ASTM_E_1917_-_13.pdf

Designation:E191713Standard Test Method forDetermination of Phosphorus in Nickel,Ferronickel,andNickel Alloys by PhosphovanadomolybdateSpectrophotometry1This standard is issued under the fixed designation E1917;the number immediately following the designation 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 determination of phospho-rus in nickel,ferronickel,and nickel alloys in the range0.0007%to 0.05%.1.2 Arsenic,chromium,hafnium,niobium,silicon,tantalum,titanium,and tungsten interfere,but the interferencecan be avoided by complexation or volatilization(for chro-mium).The lowest phosphorus content(0.0007%)can bereached only in samples with low contents of interferingelements.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 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 throughout this testmethod.2.Referenced Documents2.1 ASTM Standards:2E50 Practices for Apparatus,Reagents,and Safety Consid-erations for Chemical 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 Performance of an Analytical Method2.2 ISO Standards:3ISO 5725:1986 Precision of Test MethodsDeterminationof Repeatability and Reproducibility for a Standard TestMethod by Inter-laboratory TestsISO 11400:1992(E)Nickel,Ferronickel,andNickelAlloysDeterminationofPhosphorusContentPhosphovanadomolybdate Molecular Absorption Spectro-metric Method3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology E135.4.Summary 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 tophosphovanadomolybdic 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 nickel,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 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 E882.1This 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 Oct.1,2013.Published October 2013.Originallyapproved in 1997.Last previous edition approved in 2008 as E1917 08.DOI:10.1520/E1917-13.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Apparatus6.1 SpectrophotometerCapable of measuring absorbanceat a wavelength of 355 nm.6.2 CellsTo fit spectrophotometer,having an optical pathof 1 cm.NOTE1Cells 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 and 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 r