1、Designation:D437406StandardTest Methods forCyanides in WaterAutomated Methods for Total Cyanide,Weak Acid Dissociable Cyanide,and Thiocyanate1This standard is issued under the fixed designation D4374;the number immediately following the designation indicates the year oforiginal adoption or,in the ca
2、se 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 These test methods cover the determination of differentspecies of cyanides and thiocyanate in wa
3、ter and waste water,namely weak acid dissociable cyanide,total cyanide,andthiocyanate(1).21.1.1 Total Cyanide This test method determines all theweak acid dissociable cyanides and the strong metal-cyano-complexes,such as ferrocyanide Fe(CN)64,ferricyanideFe(CN)63,hexacyanocolbaltate Co(CN)63,and tho
4、se ofgold and platinum.1.1.2 Weak Acid Dissociable CyanideThis test methodbasically determines free cyanides,as CNand HCN,andweak metal-cyano-complexes such as Cd(CN)42andMn(CN)63.Iron complexes are not included.1.1.3 Strong cyanide complexes,like those of iron,cobalt,etc.,can be determined by diffe
5、rence,that is,cyanide com-plexes=total cyanides weak acid dissociable cyanides.1.1.4 Thiocyanate This test method determines the thio-cyanate as the difference between another measurement thatincludes total cyanide plus thiocyanate and the value of totalcyanide,that is,thiocyanate=total cyanide plus
6、 thiocya-nate total cyanide.1.2 Cyanates and cyanogen halides are not detected.Cya-nogen chloride hydrolyzes to cyanate at the pH of samplepreservation(12).1.3 Most of the organo-cyano-complexes are not measured,with the exception of the weak cyanohydrins.1.4 These test methods apply to different ty
7、pes of water,waste water(raw sewage,sludge,and effluent),sludge,someindustrial waste,and sediments.Sample matrixes should beevaluated by the user.The reported precision and bias(seeSection 16)may not apply to all samples.1.5 The values stated in SI units are to be regarded as thestandard.1.6 This st
8、andard 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 specificprecautionary sta
9、tements,see Section 9.2.Referenced Documents2.1 ASTM Standards:3D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2036 Test Methods for Cyanides in WaterD3370 Practices for Sampling Water from Closed ConduitsD3864 Guide for Continual On-Line Monitoring Systemsfor Water Analysi
10、sD4193 Test Method for Thiocyanate in WaterD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD6696 Guide for Understanding Cyanide Species3.Terminology3.1 DefinitionsFor definition of terms relating to water,refer to Terminology D1129.3.1.1 For defi
11、nitions related to cyanide terminologies,referto Guide D6696.3.2 Definitions of Terms Specific to This Standard:3.2.1distillation ratio,%5volume of distilled portion of sampletotal volume of acidified sample31004.Summary of Test Method4.1 Some automated continuous flow modules are used(seeGuide D386
12、4)in addition to the newly developed on-line thinfilm distillation(2)and ultraviolet(UV)irradiation(3).1These test methods are under the jurisdiction of ASTM Committee D19 onWater and are the direct responsibility of Subcommittee D19.06 on Methods forAnalysis for Organic Substances in Water.Current
13、edition approved July 1,2006.Published July 2006.Originally approvedin 1984.Last previous edition approved in 2000 as D4374 00.DOI:10.1520/D4374-06.2The boldface numbers in parentheses refer to the list of references at the end ofthe text.3For referenced ASTM standards,visit the ASTM website,www.ast
14、m.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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesNOTICE:This standar
15、d has either been superseded and replaced by a new version or withdrawn.Contact ASTM International(www.astm.org)for the latest information14.2 Three factors control the separation of cyanides from thesamples,namely(a)UV irradiation,(b)pH and acidification,and(c)temperature and time of distillation(s
16、ee 7.4,7.5,and7.3).4.3 Acidification is made to pH 1 mg/L distills over with the cyanide causingnegative interference.Most samples do not contain mercury atthis high level.6.10 Potential Cyanide-Forming Materials:6.10.1 Several substances,namely cyanate,nitrobenzene,urea,thiourea,glycine,and cysteine,were investigated todetermine if they hydrolyze or break down under the experi-mental conditions and interfere with the cyanide determination.6.10.2 None of these materials gave interferences in the
