1、Designation: D 3869 04Standard 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 (e) 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,an
3、d 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 iodi
4、de (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 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 practice
7、s 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 1129 Terminology Relating to WaterD 1193 Specification for Reagent WaterD 2777 Practice for Determination of Precision and B
8、ias ofApplicable Methods of Committee D19 on WaterD 3370 Practices for Sampling Water from Closed ConduitsD 5810 Guide for Spiking Into Aqueous SamplesD 5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisE60Practice for Analysis of Metals, Ores, and R
9、elatedMaterials by Molecular Absorption SpectrometryE 200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions for Chemical AnalysisE 275 Practice for Describing and Measuring Performanceof Ultraviolet, Visible, and Near Infrared Spectrophotom-eters3. Terminology3.
10、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 by comparison of the concentrations of theirdissolved constituents. The results are used to evaluate theorigin o
11、f 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 jurisdiction of ASTM Committee D19 onWater and are the direct responsibility of Subcommittee D19.05 on InorganicConstitue
12、nts in Water.Current edition approved March 1, 2004. Published April 2004. Originallyapproved in 1979. Last previous edition approved in 1999 as D 3869 95 (1999).2Additional information is contained in the following references:Collins, A. G., Geochemistry of Oilfield Waters, Elsevier, New York, N. Y
13、., 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, G. E., and Collins, A. G., “Fluoride and Iodide SelectiveElectrodesApplied to Oilfield BrineAnalysis.
14、” 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 Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe AST
15、M 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. Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicate
16、d, 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 may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit i
17、ts use without lessening theaccuracy of the determination.5.2 Purity of Water Unless otherwise indicated, referenceto water shall be understood to mean reagent water conformingto Specification D 1193, Type I. Other reagent water types maybe used provided it is first ascertained that the water is ofs
18、ufficiently 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. Sampling6.1 Collect the sample in accordance with Practices D 3370.TEST METHOD AVOLUMETRIC FOR IODIDEAN
19、D 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 method can be used for concentrations as high as 2000mg/L iodide and 6500 mg/L bromide.8. Summary of T
20、est 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 iodine which is titrated with sodium thiosulfate.8.2 Iodide and bromide are oxidized to iodate and bromate,
21、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 thiosulfate.8.3 The bromide concentration is calculated by differencebetween the iodide and combined iodide a
22、nd 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 fluoride.NOTE 1Brines containing surfactants can cause emulsion problems,in which case a suitable emulsio
23、n 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 6 1C.10.5 Erlenmeyer Flasks, 250-mL.11. Reagents11.1 Acetic Acid, glacial.11.2 Ammonium Molybdate SolutionDissolve2gofam
24、-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 amber bottle.11.4 Calcium Carbonate (CaCO3), powdered.11.5 Calcium Oxide (CaO), anhydrous powdered.11
25、.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)Add 1 volume of HCl(sp gr 1.19) to 199 volumes of water.11.9 Methyl Red Indicator Solution (0.1 g/L)Dis
26、solve0.01 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 American Chemical Society (ACS)specifications.11.12 Sodium Acetate Solution (275 g/L)Dissolve 275 gof
27、 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, iodate,bromide, and bromate.11.14 Sodium Formate Solution (500 g/L)Dissolve 50 gof sodium formate (NaCHO2
28、) 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 % NaClO.11.16 Sodium Thiosulfate Solution (0.1 N)Prepare andstandardize as directed in Practice E 20
29、0.11.17 Sodium Thiosulfate Solution (0.01 N)With a cali-brated pipet transfer 25 mL of the 0.1 N Na2S2O3solution intoa 250-mL volumetric flask. Dilute to the mark with water thathas been freshly boiled and cooled then mix well. This solutionshall be prepared not more than 2 days before it is to be u
30、sed.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 to stand for 2 h. Add 6 mL of glacialacetic acid. Mix again and add sufficient HCl (sp gr 1.19) toadjust th
31、e pH to 4.0. Store in a glass-stoppered bottle. Starchsolution prepared in this manner will remain chemically stablefor at least 1 year.11.18.1 If a proprietary starch indicator powder is used, itshall be so indicated in reporting the results of the analysis.4Reagent Chemicals, American Chemical Soc
32、iety 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. Pharmaceut
33、ical Convention, Inc. (USPC), Rockville,MD.D 3869 04212. Procedure12.1 To remove iron, manganese, and organic matter fromthe sample, add exactly 100 mL of sample to a bottle. Add 1 gof calcium oxide, stopper, and place the mixture in a shaker for1 h. Allow the mixture to stand overnight and filter o
34、n a dryfolded filter, discarding the first 20 mL that come through.Brines with specific gravities less than 1.009 may be filteredwithout standing overnight. Prepare a blank in the samemanner.12.2 Transfer an aliquot of the filtrate containing 1 to 2 mgof iodide to a 250-mLErlenmeyer flask.Add suffic
35、ient water toprovide a total volume of 75 mL.12.3 Add 3 drops of methyl red indicator. Add HCl(1 + 199) dropwise until the mixture is just slightly acid.12.4 Add 10 mL of sodium acetate solution, 1 mL of glacialacetic acid, 4 mL of bromine water, and allow to stand for 5min.12.5 Add 2 mL of sodium f
36、ormate solution, blow out anybromine vapor from the neck of the flask, and wash down thesides with water.12.6 When the solution is completely colorless, add 0.2 g ofKF and 0.5 g of KI. Mix until dissolved and add 15 mL of HCl(1 + 1).12.7 For final treatment and titration of the sample, proceedas dir
37、ected 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 ofbromide to a 250-mL Erlenmeyer flask.Add sufficient water tomake the total volume 75 mL.12.9 If necessary add sufficient NaCl to produce a 3-gchloride content. Add,
38、in order, 10 mL of sodium hypochloritesolution and approximately 0.4 g of CaCO3(or enough so thatapproximately 0.1 g will remain after the next step).12.10 Adjust the pH of the solution with HCl (1 + 3) to a pHbetween 5.5 and 6.0. Heat at 90C for 10 min. (Asmall amountof undissolved CaCO3should rema
39、in at this point.)12.11 Remove the flask and cautiously add 10 mL ofsodium formate solution, return the flask to the water bath, andkeep the contents hot for 5 min more. Observe the timingclosely. Rinse down the inside of the flask with a few millilitresof water and allow the solution to cool to roo
40、m temperature.Do not use a water bath.12.12 Add 3 drops of ammonium molybdate solution, 0.5 gof KF (if iron is present), 0.5 g of KI, mix until dissolved, andacidify with 15 mL of HCl (1 + 1).12.13 Titrate the sample (12.7) for iodide or the sample(12.12) for combined iodide and bromide with 0.01 N
41、sodiumthiosulfate solution using starch indicator. Disregard any returnof 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
42、 of Na2S2O3, sample solution, andD = millilitres of Na2S2O3blank 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 pr
43、ecision (ST) and single-operator preci-sion ( So) of this test method within their designated rangesvary with the quantity being tested in accordance with Table 1and Table 2.14.2 The bias of the test method determined from recoveriesof known amounts of iodide and bromide in a series ofprepared stand
44、ards are given in Table 1 and Table 2.NOTE 2The precision 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
45、determinations on each of2 days. Practice D 2777 was used 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 2777-98, these precision
46、and bias data do meet existingrequirements for interlaboratory studies of Committee D19 testmethods.15. Quality Control15.1 In order to be certain that analytical values obtainedusing these test methods are valid and accurate within theconfidence limits of the test, the following QC procedures mustb
47、e followed when analyzing iodide and bromide.15.2 Calibration and Calibration Verification15.2.1 Verify the sodium thiosulfate solution (11.17) ac-cording to E 200.15.2.2 Verify solution by analyzing a sample at the concen-tration of a mid-range standard should fall within 6 15% of theknown concentr
48、ation.15.2.3 If calibration cannot be verified, remake the sodiumthiosulfate solution.15.3 Initial Demonstration of Laboratory Capability5Supporting data are available from ASTM Headquarters. RequestRR:D191061.D 3869 04315.3.1 If a laboratory has not performed the test before, or ifthere has been a
49、major change in the measurement system, forexample, new analyst, new instrument, and so forth, a precisionand bias study must be performed to demonstrate laboratorycapability.15.3.2 Analyze seven replicates of a known solution pre-pared from an Independent Reference Material containing amid-range concentration of iodide and bromide. The matrixand chemistry of the solution should be equivalent to thesolution used in the collaborative study. Each replicate must betaken through the complete analytical test method includingany sample preservation and pretre
