1、Designation: D6581 08D6581 12Standard Test Methods forBromate, Bromide, Chlorate, and Chlorite in Drinking Waterby Suppressed Ion Chromatography1This standard is issued under the fixed designation D6581; the number immediately following the designation indicates the year oforiginal adoption or, in t
2、he 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This
3、These multi-test method coversmethods cover the determination of the oxyhalideschlorite, bromate, and chlorate, andbromide, in raw water, finished drinking water and bottled (non-carbonated) water by chemically and electrolytically suppressedion chromatography. The ranges tested using this method th
4、ese test methods for each analyte were as follows:Range SectionsTest Method A:Chemically SuppressedIon Chromatography8 to 18Test Method A:Chemically SuppressedIon Chromatography8 to 20Chlorite 20 to 500 g/LChlorite 5 to 500 g/LBromate 5 to 30 g/LBromate 1 to 25 g/LBromide 20 to 200 g/LBromide 5 to 2
5、50 g/LChlorate 20 to 500 g/LChlorate 5 to 500 g/LTest Method B:ElectrolyticallySuppressed IonChromatography19 to 29Test Method B:ElectrolyticallySuppressed IonChromatography21 to 31Chlorite 20 to 1000 g/LBromate 1 to 30 g/LBromide 20 to 200 g/LChlorate 20 to 1000 g/L1.1.1 The upper limits may be ext
6、ended by appropriate sample dilution or by the use of a smaller injection volume. Other ionsof interest, such as fluoride, chloride, nitrite, nitrate, phosphate, and sulfate may also be determined using this method. these testmethods. However, analysis of these ions is not the object of thisthese te
7、st method.methods.1.2 It is the usersusers responsibility to ensure the validity of these test methods for waters of untested matrices.1.3 ThisThese test method ismethods are technically equivalent with Part B of U.S. EPA Method 300.1300.1,2, titled “TheDetermination of Inorganic Anions in Drinking
8、Water by Ion Chromatography”. Chromatography.”1.4 The values stated in either SI or inch-pound units are to be regarded as the standard. The values given in parentheses arefor information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use.
9、It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1 These test methods are under the jurisdiction of ASTM Committee D19 on Water and are the direct responsibility of Subcommi
10、ttee D19.05 on Inorganic Constituentsin Water.Current edition approved Aug. 15, 2008March 1, 2012. Published September 2008April 2012. Originally approved in 2000. Last previous edition approved in 20052008as D6581 00 (2005).D6581 08. DOI: 10.1520/D6581-08.10.1520/D6581-12.2 U.S. EPA Method 300.1, C
11、incinnati, OH, 1997.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that use
12、rs consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 A
13、STM Standards:3D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3856 Guide for Management Systems in Laboratories
14、Engaged in Analysis of WaterD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis3. Terminology3.1 DefinitionsFor definitiondefinitions of terms used in the test methods, refer to Terminology D1129.3.2 Defin
15、itions of Terms Specific to This Standard:3.2.1 analytical columnthe ion exchange column used to separate the ions of interest according to their retentioncharacteristics prior to detection.3.2.2 analytical column seta combination of one or more guard columns, followed by one or more analytical colu
16、mns usedto separate the ions of interest. All of the columns in series then contribute to the overall capacity and resolution of the analyticalcolumn set.3.2.3 eluentthe ionic mobile phase used to transport the sample through the chromatographic system.3.2.4 guard columna column used before the anal
17、ytical column to protect it from contaminants, such as particulates orirreversibly retained material.3.2.5 ion chromatographya form of liquid chromatography in which ionic constituents are separated by ion exchange thendetected by an appropriate detection means, typically conductance.3.2.6 resolutio
18、nthe ability of an analytical column to separate the method analytes under specific test conditions.3.2.7 suppressor devicean ion exchange based device that is placed between the analytical column set and the conductivitydetector. Its purpose is to minimize detector response to the ionic constituent
19、s in the eluent, in order to lower backgroundconductance; and at the same time enhance the conductivity detector response of the ions of interest.3.2.7.1 chemical suppressionthe use of an acid solution to the suppressor in order to suppress the background conductivity.3.2.7.2 electrolytic suppressor
20、 deviceelectrolytic suppression is an ion exchange device that is placed between the analyticalcolumn and the conductivity detector. Its purpose is similar to a suppressor device, however, it does not require addition of acid.Instead the electrolytic suppressor generates protons electrolytically and
21、 plugs into an electrical power source on typically locatedon the chromatography device.4. Significance and Use4.1 The oxyhalides chlorite, chlorate, and bromate are inorganic disinfection by-products (DBPs) of considerable health riskconcern worldwide. The occurrence of chlorite and chlorate is ass
22、ociated with the use of chlorine dioxide, as well as hypochloritesolutions used for drinking water disinfection. The occurrence of bromate is associated with the use of ozone for disinfection,wherein naturally occurring bromide is oxidized to bromate. Bromide is a naturally occurring precursor to th
23、e formation ofbromate.5. Reagents and Materials5.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, wheresuch
24、 specifications are available.4 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without reducing the accuracy of the determination.5.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mea
25、n reagent water conforming toSpecification D1193, Type I. Other reagent water types may be used, provided it is first ascertained that the water is of sufficientlyhigh purity to permit its use without adversely affecting the bias and precision of the determination.3 For referencedASTM standards, vis
26、it theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.4 “Reagent Chemicals, American Chemical Society Specifications,” Am. Chemical Soc., Washington,
27、DC. For suggestions on the testing of reagents not listed by theAmerican Chemical Society, see “Analar Standards for Laboratory Chemicals,” by BDH Ltd., Poole, Dorset, U.K., and the “United States Pharmacopoeia.”D6581 1226. Precautions6.1 These test methods address the determination of very low conc
28、entrations of selected anions. Accordingly, every precautionshould be taken to ensure the cleanliness of sample containers as well as other materials and apparatus that come in contact withthe sample.7. Sampling and Sample Preservation7.1 Collect the sample in accordance with Practice D3370, as appl
29、icable.7.2 Immediately upon taking the sample, sparge it with an inert gas (e.g., (for example, nitrogen, argon, or helium) for 5 minutesto remove active gases such as chlorine dioxide or ozone. Add 1.00 mL of EDA Preservation Solution (see 13.315.3) per 1.000litre of sample to prevent conversion of
30、 residual hypochlorite or hypobromite to chlorate or bromate. This also prevents metalcatalyzed conversion of chlorite to chlorate.The oxyhalides in samples preserved in this manner are stable for at least 14 days whenstored in amber bottles at 4C.5Test Method AChemically Suppressed Ion Chromatograp
31、hy8. Scope8.1 This test method covers the determination of the oxyhalideschlorite, bromate, and chlorate, and bromide, in raw water,finished drinking water and bottled (non-carbonated) water by chemically suppressed ion chromatography. The ranges tested usingthis test method for each analyte were as
32、 follows:Chlorite 20 to 500 g/LBromate 5 to 30 g/LBromide 20 to 200 g/LChlorate 20 to 500 g/LChlorite 5 to 500 g/LBromate 1 to 25 g/LBromide 5 to 250 g/LChlorate 5 to 500 g/L8.1.1 The upper limits may be extended by appropriate sample dilution or by the use of a smaller injection volume. Other ionso
33、f interest, such as fluoride, chloride, nitrite, nitrate, phosphate, and sulfate may also be determined using this test method.However, analysis of these ions is not the object of this test method.8.2 It is the usersusers responsibility to ensure the validity of thesethis test methodsmethod for wate
34、rs of untested matrices.8.3 This test method is technically equivalent with Part B of U.S. EPA Method 300.1300.1,2, titled “The Determination ofInorganic Anions in Drinking Water by Ion Chromatography”. Chromatography.”8.4 This standard does not purport to address all of the safety concerns, if any,
35、 associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.9. Summary of Test Method A9.1 Oxyhalides (chlorite, bromate, and chlorate) and bromide in raw wat
36、er, finished drinking water and bottled water aredetermined by ion chromatography. A sample (200 L) is injected into an ion chromatograph and the pumped eluent (sodiumcarbonate) sweeps the sample through the analytical column set. Here, anions are separated from the sample matrix according totheir r
37、etention characteristics, relative to the anions in the eluent.9.1.1 The separated anions in the eluent stream then pass through a suppressor device, where all cations are exchanged forhydronium ions. This converts the eluent to carbonic acid, thus reducing the background conductivity. This process
38、also convertsthe sample anions to their acid form, thus enhancing their conductivity. The eluent stream then passes through a conductivity cell,where they are detected. A chromatographic integrator or appropriate computer-based data system is typically used for datapresentation.9.2 The anions are id
39、entified based on their retention times compared to known standards. Quantification is accomplished bymeasuring anion peak areas and comparing them to the areas generated from known standards.10. Interferences10.1 Positive errors can be caused by progressive oxidation of residual hypochlorite and/or
40、 hypobromite or hypobromite, orboth, in the sample to the corresponding chlorate and bromate. Furthermore, chlorite can also be oxidized to chlorate, causing5 Hautman, D. P., and Bolyard, M., J. Chromatography, 602, 1992, 65.Hautman, D. P., and Bolyard, M., Journal of Chromatography, Vol 602, 1992,
41、p. 65.D6581 123negative errors for chlorite and positive errors for chlorate. These interferences are eliminated by the sample preservation stepsoutlined in 13.315.3. Chloride present at 200 mg/L and carbonate present at 300 mg/L 200 mg/L can interfere with bromatedetermination. These interferences
42、can be minimized, or eliminated, by the sample pretreatment steps outlined in 13.4. Fluorideand low molecular weight monocarboxylic acids, present at mg/L concentrations, may interfere with the quantitation of chloriteand bromate.11. Apparatus11.1 Ion Chromatography ApparatusAnalytical system comple
43、te with all required accessories, including eluent pump,injector, syringes, columns, suppressor, conductivity detector, data system, and compressed gasses.11.1.1 Eluent PumpCapable of delivering 0.250.10 to 55.0 mL/min of eluent at a pressure of up to 4000 psi.psi (27600 kPa).11.1.2 Injection ValveA
44、 low dead-volume switching valve that will allow the loading of a sample into a sample loop andsubsequent injection of the loop contents into the eluent stream.Aloop size of up to 20050 L may be used without compromisingthe resolution of early eluting peaks, such as chlorite and bromate.11.1.3 Guard
45、 ColumnAnion exchange column typically packed with the same material used in the analytical column. Thepurpose of this column is to protect the analytical column from particulate matter and irreversibly retained material.11.1.4 Analytical ColumnAnion exchange column capable of separating the ions of
46、 interest from each other, as well as fromother ions which commonly occur in the sample matrix. The separation shall be at least as good as that shown in Fig. 1Fig. 2. Theuse of 2 mm ID AS9-HC column, in conjunction with a 50 L sample loop, may improve the peak shape for early eluting anions,such as
47、 chlorite and bromate.Conditions of the eluent may vary by column manufacturer.NOTE 1The Analytical Column Set (see 3.2.2) should be able to give baseline resolution of all anions, even for a 20050 L injection containing upto 200 mg/L, each, of common anions, such as chloride, bicarbonate, and sulfa
48、te.11.1.5 Suppressor DeviceAsuppressor device based upon cation exchange principles. In this method, a membrane-based selftest method, simultaneously regenerating suppressor device with sequential carbonate remover was used.An equivalent suppressordevice may be used provided that comparable method d
49、etection limits are achieved and that adequate baseline stability is attained.11.1.6 Conductivity DetectorA low-volume, flow through, temperature stabilized conductivity cell equipped with a metercapable of reading from 0 to 1000 15 000 S/cm on a linear scale.11.1.7 Data SystemA chromatographic integrator or computer-based data system capable of graphically presenting thedetector output signal versus time, as well as presenting the integrated peak areas.12. Example of ChromatogramIC Conditions112.1 See Fig. 1, Fig. 2, and
