ASTM_E_1615_-_08.pdf

Designation:E161508Standard Test Method forIron in Trace Quantities Using the FerroZine Method1This standard is issued under the fixed designation E1615;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.Scope*1.1 This test method covers the determination of iron in therange from 0.01 to 0.2 g/g using FerroZine2reagent solution.The range may be extended through the use of a 5-or 10-cmcell or by suitable dilution of the sample solution.1.2 This test method is intended to be general for the finalsteps in the determination of iron and does not includeprocedures for sample preparation.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 Review the current material safety data sheets(MSDS)fordetailedinformationconcerningtoxicity,first-aidprocedures,and safety precautions.1.5 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 specificwarning statements,see 7.4.2.Referenced Documents2.1 ASTM Standards:3D1193 Specification for Reagent WaterE60 Practice for Analysis of Metals,Ores,and RelatedMaterials by SpectrophotometryE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)4E200 Practice for Preparation,Standardization,and Storageof Standard and Reagent Solutions for Chemical AnalysisE275 Practice for Describing and Measuring Performance ofUltraviolet and Visible Spectrophotometers3.Summary of Test Method3.1 This test method is based upon a photometric determi-nation of the FerroZine2complex with the iron(II)ion.5,6Thesample is dissolved in a suitable solvent and the iron is reactedwith FerroZine reagent solution which will convert the dis-solved iron compounds to form a magenta color iron(II)complex.The iron content of the sample solution is determinedby measurement of the magenta color at 560 nm using asuitable photometer.4.Significance and Use4.1 This test method is suitable for determining traceconcentrations of iron in a wide variety of products,providedthat appropriate sample preparation has rendered the iron andsample matrix soluble in water or other suitable solvent.Eachsample matrix must be investigated for suitability using thistest method.4.2 This test method assumes that the amount of colordeveloped is proportional to the amount of iron in the testsolution.The calibration curve is linear over the specifiedrange.5.Interferences5.1 Any ion that absorbs light at 560 nm will interfere withthe determination.Anionic interferences include oxalate inconcentrations over 500 g/g,cyanide,and nitrate.55.2 Of copper,cobalt,calcium,magnesium,lead,silver,molybdenum,aluminum,nickel,zinc,arsenic,manganese,hexavalent chromium,trivalent chromium,divalent cobalt andmonovalent copper are the only metals other than iron thatform colored species with FerroZine under test conditions.Atleast 1000 mg/L of the alkali metals and the alkaline earths hadno effect on the determination.Many heavy metals will react1This test method is under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicalsand is the direct responsibility of SubcommitteeE15.01 on General Standards.Current edition approved April 1,2008.Published May 2008.Originallyapproved in 1994.Last previous edition approved in 2005 as E161505.DOI:10.1520/E1615-08.2FerroZine is a trademark of Hach Chemical Company.3For 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.4The last approved version of this historical standard is referenced onwww.astm.org.5Stookey,L.L.,“FerroZineA New Spectrophotometric Reagent for Iron,”Analytical Chemistry,Vol 42,No.7,June 1970,pp.779 781.6Gibbs,C.R.,“Characterization and Application of FerroZine Iron Reagent asa Ferrous Iron Indicator,”Analytical Chemistry,Vol 48,No.8,July 1976,pp.11971201.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 with FerroZine in competition with iron,but with the excessreagent used in the test there is no effect on the results.55.3 The pH range of the final solution should be from 4 to9 to give the best test results.5,65.4 All glassware used in this test method must be iron-freeand scrupulously clean by precleaning with dilute hydrochloricacid and FerroZine reagent solution followe