1、Designation: D7365 09a (Reapproved 2015)Standard Practice forSampling, Preservation and Mitigating Interferences inWater Samples for Analysis of Cyanide1This standard is issued under the fixed designation D7365; the number immediately following the designation indicates the year oforiginal adoption
2、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 practice is applicable for the collection and pres-ervation of water sam
3、ples for the analysis of cyanide. Thispractice addresses the mitigation of known interferences priorto the analysis of cyanide. Responsibilities of field samplingpersonnel and the laboratory are indicated.1.2 The sampling, preservation and mitigation of interfer-ence procedures described in this pra
4、ctice are recommendedfor the analysis of total cyanide, available cyanide, weak aciddissociable cyanide, and free cyanide by Test Methods D2036,D4282, D4374, D6888, D6994, D7237, D7284, and D7511.The information supplied in this practice can also be applied toother analytical methods for cyanide, fo
5、r example, EPAMethod 335.4.1.3 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
6、 standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2036 Test Methods for Cyanides in WaterD3370 Pra
7、ctices for Sampling Water from Closed ConduitsD3694 Practices for Preparation of Sample Containers andfor Preservation of Organic ConstituentsD3856 Guide for Management Systems in LaboratoriesEngaged in Analysis of WaterD4282 Test Method for Determination of Free Cyanide inWater and Wastewater by Mi
8、crodiffusionD4374 Test Methods for Cyanides in WaterAutomatedMethods for Total Cyanide, Weak Acid DissociableCyanide, and Thiocyanate (Withdrawn 2012)3D4411 Guide for Sampling Fluvial Sediment in MotionD4840 Guide for Sample Chain-of-Custody ProceduresD4841 Practice for Estimation of Holding Time fo
9、r WaterSamples Containing Organic and Inorganic ConstituentsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD6888 Test Method for Available Cyanide with LigandDisplacement and Flow InjectionAnalysis (FIA) UtilizingGas Diffusion Separation and Ampe
10、rometric DetectionD6994 Test Method for Determination of Metal CyanideComplexes in Wastewater, Surface Water, Groundwaterand Drinking Water Using Anion Exchange Chromatog-raphy with UV DetectionD6696 Guide for Understanding Cyanide SpeciesD7237 Test Method for Free Cyanide and Aquatic FreeCyanide wi
11、th Flow Injection Analysis (FIA) Utilizing GasDiffusion Separation and Amperometric DetectionD7284 Test Method for Total Cyanide in Water by MicroDistillation followed by Flow Injection Analysis with GasDiffusion Separation and Amperometric DetectionD7511 Test Method for Total Cyanide by Segmented F
12、lowInjection Analysis, In-Line Ultraviolet Digestion and Am-perometric Detection2.2 U.S. EPA Methods:4EPA Method OIA-1677 Available Cyanide by Flow Injec-tion with Ligand ExchangeEPA Method 335.2 Cyanide, Total (Titrimetric; Spectropho-tometric)EPA Method 335.4 Determination of Total Cyanide bySemi-
13、Automated Colorimetry1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.06 on Methods for Analysis forOrganic Substances in Water.Current edition approved July 15, 2015. Published August 2015. Originallyapproved in 2007. Last p
14、revious edition approved in 2009 as D7365 09a. DOI:10.1520/D7365-09AR15.2For 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 AS
15、TM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from United States Environmental ProtectionAgency (EPA), WilliamJefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460,http:/www.epa.gov.Copyright ASTM International, 100 Barr
16、 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.3 USGS Methods:5USGS I-3300-85USGS I-4302-853. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTerminology D1129 and Guide D6696.3.1.2 refrigeration, nstoring the sample between its
17、 freez-ing point and 6C.3.1.3 holding time, nthe time lapsed from sample collec-tion to sample analysis.4. Summary of Practice4.1 Samples are collected in appropriate containers andmitigated for known interferences either in the field duringsample collection or in the laboratory prior to analysis.5.
18、 Significance and Use5.1 Cyanide is routinely analyzed in water samples, often todemonstrate regulatory compliance; however, improper samplecollection or pretreatment can result in significant positive ornegative bias potentially resulting in unnecessary permit vio-lations or undetected cyanide rele
19、ases into the environment.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in this practice. Unless otherwise indicated, it is intendedthat all reagents shall conform to the specifications of theCommittee on Analytical Reagents of the American ChemicalSociety, wher
20、e such specifications are available.6Other gradesmay be used, provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to
21、mean reagent water that meetsthe purity specifications of Type I or Type II water, presentedin Specification D1193.6.3 Acetate BufferDissolve 410 g of sodium acetate trihy-drate (NaC2H3O23H2O) in 500 mLof water.Add glacial aceticacid to yield a solution pH of 4.5, approximately 500 mL.6.4 Lead Aceta
22、te Test StripsTurns black in presence ofsulfides. Moisten the paper with acetate buffer prior to use.Lead acetate test strips have been shown to be sensitive toabout 50 mg/L S2-.6.5 Potassium Iodide (KI) Starch Test PaperTurns blue inpresence of free chlorine. Commercial alternative test stripsmay b
23、e used if they are shown to be at least as sensitive as theKI starch test strips.6.6 pH Indicator Test StripspH indicator test strips ca-pable of changing color at 0.5 pH units in the range of pH 2 to12. More than one test strip may be necessary to cover thisrange.6.7 Sodium Hydroxide Solution (1 M)
24、In a 1-L volumetricflask, dissolve 40 g NaOH in reagent water and dilute tovolume.6.8 Sodium Hydroxide Solution (50 % wt/vol)In a beaker,dissolve 50 g NaOH in reagent water not to exceed 100 mLtotal volume, then transfer to a 100-mL volumetric flask anddilute to volume. (WarningThis is an exothermic
25、 reactionand the solution will become very hot while being prepared. Itis recommended to place the solution in a water bath to cool.)6.9 Hydrated LimeCa(OH)2powder.6.10 Ethylenediamine Solution (EDA), 3.5%Dilute 3.5mL (or 3.15 g) of anhydrous NH2CH2NH2to 100 mL withwater.6.11 Reducing AgentsAscorbic
26、 acid, sodium arsenite(NaAsO2).6.12 Filter Paper or Syringe equipped with Leur-LockFilters5 m and 0.45 m pore size. If unspecified, use 0.45um pore size.6.13 Dilute Acetic AcidAdd 1 part glacial acetic acid to 9parts water.6.14 Lead Carbonate (PbCO3) or Lead Acetate(Pb(C2H3O2)23H2O, Lead acetate can
27、 be put in solution withwater at a suggested concentration of 50 g/L.6.15 Sulfamic acid (0.4N), H2NSO3HDissolve 40 gH2NSO3H in 1 L of water.6.16 Sample BottlesSee 8.2 for further information aboutsample bottles.7. Hazards7.1 WarningBecause of the toxicity of cyanide, greatcare must be exercised in i
28、ts handling. Acidification of cyanidesolutions produces toxic hydrocyanic acid (HCN). Adequateventilation is necessary when handling cyanide solutions and afume hood should be utilized whenever possible.7.2 WarningMany of the reagents used in these testmethods are highly toxic. These reagents and th
29、eir solutionsmust be disposed of properly.8. Procedure8.1 Laboratory personnel and field samplers should followthe practices described in Guide D3856. When sampling closedconduits such as process streams refer to Practices D3370.When sampling fluvial sediment in motion or open channelflow refer to G
30、uide D4411. It is recommended to consult withthe analytical laboratory prior to collecting samples to ensurethe proper sample volume, containers, etc., as these parametersmay vary depending on the analytical methods used to measurethe cyanide.5Available from United States Geological Survey (USGS), U
31、SGS NationalCenter, John W. Powell Bldg, 12201 Sunrise Valley Dr., Reston, VA 20192,http:/www.usgs.gov.6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see An
32、nual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D7365 09a (2015)28.2 Sample Containers:8.2.1 Sample containers shall be made of materials that willnot contaminate
33、 the sample, cleaned thoroughly to remove allextraneous surface contamination prior to use. Chemicallyresistant glass containers as well as rigid plastic containersmade of high density polyethylene (HDPE) are suitable.Samples should be collected and stored in amber bottles tominimize exposure to ult
34、raviolet radiation in the samplecontainers. If samples will only be tested for total cyanide,amber containers are not mandatory.8.2.2 Virgin commercially-cleaned containers certified to befree of contamination are recommended; otherwise, washcontainers with soap or biodegradable detergent if require
35、d,then dry by draining. For further information on samplecontainers, see Practices D3694.8.3 Sample Collection, Preservation, and Mitigation ofInterferences:8.3.1 Collect a sample volume that is sufficient to theanalytical method into a sample bottle described above. If therequired sample volume is
36、not specified, usually 1 L issufficient for most analytical test methods, however, flowinjection and automated methods usually consume consider-ably less sample volume than manual methods.8.3.2 Unless otherwise specified, samples must be analyzedwithin 14 days. Certain sample matrices may require a
37、shorterholding time or immediate analysis to avoid cyanide degrada-tion due to interferences. Hold the sample no longer than thetime necessary to preclude a change in cyanide concentration.A holding time study described in Practice D4841 is requiredif there is evidence that a change in cyanide occur
38、s frominterferences which would cause the holding time to be shorterthan specified in this section, or within the time the samplewould be held if shorter than the time specified in this section.Potential interferences and their corresponding analyticalmethods are shown in Table 1.NOTE 1It is recomme
39、nded to investigate holding times for samplesthat meet any of the following conditionsdisinfected by chloraminationor ultraviolet irradiation, ammonia present and chlorinated, sulfur dioxideor sulfite used to dechlorinate, or if aldehydes are known or suspected tobe present.8.3.3 In the absence of i
40、nterference, simple cyanides such asHCN, KCN, and NaCN are determined readily by each of thedeterminative steps, however, to determine “total” cyanide,metal cyanide bonds must be broken and cyanide separated toproduce simple cyanide. In most total cyanide methods, this isaccomplished by distillation
41、 from acid solution. Althoughdistillation is assumed to eliminate or at least minimize mostinterferences, the high temperature and strong acid solutionscan potentially introduce significant positive or negative bias.Interferences for total cyanide by distillation are listed inTables 2 and 3. Interfe
42、rences are also dependent on thedeterminative step, which are shown in Table 4.8.3.4 There may be interferences that are not mitigated bythis procedure. Any technique for removal or suppression ofinterference may be employed, provided the laboratory dem-onstrates that it more accurately measures cya
43、nide throughquality control measures described in the analytical testmethod. Any removal or suppression technique not describedin this practice or the analytical test method should bedocumented along with supporting data. A challenge solutionwith potential interferences for cyanide analysis is descr
44、ibed inX1.1.1, which can be used as a sample matrix to examineanalytical method performance.8.3.5 Treat the sample immediately upon sample collectionusing any or all of the following techniques as necessary,followed by adjustment of the sample to pH 10 andrefrigeration. If applicable, laboratory mit
45、igation techniquesare also specified. Preserve the sample immediately (within 15minutes of collection or treatment using procedures describedin this practice) by adding 1 mL of 1M NaOH (6.7) per litre ofsample, and then verify that the pH is greater than pH 10 withindicator test strips (6.6). If nec
46、essary, continue to add sodiumhydroxide (6.7 or 6.8) drop wise until the pH is greater than pH10 being careful not to add excess. Do not add NaOH if thecyanide concentration would change as a result of the addition.8.3.5.1 Adding NaOH to samples containing formaldehyde(see Note 2 in 8.3.8) can possi
47、bly increase the cyanideconcentration during storage. Conversely, adding NaOH tosamples containing sulfite (see Note 3 in 8.4.2.2) can rapidlydecrease the cyanide concentration. If the addition or lack ofaddition of NaOH would affect the holding time, hold thesample for a time no longer than the tim
48、e necessary to maintainsample integrity (8.3.2).8.3.6 SulfideDuring sample collection, test for the pres-ence of sulfide by placing a drop of sample on a lead acetatetest strip that has been previously moistened with acetatebuffer. If the test strip turns black, sulfide is present (aboveapproximatel
49、y 50 mg/L S2-) and treatment is necessary asdescribed below.8.3.6.1 If the sample contains sulfide as indicated with alead acetate test strip or is known to contain sulfides that willinterfere with the test method, dilute the sample with reagentwater until the lead acetate test strip no longer indicates thepresence of sulfide (1 % suspended solids) or if the sample is known orsuspected to contain particulate cyanides (for example, ferricferro cyanide or Prussian blue), save the solids for extraction asdescribed in 8.4.3 on particulate cyanides, otherwi
