1、Designation: E 1917 08Standard Test Method forDetermination of Phosphorus in Nickel, Ferronickel, andNickel Alloys by Phosphovanadomolybdate MolecularAbsorption Spectrometry1This standard is issued under the fixed designation E 1917; the number immediately following the designation indicates the yea
2、r 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 determination of phospho-ru
3、s in nickel, ferronickel, and nickel alloys in the range0.0007 % to 0.05 %.1.2 Arsenic, chromium, hafnium, niobium, silicon, tanta-lum, titanium, and tungsten interfere, but the interference canbe avoided by complexation or volatilization (for chromium).The lowest phosphorus content (0.0007 %) can b
4、e reached onlyin samples with low contents of interfering elements.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It
5、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. For specific hazardsassociated with the use of this test method see Practices E50.Refer to specific warning notes given thr
6、oughout this testmethod.2. Referenced Documents2.1 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 882 Guide for Acc
7、ountability and Quality Control in theChemical Analysis LaboratoryE 1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical Method2.2 ISO Standards:3ISO 5725:1986 Precision of Test MethodsDeterminationof Repeatability and Reproducibility for a Standard TestM
8、ethod by Inter-laboratory TestsISO 11400:1992(E) Nickel, Ferronickel, and NickelAlloysDetermination of Phosphorus ContentPhosphovanadomolybdate Molecular Absorption Spectro-metric Method3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology E 135.4. Summa
9、ry of Test Method4.1 The sample is dissolved in a mixture of HCl and HNO3.HClO4is added and the solution is evaporated to fumes ofHClO4to remove chromium as volatile chromyl chloride.Silicon and refractory elements are complexed with fluorideions through the addition of HF. Phosphorus is converted t
10、ophosphovanadomolybdic acid in an HClO4and HNO3solution.The phosphovanadomolybdic acid is extracted with 2-methyl-2-pentanone in the presence of citric acid to complex arsenic.Absorbance is measured at 355 nm.5. Significance and Use5.1 This test method is used for the determination ofphosphorus in n
11、ickel, ferronickel, and nickel alloy samples bymolecular absorption spectrometry to check compliance withcompositional specifications. It is assumed that all who use theprocedure will be trained analysts capable of performingcommon laboratory procedures skillfully and safely. It isexpected that the
12、work will be performed in a properlyequipped laboratory and that proper waste disposal procedureswill be followed. Appropriate quality control practices must befollowed, such as those described in Guide E 882.6. Apparatus6.1 SpectrophotometerCapable of measuring absorbanceat a wavelength of 355 nm.1
13、This practice is under the jurisdiction of ASTM Committee E01 on AnalyticalChemistry 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, 2008. Published January 2009. Originallyappro
14、ved in 1997. Last previous edition approved in 2002 as E 1917 02.2For 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 webs
15、ite.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 CellsTo fit spectrophotometer, having an optical p
16、athof 1 cm.NOTE 1Cells having other dimensions can be used, provided suitableadjustments 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 andconcentration of common chemical reagents an
17、d water shallconform to Practices E50. The reagents should be free of orcontain only minimal amounts ( 0.1 g/g) of phosphorus.7.1.1 Verify the absence of phosphorus in the reagents usingthe blank test. Reagents giving high blank values are unsuitableand should not be used. The blank value for all re
18、agents shouldbe below 0.0005 % P calculated for a 1-g sample.7.2 Ammonium Metavanadate SolutionDissolve 2.5 g ofammonium metavanadate (NH4VO3) in water, dilute to 1 L,and mix.7.3 Citric Acid SolutionDissolve 500 g citric acid mono-hydrate (C6H8O7H2O) in water, dilute to 1 L, and mix. Warmthe solutio
19、n if necessary to facilitate dissolution.7.4 Fluoroboric Acid SolutionDisperse 75 g of boric acid(H3BO3) in 600 mLof hot water in a plastic beaker.Add 50 mLof HF (40 %) and dilute to 1 L. Digest over medium heat untilthe boric acid is dissolved. Store in a plastic bottle. Thesolution should be heate
20、d gently if the boric acid formscrystals. (WarningHF and fluoroboric acid are extremelyirritating and corrosive to skin and mucous membranes, pro-ducing severe skin burns that are slow to heal. In case ofcontact with skin, wash well with water and seek medicaladvice. When using HF and fluoroboric ac
21、id, always wearappropriate safety gear, such as goggles and gloves.)7.5 Hexaammonium Heptamolybdate SolutionDissolve15 g of hexaammonium heptamolybdate tetrahydrate(NH4)6Mo7O244H2O in warm water and dilute to 100 mL.Prepare fresh solution each day. If high and unstable blankvalues appear, there migh
22、t be a problem with the salt used. Insuch 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 toconstant weight and c
23、ooled in a desiccator) to a 1-L volumetricflask. Dissolve in water, dilute to the mark, and mix.7.8 Phosphorus Calibration Solution (10 mg/L)Transfer10.0 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
24、50 g ofsodium nitrite (NaNO2) in water and dilute to 1 L.8. Sampling and Sample Preparation8.1 The sampling shall be performed by normal proceduresagreed upon between the parties, or in the event of a dispute,in accordance with the relevant standard, if one is available.8.2 The laboratory sample is
25、normally in the form ofmillings or drillings and no further preparation of the sample isnecessary.8.3 If it is suspected that the laboratory sample is contami-nated with oil or grease from the milling or drilling operation,it shall be cleaned by washing it with high purity acetone, orother appropria
26、te solvent, and dried in air.8.4 If the sample contains particles or pieces of widelyvarying sizes, the test sample should be obtained by riffling.9. Procedure9.1 Test Portion and Preparation of Test Solution:9.1.1 Weigh to the nearest 0.1 mg a test portion of thesample in accordance with Table 1.9.
27、1.2 Transfer the test portion to a polytetrafluoroethylene(PTFE) beaker and add 5 mL of HNO3and then 5 mL of HCl.For samples with high contents of niobium, silicon, tantalum,or hafnium, also add 7 mL of HF. Cover the beaker with aPTFE cover and heat gently until the reaction ceases. Use asandbath or
28、 other means to avoid direct contact of the PTFETABLE 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 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
29、 0.10 0.5 1.5 10 1 25 25TABLE 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 - 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
30、 #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 0.02 - 19 - 19 3 53 5 -4D-10 0.02 - 20 - 46 - 31 - -4D-11 0.01 - 21 - 20 8 47 - -4D-12A0.005 42 21 - 2 4 20 4 4AStandard Refer
31、ence alloy BAM 328-1, certified at 0.005 % P was used assample 4D-12.TABLE 4 Results of Statistical AnalysisTestMaterialAMean,%RepeatabilityIndex (PracticeE 1601)ReproducibilityIndex (PracticeE 1601)Ni #2 0.00091 0.0002 0.00044D-12B0.0054 0.0004 0.00224D-8 0.0089 0.0024 0.0050FeNi #1 0.0100 0.0012 0
32、.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 0.0437 0.0021 0.0068AMaterial compositions are summarized in Table 2 and Table 3.BStandard Reference alloy BAM 328-1, certified a
33、t 0.005 % P was used assample 4D-12.E1917082beaker with a metal hotplate surface. Add 10 mL of HClO4and, leaving a small opening to release the vapors, evaporate todense HClO4fumes. (WarningFuming HClO4is a powerfuloxidant and can cause explosions when in contact with organicmaterials. All evaporati
34、ons must be performed in the presenceof HNO3and in a fume hood specifically designed for use withHClO4.)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 dir
35、ectly to 9.3.9.2 Removal of Chromium:9.2.1 Continue fuming for 3 min. Cautiously begin addingHCl drop by drop to the fuming solution in the partly coveredbeaker until colored fumes are no longer liberated. Thenresume fuming to re-oxidize the remaining chromium. Repeatthe treatment until no brown fum
36、es appear when the HCl isadded. Cool to room temperature.9.3 Complexation:9.3.1 Add 25 mL of HNO3(1 + 4) and 4 mL of HF to thesolution and heat for 8 min to 10 min until the precipitate isdissolved.NOTE 3It is important that the precipitated refractory oxides dissolvecompletely. If this does not hap
37、pen, add another 2 mLof HF and repeat theboiling. If the precipitate still remains undissolved, a new test sample ofa smaller weight must be taken for the analysis.9.3.2 Add 10 mL of sodium nitrite solution and boil thesolution for 10 min to reduce the residual dichromate and expelall nitrous fumes.
38、 Cautiously wash the beaker walls a few timeswith water during boiling.9.3.3 Add 40 mL of fluoroboric acid solution and rapidlycool 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 10min to cool
39、 the solution.9.4 Color Development and Extraction:9.4.1 Add 10 mL of the ammonium metavanadate solutionand 15 mL of the hexaammonium heptamolybdate solution tothe cooled clear solution. Allow to stand at a temperaturebetween 18 C and 25 C for a minimum of 7 min, but notlonger than 15 min.9.4.2 Tran
40、sfer the solution to a 250-mL plastic separatoryfunnel that has been marked at the 100-mL level and, ifnecessary, make up to the mark with water.Add 10 mL of citricacid solution and immediately follow with 40 mL of 4-methyl-2-pentanone. Shake the funnel for 30 s.Allow the two layers toseparate and d
41、iscard the lower (aqueous) phase. Dry the insideof the stem of the separatory funnel with a small piece of filterpaper. Filter the organic layer through a dry filter paper into asmall dry beaker. Proceed immediately with the spectrometricmeasurement.9.5 Spectrometric Measurement:9.5.1 Ensure that th
42、e temperature of the solutions is constantto 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 pathlength.9.6 Blank Test:9.6.1 Perform a blank test in parallel with the determinatio
43、nfollowing 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 thephosphorus calibration solution to four plastic beakers. Theadditions correspond to (0, 0.025,
44、0.050, and 0.100) mg ofphosphorus. Proceed as directed in 9.1.2-9.5.1, but do not addany test portions.9.7.2 Subtract the absorbance of the “zero” solution fromthat of each solution containing phosphorus, and plot theabsorbance against the weight, in milligrams, of phosphorusadded.9.8 Number of Dete
45、rminations:9.8.1 Perform the determinations at least in duplicate.10. Calculation10.1 Correct the absorbance reading of the test solution bysubtracting the absorbance reading in the blank test. Convertthe net absorbance of the test solution into mg of phosphorusby means of the calibration graph.10.2
46、 Calculate the percentage by weight of phosphorus inthe test sample using the formula:% P 5 A/10B (1)where:A = the weight, mg, of phosphorus found in the testportion, andB = the weight, g, of the test portion.11. Precision and Bias411.1 PrecisionEight laboratories in six countries cooper-ated in the
47、 testing of this test method under the auspices ofISO/TC155/SC4 in the late 1980s and published asISO 11400:1992(E). Two samples of nickel metal, foursamples of ferronickel, and six samples of nickel based alloysas described in Table 2 and Table 3 were used to obtain thestatistical information, as e
48、valuated by ISO 5725:1986 andequivalent to Practice E 1601, summarized in Table 4.11.2 BiasNo information on the accuracy of this testmethod is known because only one accepted reference standardwas used in the interlaboratory study. The user of this testmethod is encouraged to employ accepted refere
49、nce materials,if available, to determine the accuracy of this test method as itapplies in a specific laboratory.4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: E01-1021.E191708312. Keywords12.1 ferronickel; molecular absorption spectrometry; nickel;nickel alloy; phosphorus content; spectrophotometricASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are express
