1、Designation: E1917 08E1917 13Standard Test Method forDetermination of Phosphorus in Nickel, Ferronickel, andNickel Alloys by Phosphovanadomolybdate MolecularAbsorption SpectrometrySpectrophotometry1This standard is issued under the fixed designation E1917; the number immediately following the design
2、ation indicates the year oforiginal adoption or, in the 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 test method covers the dete
3、rmination of phosphorus in nickel, ferronickel, and nickel alloys in the range 0.0007 % to0.05 %.1.2 Arsenic, chromium, hafnium, niobium, silicon, tantalum, titanium, and tungsten interfere, but the interference can beavoided by complexation or volatilization (for chromium). The lowest phosphorus co
4、ntent (0.0007 %) can be reached only insamples with low contents of interfering elements.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, ass
5、ociated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For specific hazards associated with the use of this test method see Practices E50. Refer to specific
6、 warningnotes given throughout this test method.2. Referenced Documents2.1 ASTM Standards:2E50 Practices forApparatus, Reagents, and Safety Considerations for ChemicalAnalysis of Metals, Ores, and Related MaterialsE135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materi
7、alsE882 Guide for Accountability and Quality Control in the Chemical Analysis LaboratoryE1601 Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method2.2 ISO Standards:3ISO 5725:1986 Precision of Test MethodsDetermination of Repeatability and Reproducibili
8、ty for a Standard Test Method byInter-laboratory TestsISO 11400:1992(E) Nickel, Ferronickel, and NickelAlloysDetermination of Phosphorus ContentPhosphovanadomolybdateMolecular Absorption Spectrometric Method3. Terminology3.1 DefinitionsFor definitions of terms used in this test method, refer to Term
9、inology E135.4. Summary of Test Method4.1 The sample is dissolved in a mixture of HCl and HNO3. HClO4 is added and the solution is evaporated to fumes of HClO4to remove chromium as volatile chromyl chloride. Silicon and refractory elements are complexed with fluoride ions through theaddition of HF.
10、Phosphorus is converted to phosphovanadomolybdic acid in an HClO4 and HNO3 solution. The phosphovana-domolybdic acid is extracted with 2-methyl-2-pentanone in the presence of citric acid to complex arsenic.Absorbance is measuredat 355 nm.1 This practice is under the jurisdiction of ASTM Committee E0
11、1 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility ofSubcommittee E01.08 on Ni and Co and High Temperature Alloys.Current edition approved Dec. 15, 2008Oct. 1, 2013. Published January 2009October 2013. Originally approved in 1997. Last previous edition
12、 approved in 20022008 asE1917 02.E1917 08. DOI: 10.1520/E1917-08.10.1520/E1917-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page
13、 on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the
14、 previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright AS
15、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Significance and Use5.1 This test method is used for the determination of phosphorus in nickel, ferronickel, and nickel alloy samples by molecularabsorption spectrometry to check compliance with
16、compositional specifications. It is assumed that all who use the procedure willbe trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that the work will beperformed in a properly equipped laboratory and that proper waste disposal procedures will
17、be followed. Appropriate qualitycontrol practices must be followed, such as those described in Guide E882.6. Apparatus6.1 SpectrophotometerCapable of measuring absorbance at a wavelength of 355 nm.6.2 CellsTo fit spectrophotometer, having an optical path of 1 cm.NOTE 1Cells having other dimensions c
18、an be used, provided suitable adjustments can be made in the amount of sample and reagents used.6.3 Plastic separatory funnels, 250-mL capacity.7. Reagents7.1 Purity and Concentration of ReagentsThe purity and concentration of common chemical reagents and water shall conformto Practices E50. The rea
19、gents should be free of or contain only minimal amounts ( 0.1 g/g) of phosphorus.7.1.1 Verify the absence of phosphorus in the reagents using the blank test. Reagents giving high blank values are unsuitableand should not be used. The blank value for all reagents should be below 0.0005 % P calculated
20、 for a 1-g sample.7.2 Ammonium Metavanadate SolutionDissolve 2.5 g of ammonium metavanadate (NH4VO3) in water, dilute to 1 L, and mix.7.3 Citric Acid SolutionDissolve 500 g citric acid monohydrate (C6H8 O7H2O) in water, dilute to 1 L, and mix. Warm thesolution if necessary to facilitate dissolution.
21、7.4 Fluoroboric Acid SolutionDisperse 75 g of boric acid (H3BO3) in 600 mL of hot water in a plastic beaker. Add 50 mL ofHF (40 %) and dilute to 1 L. Digest over medium heat until the boric acid is dissolved. Store in a plastic bottle. The solution shouldbe heated gently if the boric acid forms crys
22、tals. (WarningHF and fluoroboric acid are extremely irritating and corrosive to skinand mucous membranes, producing severe skin burns that are slow to heal. In case of contact with skin, wash well with water andseek medical advice. When using HF and fluoroboric acid, always wear appropriate safety g
23、ear, such as goggles and gloves.)7.5 Hexaammonium Heptamolybdate SolutionDissolve 15 g of hexaammonium heptamolybdate tetrahydrate(NH4)6Mo7O244H2O in warm water and dilute to 100 mL. Prepare fresh solution each day. If high and unstable blank valuesappear, there might be a problem with the salt used
24、. In such a case, switch to another lot.7.6 4-Methyl-2-pentanoneMethylisobutyl ketone.7.7 Phosphorus Stock Calibration Solution (1.000 g/L)Transfer 4.3942 g of potassium dihydrogenorthophosphate (KH2PO4)(which has been previously dried at 110 C to constant weight and cooled in a desiccator) to a 1-L
25、 volumetric flask. Dissolve inwater, dilute to the mark, and mix.7.8 Phosphorus Calibration Solution (10 mg/L)Transfer 10.0 mL of the phosphorus stock calibration solution to a 1-Lvolumetric flask. Dilute to the mark and mix.7.9 Sodium Nitrite Solution (50 g/L)Dissolve 50 g of sodium nitrite (NaNO2)
26、 in water and dilute to 1 L.8. Sampling and Sample Preparation8.1 The sampling shall be performed by normal procedures agreed upon between the parties, or in the event of a dispute, inaccordance with the relevant standard, if one is available.8.2 The laboratory sample is normally in the form of mill
27、ings or drillings and no further preparation of the sample is necessary.8.3 If it is suspected that the laboratory sample is contaminated with oil or grease from the milling or drilling operation, it shallbe cleaned by washing it with high purity acetone, or other appropriate solvent, and dried in a
28、ir.8.4 If the sample contains particles or pieces of widely varying sizes, the test sample should be obtained by riffling.TABLE 1 Weight of Test Portion of the SampleExpectedPhosphorusContent, %Weight of TestPortion, gMaximum concentration of the interferingelements, %As Hf Nb Ta Ti W0.0005 to 0.010
29、 1.0 0.05 0.1 1 0.1 2 20.002 to 0.04 0.25 0.2 0.5 5 0.5 10 80.005 to 0.050 0.10 0.5 1.5 10 1 25 25E1917 1329. Procedure9.1 Test Portion and Preparation of Test Solution:9.1.1 Weigh to the nearest 0.1 mg a test portion of the sample in accordance with Table 1.9.1.2 Transfer the test portion to a poly
30、tetrafluoroethylene (PTFE) beaker and add 5 mL of HNO3 and then 5 mL of HCl. Forsamples with high contents of niobium, silicon, tantalum, or hafnium, also add 7 mL of HF. Cover the beaker with a PTFE coverand heat gently until the reaction ceases. Use a sandbath or other means to avoid direct contac
31、t of the PTFE beaker with a metalhotplate surface. Add 10 mL of HClO4 and, leaving a small opening to release the vapors, evaporate to dense HClO4 fumes.(WarningFuming HClO4 is a powerful oxidant and can cause explosions when in contact with organic materials. Allevaporations must be performed in th
32、e presence of HNO3 and in a fume hood specifically designed for use with HClO4.)NOTE 2Nickel and some copper bearing nickel alloys, such as Monel, will dissolve more readily in HNO3 (1 + 1).9.1.3 For samples containing less than 0.1 % chromium, omit the next step and proceed directly to 9.3.9.2 Remo
33、val of Chromium:9.2.1 Continue fuming for 3 min. Cautiously begin adding HCl drop by drop to the fuming solution in the partly covered beakeruntil colored fumes are no longer liberated. Then resume fuming to re-oxidize the remaining chromium. Repeat the treatment untilno brown fumes appear when the
34、HCl is added. Cool to room temperature.9.3 Complexation:9.3.1 Add 25 mLof HNO3 (1 + 4) and 4 mLof HF to the solution and heat for 8 min to 10 min until the precipitate is dissolved.NOTE 3It is important that the precipitated refractory oxides dissolve completely. If this does not happen, add another
35、 2 mL of HF and repeat theboiling. If the precipitate still remains undissolved, a new test sample of a smaller weight must be taken for the analysis.TABLE 2 Nominal Composition of Nickel and Ferro-nickelSamples, %Test Material P As Cr Fe Si NiNi #1 0.00005 - - 0.01 - balanceNi #2 0.0008 - - balance
36、 - balanceFe-Ni #1 0.01 0.001 0.5 balance 0.5 25Fe-Ni #2 0.01 0.1 4.5 balance 5 25Fe-Ni #3 0.045 0.001 0.5 balance 0.6 25Fe-Ni #4 0.045 0.1 4.5 balance 5 25TABLE 3 Nominal Composition of Nickel Alloy Samples, %Sample P Co Cr Cu Fe Mo Ni Nb W4D-7 0.01 - - 32 1 - 65 - -4D-8 0.01 - 21 - 4 9 62 3 -4D-9
37、0.02 - 19 - 19 3 53 5 -4D-10 0.02 - 20 - 46 - 31 - -4D-11 0.01 - 21 - 20 8 47 - -4D-12A 0.005 42 21 - 2 4 20 4 4A Standard Reference alloy BAM 328-1, certified at 0.005 % P was used assample 4D-12.TABLE 4 Results of Statistical AnalysisTestMaterialAMean,%RepeatabilityIndex (PracticeE1601)Reproducibi
38、lityIndex (PracticeE1601)Ni #2 0.00091 0.0002 0.00044D-12B 0.0054 0.0004 0.00224D-8 0.0089 0.0024 0.0050FeNi #1 0.0100 0.0012 0.0014FeNi #2 0.0100 0.0012 0.00124D-7 0.0120 0.0016 0.00264D-11 0.0135 0.0016 0.00274D-9 0.0148 0.0023 0.00284D-10 0.0185 0.0010 0.0022FeNi #4 0.0425 0.0027 0.0038FeNi #3 0.
39、0437 0.0021 0.0068A Material compositions are summarized in Table 2 and Table 3.B Standard Reference alloy BAM 328-1, certified at 0.005 % P was used assample 4D-12.E1917 1339.3.2 Add 10 mL of sodium nitrite solution and boil the solution for 10 min to reduce the residual dichromate and expel allnit
40、rous fumes. Cautiously wash the beaker walls a few times with water during boiling.9.3.3 Add 40 mL of fluoroboric acid solution and rapidly cool the solution to between 20 C and 30 C, and proceedimmediately with the color development.NOTE 4The oxides might precipitate again if it required more than
41、10 min to cool the solution.9.4 Color Development and Extraction:9.4.1 Add 10 mL of the ammonium metavanadate solution and 15 mL of the hexaammonium heptamolybdate solution to thecooled clear solution. Allow to stand at a temperature between 18 C and 25 C for a minimum of 7 min, but not longer than
42、15min.9.4.2 Transfer the solution to a 250-mL plastic separatory funnel that has been marked at the 100-mL level and, if necessary,make up to the mark with water. Add 10 mL of citric acid solution and immediately follow with 40 mL of 4-methyl-2-pentanone.Shake the funnel for 30 s. Allow the two laye
43、rs to separate and discard the lower (aqueous) phase. Dry the inside of the stem ofthe separatory funnel with a small piece of filter paper. Filter the organic layer through a dry filter paper into a small dry beaker.Proceed immediately with the spectrometric measurement.9.5 Spectrometric Measuremen
44、t:9.5.1 Ensure that the temperature of the solutions is constant to 6 1 C. Measure the absorbance of the solution with aspectrophotometer at a wavelength of 355 nm. Use 4-methyl-2-pentanone as the reference and cells with a 1 cm optical path length.9.6 Blank Test:9.6.1 Perform a blank test in parall
45、el with the determination following the same procedure and using the same quantities ofreagents as in the determination, but omitting the test portion.9.7 Calibration:9.7.1 Transfer (0, 2.5, 5.0, and 10.0) mL, respectively, of the phosphorus calibration solution to four plastic beakers. Theadditions
46、 correspond to (0, 0.025, 0.050, and 0.100) mg of phosphorus. Proceed as directed in 9.1.2 9.5.1, but do not add anytest portions.9.7.2 Subtract the absorbance of the “zero” solution from that of each solution containing phosphorus, and plot the absorbanceagainst the weight, in milligrams, of phosph
47、orus added.9.8 Number of Determinations:9.8.1 Perform the determinations at least in duplicate.10. Calculation10.1 Correct the absorbance reading of the test solution by subtracting the absorbance reading in the blank test. Convert the netabsorbance of the test solution into mg of phosphorus by mean
48、s of the calibration graph.10.2 Calculate the percentage by weight of phosphorus in the test sample using the formula:%P 5A/10B (1)where:A = the weight, mg, of phosphorus found in the test portion, andB = the weight, g, of the test portion.11. Precision and Bias411.1 PrecisionEight laboratories in s
49、ix countries cooperated in the testing of this test method under the auspices ofISO/TC155/SC4 in the late 1980s and published as ISO 11400:1992(E). Two samples of nickel metal, four samples of ferronickel,and six samples of nickel based alloys as described in Table 2 and Table 3 were used to obtain the statistical information, asevaluated by ISO 5725:1986 and equivalent to Practice E1601, summarized in Table 4.11.2 BiasNo information on the accuracy of this test method is known because only one accepted reference standard was usedin the int
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