,ng/mLCorresponding Mass ofAntimony Added, ngVolumeInjected,10 LVolumeInjected,50 LS0000.0.S1100 10 0.1 0.5S2200 20 0.2 1.0S3400 40 0.4 2.0S4500 50 0.5 2.5E1852082antimony standard solution indicated in Table 1. Dilute
32、to themark with water and mix. These solutions are referred to as S0,S1,S2,S3, and S4, respectively.9.5 Blank Addition SolutionsTransfer separate 20.0-mLaliquots of the blank solution into a series of five 100-mLvolumetric flasks. Using a micropipette, add the respectivevolumes of antimony standard
33、solution indicated in Table 2.Dilute to the mark with water and mix. These solutions arereferred to as B0,B1,B2,B3, and B4, respectively.9.6 Optical parameters used for the determination of anti-mony are given in Table 3.9.7 The atomic absorption spectrometer and the graphitefurnace atomizer should
34、be adjusted and optimized as de-scribed in Practices E 1184 and E 1770.NOTE 3The volume injected into the atomizer should be between 10and 50 L, depending on sensitivity, matrix interference, backgroundcorrection, and range of linearity. The volume 20 L is usually correct.9.8 Using the autosampler,
35、inject the predetermined volumeof the test solution and blank addition solutions in increasingorder into the atomizer. Atomize each solution three times.Record the three peak height readings.NOTE 4In most instances, the use of peak area integration is prefer-able.9.9 Check the instrument for memory
36、effects, especially athigh analyte levels, by running the blank firing program. Resetthe baseline to zero if necessary. Record the peak heightreading for each determination (see Note 4).10. Plotting of Additions Graphs10.1 Calculate the average instrument readings for each ofthe blank addition solut
37、ions of 9.5 “B” against the mass ofantimony added, expressed in nanograms, in the blank additionsolutions.10.2 Calculate the average instrument readings for each ofthe test addition solutions of 9.5 “S” against the mass ofantimony added, expressed in nanograms, in the test additionsolutions.NOTE 5In
38、 this test method, any nonspecific absorption effect iseliminated by the background correction of the instrument.Antimony maybe present in the reagents. If antimony is present in the reagents, this plotmay not pass through the origin.10.3 The standard additions graphs for the blank and thesample sho
39、uld be parallel.11. Calculation11.1 Most graphite furnace atomizers controlled by comput-ers will calculate the means, establish their own calibrationcurves, and calculate and display the results. If using instru-ments not having this capability, prepare the calibrationsgraphs and perform the calibr
40、ation in accordance with 11.2 and11.3.11.2 Determine the mass of antimony in the test and blankaddition solutions, mSb.1and mSb.0, respectively, expressed innanograms, as the two intercepts on the mass axis by extrapo-lating the resulting straight lines in the two additions graphs(see 10.1 and 10.2)
41、. The difference (mSb.1 mSb.0) gives the netmass of antimony, mSb, in the test solution (Solution S1).11.2.1 The net mass of antimony, mSb, may also be calcu-lated using the least-square-fit method applied to the twostraight lines, the blank addition solutions (solutions “B”), andthe test addition s
42、olutions (solutions “S”). The equation of thestraight line relating absorbance to mass is as follows:y 5 a 1 bm (1)where:a and b = constants that correspond respectively to theintercept on the y axis and the slope of thestraight line. Calculate b and a using the least-square-fit method as follows:b
43、5 n(miyi2 (mi(yi#/n(mi2(mi!2# (2)a 5 1/n! (yi2 b(mi!The intercept on the x axis with the straight line of the slopeb is (a/b):mSb.15 1/nb1! (yi2 b1(mi! (3)mSb.05 1/nb0! (yi2 b0(mi!mSb5 mSb.12 mSb.0where:b = coefficient of regression;n = number of solutions analyzed;a = intercept on the y axis;mi= ma
44、ss of antimony added in the test or blankaddition solutions, ng;yi= absorbance corresponding to the test or blankaddition solutions;mSb.1= mass of the antimony obtained from the testaddition solutions, ng;mSb.0= mass of the antimony obtained from the blankaddition solutions, ng; andmSb= mass of anti
45、mony in the test addition solution (S0),ng.TABLE 2 Blank Addition SolutionsName ofSolutionVolume ofAntimonyStandardSolutionAdded, LConcentrationof AntimonyAdded in BlankAdditionSolutions,ng/mLCorresponding Mass ofAntimony Added, ngVolumeInjected,10 LVolumeInjected,50 LB0000.0.B1100 10 0.1 0.5B2200 2
46、0 0.2 1.0B3400 40 0.4 2.0B4500 50 0.5 2.5TABLE 3 Optical Parameters for Antimony DeterminationItem ParameterRadiation Source electrodeless discharge lamp (EDL) or hollow cathodelampLamp Current As recommended by lamp manufacturerSlit As recommended by instrument manufacturerWavelength 217.6 nmBackgr
47、ound Corrector yesE185208311.3 The antimony content, wSb, as a percentage by mass isobtained from the equation as follows:wSb5 100 mSb105V2/V1! V4/V3!#/109m (4)5 100 mSb105/V1! 200/20!#/109m 5 0.1 mSb/mV1where:V1= volume injected of a series of test addition solutionsand of the blank addition soluti
48、on (see Table 1 andTable 2), L;V2= volume of a series of test addition solutions and blankaddition solutions (see 9.4 and 9.5), mL;V3= volume of the aliquot of the test and blank solution(see 9.4 and 9.5), mL;V4= volume of the test and blank solutions (see 9.3.2),mL; andm = mass of the test portion
49、in 9.1,g.12. Precision and Bias12.1 PrecisionSixteen laboratories cooperated in testingthis method and obtained the statistical information summa-rized in Table 4 and Table 5.12.2 BiasThe accuracy of this test method at certainconcentration levels may be judged by comparing the acceptedreference values with the arithmetic average obtained byinterlaboratory testing (see Table 4 and Table 5).12.3 Interlaboratory Studies (ILS)4This test method wasevaluated by a working group within ISOTechnical Committee17 on Iron and Steel (ISO/TC 1
