ASTM D2036-2006 Standard Test Methods for Cyanides in Water《水中氰化物的标准测试方法》.pdf

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1、Designation: D 2036 06Standard Test Methods forCyanides in Water1This standard is issued under the fixed designation D 2036; 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 indicat

2、es the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover the determination of cyanidesin water. The following test

3、 methods are included:SectionsTest Method ATotal Cyanides after Distillation 12 to 18Test Method BCyanides Amenable to Chlorination2by Difference 19 to 25Test Method CWeak Acid Dissociable Cyanides 26 to 32Test Method DCyanides Amenable to Chlorination without Distilla-tion (Short-Cut Method)33 to 3

4、91.2 Cyanogen halides may be determined separately.NOTE 1Cyanogen chloride is the most common of the cyanogenhalide complexes as it is a reaction product and is usually present whenchlorinating cyanide-containing industrial waste water. For the presenceor absence of CNCl, the spot test method given

5、in Annex A1 can be used.1.3 These test methods do not distinguish between cyanideions and metallocyanide compounds and complexes. Further-more, they do not detect the cyanates.NOTE 2The cyanate complexes are decomposed when the sample isacidified in the distillation procedure.1.4 The cyanide in cyan

6、ocomplexes of gold, platinum,cobalt and some other transition metals is not completelyrecovered by these test methods.1.5 Cyanide from only a few organic cyanides are recov-ered, and those only to a minor extent.1.6 Part or all of these test methods have been usedsuccessfully with reagent water and

7、various waste waters. It isthe users responsibility to assure the validity of the testmethod for the water matrix being tested.1.7 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 a

8、ppro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardstatements are given in sections 5.1, 8.8, 8.18, 9, 11.2, and16.1.9.2. Referenced Documents2.1 ASTM Standards:3D 1129 Terminology Relating to WaterD 1193 Specification for

9、Reagent WaterD 2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD 3370 Practices for Sampling Water from Closed ConduitsD 5788 Guide for Spiking Organics into Aqueous SamplesD 5847 Practice for Writing Quality Control Specificationsfor Standard

10、 Test Methods for Water AnalysisD 6696 Guide for Understanding Cyanide SpeciesD 6888 Test Method for Available Cyanide with LigandDisplacement and Flow Injection Analysis (FIA) UtilizingGas Diffusion Separation and Amperometric DetectionE60 Practice for Analysis of Metals, Ores, and RelatedMaterials

11、 by Molecular Absorption SpectrometryE 275 Practice for Describing and Measuring Performanceof Ultraviolet, Visible, and Near-Infrared Spectrophotom-eters3. Terminology3.1 DefinitionsFor definitions of terms used in these testmethods, refer to Terminology D 1129 and Guide D 6696.3.2 Abbreviations: A

12、bbreviations:3.2.1 HPLCHigh Performance Liquid Chromatography3.2.2 ICIon Chromatography4. Summary of Test Methods4.1 The cyanide as hydrocyanic acid (HCN) is releasedfrom compounds by means of reflux distillation and absorbedin sodium hydroxide solution. The conditions used for thedistillation disti

13、nguish the type of cyanide. The sodium cyanide1These 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 edition approved Feb. 15, 2006. Published February 2006.

14、Originallyapproved in 1964. Last previous edition approved in 1998 as D 2036 98.2For an explanation of the term cyanides amenable to alkaline chlorination, seeLancy, L. E. and Zabban, W., “Analytical Methods and Instrumentation forDetermining Cyanogen Compounds,” Papers on Industrial Water and Indus

15、trialWaste Water, ASTM STP 337, 1962, pp. 3245.3For 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.1Copyright AST

16、M International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.in the absorbing solution can be determined colorimetrically,by titration or by selective ion electrode.4.2 Test Method A, Total Cyanides, is based on the decom-position of nearly all cyanides in the

17、 presence of strong acid,magnesium chloride catalyst, and heat during a 1-h refluxdistillation.4.3 Test Method B, Cyanide Amenable to Chlorination, isbased on chlorinating a portion of the sample under controlledconditions followed by the determination of total cyanide inboth the original and chlori

18、nated samples. Cyanides amenableto chlorination are calculated by difference.4.3.1 This test method can be affected by compounds thatare converted during chlorination to color-producing com-pounds or react with the reagents used, and cause interferencein the procedure employed to determine cyanide i

19、n the absorp-tion solution.4.4 Test Method C, Weak Acid Dissociable Cyanides, isbased on the decomposition of cyanides in the presence ofweak acid, zinc acetate and heat during a 1-h reflux distillation.4.5 Test Method D, Cyanide Amenable to Chlorinationwithout Distillation, is a direct colorimetric

20、 procedure.4.6 The minimum concentration of cyanide in the absorp-tion solution that can be accurately determined colorimetricallyis 0.005 mg/L, by titration 0.4 mg/L and by selective ionelectrode 0.05 mg/L. Pretreatment including distillation tendsto increase these concentrations to a degree determ

21、ined by theamount of manipulation required and the type of sample.4.7 Round-robin data indicate the following minimum con-centrations: colorimetric 0.03 mg/L; titration 1.0 mg/L; andselective ion electrode 0.03 mg/L.5. Significance and Use5.1 Cyanide is highly toxic. Regulations have been estab-lish

22、ed to require the monitoring of cyanide in industrial anddomestic wastes and in surface waters (Appendix X1).5.2 Test Method D is applicable for natural water and cleanmetal finishing or heat treatment effluents. It may be used forprocess control in wastewater treatment facilities providing itsappli

23、cability has been validated by Test Method B or C.5.3 The spot test outlined inAnnexA1 can be used to detectcyanide and thiocyanate in water or wastewater, and toapproximate its concentration.6. Interferences6.1 Common interferences in the analysis for cyanide in-clude oxidizing agents, sulfides, al

24、dehydes, glucose and othersugars, high concentration of carbonate, fatty acids, thiocyan-ate, and other sulfur containing compounds.6.2 It is beyond the scope of these test methods to describeprocedures for overcoming all of the possible interferences thatmay be encountered.6.3 Separation of the cya

25、nide from interfering substancesprior to electrochemical determination (see 16.5 for ion chro-matography procedure) should be conducted when using TestMethod A-total cyanides after distillation or Test MethodB-cyanides amenable to chlorination by the difference whensulfur, thiocyanate, or other sulf

26、ur containing compounds arepresent.6.4 When the procedures must be revised to meet specificrequirements, recovery data must be obtained by the additionof known amounts of cyanide to the sample.7. Apparatus7.1 Distillation ApparatusThe reaction vessel shall be a1-L round bottom flask, with provision

27、for an inlet tube and acondenser. The inlet tube shall be a funnel with an 8-mmdiameter stem that extends to within 6 mm of the bottom of theflask. The condenser, which is recommended, shall be areflux-type, cold finger, or Allihn. The condenser shall beconnected to a vacuum-type absorber which shal

28、l be in turnconnected to a vacuum line which has provision for finecontrol. The flask shall be heated with an electric heater.Examples of the apparatus are shown in Fig. 1. Equivalentapparatus is acceptable provided cyanide recoveries of 100 64 % are documented.7.1.1 Smaller distillation tubes such

29、as 50-mL MIDI tubescan be used if the quality control requirements in Section 40are satisfied. The reagents should be added proportionately tothose specified in this test method for smaller sample sizes.While the use of smaller distillation tubes is generally ac-cepted, the interlaboratory study was

30、 conducted with 500-mLsamples; therefore, the user is responsible to determine theactual precision and bias when using a different type ofdistillation apparatus.7.2 Spectrophotometer or Filter Photometer, suitable formeasurement in the region of 578 nm, using 1.0-, 2.0-, 5.0-,and 10.0-cm absorption

31、cells. Filter photometers and photo-metric practices used in these test methods shall conform toPractice E60. Spectrophotometers shall conform to PracticeE 275.FIG. 1 Cyanide Distillation ApparatusD20360627.3 Selective Ion Meter, or a pH meter with expandedmillivolt scale equipped with a cyanide act

32、ivity electrode anda reference electrode.7.4 Mixer, magnetic, with a TFE-fluorocarbon-coated stir-ring bar.7.5 Buret, Koch, micro, 2- or 5-mL, calibrated in 0.01 mL.7.6 Ion Chromatograph, high performance ion chromato-graph equipped with a 10-L sample solution injection deviceand pulsed-electrochemi

33、cal detector.7.7 Chromatography Column, Dionex IonPac AS7 anion-exchange, 4 3 250 mm and matching guard column or equiva-lent.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to

34、 the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the deter

35、mination.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water that meetsthe purity specifications of Type I or Type II water, presentedin D 1193.8.3 Acetic Acid (1 + 9)Mix 1 volume of glacial aceticacid with 9 volumes of water.8.4 Acetate Buffer

36、Dissolve 410 g of sodium acetate tri-hydrate (NaC2H3O23H2O) in 500 mL of water. Add glacialacetic acid to yield a solution pH of 4.5, approximately 500mL.8.5 Barbituric Acid.8.6 Calcium Hypochlorite Solution (50 g/L)Dissolve 5 gof calcium hypochlorite (Ca(OCl)2) in 100 mL of water. Storethe solution

37、 in an amber glass bottle in the dark. Prepare freshmonthly.8.7 Chloramine-T Solution (10 g/L)Dissolve 1.0 g of thewhite-colored, water-soluble grade powder chloramine-T in100 mL of water. Prepare fresh weekly.8.8 Cyanide Solution, Stock (1 mL = 250 g CN)Dissolve 0.6258 g of potassium cyanide (KCN)

38、in 40 mL ofsodium hydroxide solution (40 g/L). Dilute to 1 L with water.Mix thoroughly. Standardize with standard silver nitrate solu-tion following the titration procedure (see 16.2). (WarningBecause KCN is highly toxic, avoid contact or inhalation (see9). Commercial solutions may also be used if c

39、ertified by themanufacturer and used within the recommended storage date.8.8.1 Cyanide I Solution, Standard (1 mL = 25 g CN)Dilute a calculated volume (approximately 100 mL) of KCNstock solution to 1 L with NaOH solution (1.6 g/L).8.8.2 Cyanide II Solution, Standard (1 mL = 2.5 g CN)Dilute exactly 1

40、00 mL of KCN standard solution I to 1 L withNaOH solution (1.6 g/L).8.8.3 Cyanide III Solution, Standard (1 mL = 0.25 gCN) Dilute exactly 100 mL of KCN standard solution II to1 L with NaOH solution (1.6 g/L). Prepare fresh solution dailyand protect from light.8.8.4 Cyanide IV Solution, Standard (1 m

41、L = 0.025 gCN) Dilute exactly 100 mL of KCN standard solution III to1 L with NaOH solution (1.6 g/L). Prepare fresh solution dailyand protect from light.8.9 Hydrogen Peroxide Solution, 3 %Dilute 10 mL of30 % hydrogen peroxide (H2O2) to 100 mL. Prepare freshweekly.8.10 Isooctane, Hexane, Chloroform (

42、solvent preference inthe order named).8.11 Lead Carbonate (PbCO3), Lead Acetate (Pb(C2H3O2)23H2O), or Lead Nitrate (Pb(NO3)2)Lead acetate andlead nitrate can be put in solution with water, if desired, at asuggested concentration of 50 g/L.8.12 Lime, hydrate (Ca(OH)2), powder.8.13 Magnesium Chloride

43、SolutionDissolve 510 g ofmagnesium chloride (MgCl26H2O) in water and dilute to 1 L.8.14 Potassium Iodide-Starch Test Paper.8.15 Pyridine-Barbituric Acid Reagent Place 15 g ofbarbituric acid in a 250-mL volumetric flask and add justenough water to wash the sides of the flask and wet thebarbituric aci

44、d.Add 75 mL of pyridine and mix.Add 15 mL ofhydrochloric acid (sp gr 1.19), mix, and cool to room tempera-ture. Dilute to volume with water and mix until all of thebarbituric acid is dissolved. This solution is usable for about 6months if stored in a cold dark place.8.16 Rhodanine Indicator Solution

45、 (0.2 g/L)Dissolve 0.02g of (p-dimethylaminobenzylidene) in 100 mL of acetone.8.17 Silver Nitrate Solution, Standard (0.01 N)Dissolve1.6987 g of silver nitrate (AgNO3) in water and dilute to 1 L.Mix thoroughly. Commerical solutions that are certified at thedesignated normality are suitable if used w

46、ithin the manufac-turers recommended storage date otherwise standardize asdescribed in sections 8.17.1 and 8.17.2. Store in a darkcontainer.8.17.1 Potassium Chloride (KCl) Primary Standardpurity 99.98 % minimum. Ignite KCl for4hat500C inplatinum or high-silica vessels. Borosilicate vessels are unsat

47、-isfactory for this purpose. Store in desiccator prior to use.8.17.2 StandardizationDissolve 1.000 g of primary stan-dard KCl (see 8.17.1), in 150 mL of water containing 1 mL ofHNO3(1 + 1) in a 1-L volumetric flask, dilute to volume andmix. Transfer 15 mL of the 1g/L potassium chloride solution toa

48、tared 250-mL beaker by pipet, record the weight to thenearest 0.01 g, dilute to about 100-mL with deionized waterand autotitrate with 0.0100 M Silver Nitrate Titrant using asilver indicator electrode and record the titrant volume. Calcu-late the molarity of the titrant as follows:A 5 0.01341 B/Cwher

49、e:4Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D2036063A = molarity of titrant, moles/L0.01341 = molarity of 1 g/L potassium chloride primarystandard solution.B = weight of 1 g/L sodium chloride solut