1、Designation: D 3869 09Standard Test Methods forIodide and Bromide Ions in Brackish Water, Seawater, andBrines1This standard is issued under the fixed designation D 3869; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast 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 methods2cover the determination of solubleiodide and bromide ions, or both, in brackish water, seawater,and
3、 brines. Four test methods are given as follows:1.1.1 Test Method A for both Iodide and Bromide IonsVolumetric, for concentrations from 0.2 to 2000 mg/L iodideand from 5 to 6500 mg/L bromide (Sections 7-15).1.1.2 Test Method B for Iodide IonColorimetric, forconcentrations from 0.2 to 2000 mg/L iodid
4、e (Sections 16-25).1.1.3 Test Method C for Iodide IonSelective electrode, forconcentrations from 1 to 2000 mg/L iodide (Sections 26-34).1.1.4 Test Method D for Bromide IonColorimetric, forconcentrations from 40 to 6500 mg/L bromide (Sections35-44).1.2 Test MethodAis intended for use on all brackish
5、waters,seawaters, and brines that contain appreciable amounts ofiodide or bromide ions or both. Test Methods B, C, and D,because of their rapidity and sensitivity, are recommended forthe analysis of brackish waters, seawaters, and brines in thefield and in the laboratory.1.3 Samples containing from
6、0.2 to 2000 mg/L of iodide or5 to 6500 mg/L of bromide may be analyzed by these methods.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associa
7、ted 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 statements, see 20.2 and 39.2.2. Referenced Documents2.1 ASTM Standards:3D 1
8、129 Terminology Relating to WaterD 1193 Specification for 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 5810 Guide for Spiking into Aqueous SamplesD 5847 Practice for W
9、riting Quality Control Specificationsfor Standard Test Methods for Water AnalysisE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Molecular Absorption SpectrometryE 200 Practice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for ChemicalAnalysisE 2
10、75 Practice for Describing and Measuring Performanceof Ultraviolet and Visible Spectrophotometers3. Terminology3.1 DefinitionsFor definitions of terms used in these testmethods, refer to Terminology D 1129.4. Significance and Use4.1 Identification of a brackish water, seawater, or brine isdetermined
11、 by comparison of the concentrations of theirdissolved constituents. The results are used to evaluate theorigin of the water, determine if it is a possible pollutant ordetermine if it is a commercial source of a valuable constituentsuch as iodine or bromine.1These test methods are under the jurisdic
12、tion of ASTM Committee D19 onWater and are the direct responsibility of Subcommittee D19.05 on InorganicConstituents in Water.Current edition approved May 15, 2009. Published June 2009. Originallyapproved in 1979. Last previous edition approved in 2004 as D 3869 04.2Additional information is contain
13、ed in the following references: Collins,A. G.,Geochemistry of Oilfield Waters, Elsevier, New York, N.Y., 1975, 496 pp.American Petroleum Institute, API Recommended Practice for Analysis ofOilfield Waters, Subcommittee on Analysis of Oilfield Waters, API RP, 45 2nd ed,1968, 49 pp.Hoke, S. H, Fletcher
14、, G. E., and Collins, A. G., “Fluoride and Iodide SelectiveElectrodesApplied to Oilfield BrineAnalysis,” US Department of Energy, Report ofInvestigations, BETC/RI-78/7, 1978.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For
15、Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Rea
16、gents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specification of the Committeeon Analytical Reagents of the American Chemical Society,4where such specifications are available. Other grades
17、may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 Purity of WaterUnless otherwise indicated, referenceto water shall be understood to mean reagent water conformingto Specification D 119
18、3, Type I. Other reagent water types maybe used provided it is first ascertained that the water is ofsufficiently high purity to permit its use without adverselyaffecting the precision and bias of the test method. Type IIIwater was specified at the time of round robin testing of thistest method.6. S
19、ampling6.1 Collect the sample in accordance with Practices D 3370.TEST METHOD AVOLUMETRIC FOR IODIDEAND BROMIDE7. Scope7.1 This test method is applicable to brackish waters,seawaters, and brines, and is recommended for such waterscontaining appreciable amounts of iodide or bromide, or both.The test
20、method can be used for concentrations as high as 2000mg/L iodide and 6500 mg/L bromide.8. Summary of Test Method8.1 Iodide in the sample is oxidized with bromine to iodatein a buffered solution, the excess bromine is decomposed withsodium formate, and the iodate reacts with added iodide toform iodin
21、e which is titrated with sodium thiosulfate.8.2 Iodide and bromide are oxidized to iodate and bromate,respectively, with hypochlorite. The excess hypochlorite isdestroyed with sodium formate, leaving iodate and bromate toreact with added iodide to liberate iodine which is titrated withsodium thiosul
22、fate.8.3 The bromide concentration is calculated by differencebetween the iodide and combined iodide and bromide deter-minations.9. Interferences9.1 Iron, manganese, and organic matter can interfere (Note1).They are removed by precipitation and filtration. Remainingtraces of iron are masked with flu
23、oride.NOTE 1Brines containing surfactants can cause emulsion problems,in which case a suitable emulsion breaker can be used.10. Apparatus10.1 Mechanical Bottle Shaker.10.2 Bottles, 200-mL, for use on mechanical shaker.10.3 Pipets.10.4 Hot-Water Bath, thermostatically controlled to 61C.10.5 Erlenmeye
24、r Flasks, 250-mL.11. Reagents11.1 Acetic Acid, glacial.11.2 Ammonium Molybdate SolutionDissolve2gofam-monium molybdate in water and dilute to 100 mL.11.3 Bromine Water (Saturated)Add to 250 mL of waterslightly more liquid bromine (8 to 10 mL) than will dissolve onshaking. Store in a glass-stoppered
25、amber bottle.11.4 Calcium Carbonate (CaCO3), powdered.11.5 Calcium Oxide (CaO), anhydrous powdered.11.6 Hydrochloric Acid (1 + 1)Add 1 volume of HCl (spgr 1.19) to 1 volume of water.11.7 Hydrochloric Acid (1 + 3)Add 1 volume of HCl (spgr 1.19) to 3 volumes of water.11.8 Hydrochloric Acid (1 + 199)Ad
26、d 1 volume of HCl(sp gr 1.19) to 199 volumes of water.11.9 Methyl Red Indicator Solution (0.1 g/L)Dissolve0.01 g of water-soluble methyl red in water and dilute to 100mL.11.10 Potassium Fluoride (KF2H2O)crystalline.11.11 Potassium Iodide (KI), crystals, free of iodates whentested in accordance with
27、American Chemical Society (ACS)specifications.11.12 Sodium Acetate Solution (275 g/L)Dissolve 275 gof sodium acetate trihydrate (NaC2H3O23H2O) in water, todilute to 1 L, and filter.11.13 Sodium Chloride (NaCl), crystals, which, in additionto satisfyingACS specifications, must be free of iodide, ioda
28、te,bromide, and bromate.11.14 Sodium Formate Solution (500 g/L)Dissolve 50 gof sodium formate (NaCHO2) in hot water and dilute to 100mL. This solution must be freshly prepared.11.15 Sodium Hypochlorite SolutionUse a fresh commer-cial sodium hypochlorite or bleach solution containing ap-proximately 5
29、 % NaClO.11.16 Sodium Thiosulfate Solution (0.1 N)Prepare andstandardize as directed in Practice E 200.11.17 Sodium Thiosulfate Solution (0.01 N)With a cali-brated pipet transfer 25 mL of the 0.1 N Na2S2O3solution(11.16) into a 250-mLvolumetric flask. Dilute to the mark withwater that has been fresh
30、ly boiled and cooled then mix well.This solution shall be prepared not more than 2 days before itis to be used.11.18 Starch Indicator SolutionMake a paste of6gofarrowroot or soluble iodometric starch with cold water. Pourthe paste into 1 L of boiling water. Add 20 g of KOH, mixthoroughly, and allow
31、to stand for 2 h. Add 6 mL of glacialacetic acid. Mix again and add sufficient HCl (sp gr 1.19) toadjust the pH to 4.0. Store in a glass-stoppered bottle. Starchsolution prepared in this manner will remain chemically stablefor at least 1 year.4Reagent Chemicals, American Chemical Society Specificati
32、ons, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention,
33、Inc. (USPC), Rockville,MD.D386909211.18.1 If a proprietary starch indicator powder is used, itshall be so indicated in reporting the results of the analysis.12. Procedure12.1 To remove iron, manganese, and organic matter fromthe sample, add exactly 100 mL of sample to a bottle. Add 1 gof calcium oxi
34、de (11.5), stopper, and place the mixture in ashaker for 1 h. Allow the mixture to stand overnight and filteron a dry folded filter, discarding the first 20 mL that comethrough. Brines with specific gravities less than 1.009 may befiltered without standing overnight. Prepare a blank in the samemanne
35、r.12.2 Transfer an aliquot of the filtrate containing 1 to 2 mgof iodide to a 250-mLErlenmeyer flask.Add sufficient water toprovide a total volume of 75 mL.12.3 Add 3 drops of methyl red indicator (11.9). Add HCl(1 + 199) (11.8) dropwise until the mixture is just slightly acid.12.4 Add 10 mLof sodiu
36、m acetate solution (11.12),1mLofglacial acetic acid (11.1), 4 mL of bromine water (11.3), andallow to stand for 5 min.12.5 Add 2 mL of sodium formate solution (11.14), blowout any bromine vapor from the neck of the flask, and washdown the sides with water.12.6 When the solution is completely colorle
37、ss, add 0.2 g ofKF (11.10)and0.5gofKI(11.11). Mix until dissolved and add15 mL of HCl (1 + 1) (11.6).12.7 For final treatment and titration of the sample, proceedas directed in (12.13).12.8 To determine the combined iodide and bromide, trans-fer an aliquot of the filtrate (12.1) containing 1 to 2 mg
38、 ofbromide to a 250-mL Erlenmeyer flask.Add sufficient water tomake the total volume 75 mL.12.9 If necessary add sufficient NaCl (11.13) to produce a3-g chloride content.Add, in order, 10 mLof sodium hypochlo-rite solution (11.15) and approximately 0.4 g of CaCO3(11.4)(or enough so that approximatel
39、y 0.1 g will remain after thenext step).12.10 Adjust the pH of the solution with HCl (1 + 3) (11.7)to a pH between 5.5 and 6.0. Heat at 90C for 10 min. (Asmallamount of undissolved CaCO3should remain at this point.)12.11 Remove the flask and cautiously add 10 mL ofsodium formate solution (11.14), re
40、turn the flask to the waterbath, and keep the contents hot for 5 min more. Observe thetiming closely. Rinse down the inside of the flask with a fewmillilitres of water and allow the solution to cool to roomtemperature. Do not use a water bath.12.12 Add 3 drops of ammonium molybdate solution (11.2),0
41、.5gofKF(11.10) (if iron is present), 0.5 g of KI (11.11), mixuntil dissolved, and acidify with 15 mL of HCl (1 + 1) (11.6).12.13 Titrate the sample (12.7) for iodide or the sample(12.12) for combined iodide and bromide with 0.01 N sodiumthiosulfate solution (11.17) using starch indicator (11.18).Dis
42、regard any return of blue color after the endpoint.13. Calculation13.1 Calculate the concentration of iodide and bromide ionsin milligrams per litre as follows:13.2 Iodide:C 5 E 2 Dwhere:C = corrected millilitres of Na2S2O3solution,E = millilitres of Na2S2O3, sample solution, andD = millilitres of N
43、a2S2O3blank solution.I2, mg/L 5CNS3 21150where:N = normality of Na2S2O3solution, andS = millilitres of sample.13.3 Bromide:C 5 E 2 DBr2, mg/L 5CNS3 13320 2 Xwhere:X = concentration of Ias determined above.14. Precision and Bias514.1 The overall precision (ST) and single-operator preci-sion (So) of t
44、his test method within their designated ranges varywith the quantity being tested in accordance with Table 1 andTable 2.14.2 The bias of the test method determined from recoveriesof known amounts of iodide and bromide in a series ofprepared standards are given in Table 1 and Table 2.NOTE 2The precis
45、ion and bias estimates are based on the interlabo-ratory study on four artificial brine samples containing various amounts ofiodide, bromide, and interfering ions as shown in Table 3. Two analysts ineach of three laboratories performed duplicate determinations on each of2 days. Practice D 2777 was u
46、sed in developing these precision and biasestimates.14.3 Precision and bias for this test method conforms toPractice D 2777 77, which was in place at the time ofcollaborative testing. Under the allowances made in 1.4 ofD 2777 08, these precision and bias data do meet existingrequirements for interla
47、boratory studies of Committee D19 testmethods.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D191061.TABLE 1 Determination of Precision and Bias of Iodide Ions,Volumetric MethodsAmount Added,mg/LAmountFound, mg/LSOST6BiasStati
48、sticallySignificant (95 %ConfidenceLevel)12.1 11.4 1 1 5.78 yes116.3 112.5 2 3 3.27 yes771 743 12 15 +2.63 no1375 1282 40 73 6.76 yesD386909315. Quality Control15.1 In order to be certain that analytical values obtainedusing these test methods are valid and accurate within theconfidence limits of th
49、e test, the following QC procedures mustbe followed when analyzing iodide and bromide.15.2 Calibration and Calibration Verification15.2.1 Verify the sodium thiosulfate solution (11.17) ac-cording to Practice E 200.15.2.2 Verify solution by analyzing a sample at the concen-tration of a mid-range standard should fall within 615% of theknown concentration.15.2.3 If calibration cannot be verified, remake the sodiumthiosulfate solution.15.3 Initial Demonstration of Laboratory Capability15.3.1 If a laboratory has not performed the test before, or ifther
