ASTM_D_3867_-_16.pdf

Designation:D386716Standard Test Methods forNitrite-Nitrate in Water1This standard is issued under the fixed designation D3867;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 These test methods cover the determination of nitritenitrogen,nitrate nitrogen,and combined nitrite-nitrate nitrogenin water and wastewater in the range from 0.05 to 1.0 mg/Lnitrogen.Two test methods2are given as follows:SectionsTest Method AAutomated Cadmium Reduction9 to 18Test Method BManual Cadmium Reduction19 to 281.2 These test methods are applicable to surface,saline,waste,and ground waters.It is the users responsibility toensure the validity of these test methods for waters of untestedmatrices.1.3 The values stated in either SI or inch-pound units are tobe regarded as the standard.No other units of measurement areincluded in this standard.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 hazardstatements,see Notes 1 and 2.2.Referenced Documents2.1 ASTM Standards:3D1129 Terminology Relating to WaterD1141 Practice for the Preparation of Substitute OceanWaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD7781 Test Method for Nitrite-Nitrate in Water by NitrateReductaseE60 Practice for Analysis of Metals,Ores,and RelatedMaterials by SpectrophotometryE275 Practice for Describing and Measuring Performance ofUltraviolet and Visible Spectrophotometers3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in these test standards,refer to Terminology D1129.4.Summary of Test Methods4.1 Total Oxidized Nitrogena filtered sample is passedthrough a column containing copper-coated cadmium granulesto reduce nitrate ion to nitrite ion.The combined nitrite-nitratenitrogen is determined by diazotizing the total nitrite ion withsulfanilamideandcouplingwithN-(1-naphthyl)ethylenediamine dihydrochloride to form a highlycolored azo dye that is measured spectrophotometrically.4.2 Nitritethe nitrite ion originally present in the samplecan be determined separately by carrying out the procedure andomitting the cadmium reduction step.4.3 Nitratethe nitrate ion can be calculated as the differ-ence between the combined nitrite-nitrate nitrogen and thenitrite nitrogen.5.Significance and Use5.1 Both test methods use identical reagents and sampleprocessing.The only difference between the two methods isthat one test method is automated and the other is manual.Theranges and interferences are identical.5.2 The automated test method is preferred when largenumbers of samples are to be analyzed.The manual testmethod is used for fewer samples or when automated instru-mentation is not available.5.3 These test methods replace Test Methods D1254(Ni-trite)and D992(Nitrate).The nitrite test method(Test MethodD1254)used a reagent that is considered to be a potentialcarcinogen.The nitrate test method(Test Method D992)has1These test methods are under the jurisdiction of ASTM Committee D19 onWater and are the responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved June 1,2016.Published June 2016.Originallyapproved in 1979.Last previous edition approved in 2009 as D3867 09.DOI:10.1520/D3867-16.2Methods similar to these appear in Methods of Chemical Analysis of Water andWastes,2nd edition,U.S.Environmental Protection Agency.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.*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 been shown to have relatively large errors when used inwastewaters and also has greater manipulative difficulties thanthe test method described herein.5.4 Test Method D7781 uses a nitrate reductase enzyme forthe reduction of nitrate to nitrite.Cadmium is considered atoxic metal.Also,the heterogeneous cadmium reductant cre-ates greater difficulty than the reduction described in this testmethod.6.Interferences6.1 Turbid samples must be filtered prior to analysis toeliminate particulate interference.Furthermore,sample turbid-ity