ASTM D6581-2018 red 1875 Standard Test Methods for Bromate Bromide Chlorate and Chlorite in Drinking Water by Suppressed Ion Chromatography.pdf

1、Designation: D6581 12D6581 18Standard 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.1. Scope Scope*1.1 These multi-test methods cover the determination of the oxyhalideschlorite, br

3、omate, and chlorate, and bromide, in rawwater, finished drinking water and bottled (non-carbonated) water by chemically and electrolytically suppressed ion chromatog-raphy. The ranges tested using these test methods for each analyte were as follows:Range SectionsTest Method A:Chemically SuppressedIo

4、n Chromatography8 to 20Chlorite 5 to 500 g/LBromate 1 to 25 g/LBromide 5 to 250 g/LChlorate 5 to 500 g/LTest 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 extended by ap

5、propriate 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 these test methods.However, analysis of these ions is not the object of these test methods.1.2 It is the use

6、rs responsibility to ensure the validity of these test methods for waters of untested matrices.1.3 These test methods are technically equivalent with Part B of U.S. EPA Method 300.1,2 titled “The Determination ofInorganic Anions in Drinking Water by Ion Chromatography.”1.4 The values stated in eithe

7、r SI or inch-pound units are to be regarded as the standard. The values given in parentheses arefor information only.mathematical conversions to inch-pound units that are provided for information only and are not consideredstandard.1.5 This standard does not purport to address all of the safety conc

8、erns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.6 This international standard was developed in accorda

9、nce with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.1 These test methods are under the j

10、urisdiction of ASTM Committee D19 on Water and are the direct responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved March 1, 2012May 1, 2018. Published April 2012May 2018. Originally approved in 2000. Last previous edition approved in 20082012 asD6581 08.D6

11、581 12. DOI: 10.1520/D6581-12.10.1520/D6581-18.2 U.S. EPA 300.1, Cincinnati, 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

12、adequately depict all changes accurately, ASTM recommends that users 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.*A Summary of Changes section appears at the end of this standardCopyright A

13、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:3D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods

14、of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3856 Guide for Management Systems in Laboratories Engaged in Analysis of WaterD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Ana

15、lysis3. Terminology3.1 DefinitionsDefinitions: For definitions of terms used in the test methods, refer to Terminology D1129.3.1.1 For definitions of terms used in this standard, refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 analytical columncolumn, nthe ion exc

16、hange column used to separate the ions of interest according to their retentioncharacteristics prior to detection.3.2.2 analytical column setset, na combination of one or more guard columns, followed by one or more analytical columnsused to separate the ions of interest. All of the columns in series

17、 then contribute to the overall capacity and resolution of theanalytical column set.3.2.3 eluenteluent, nthe ionic mobile phase used to transport the sample through the chromatographic system.3.2.4 guard columncolumn, na column used before the analytical column to protect it from contaminants, such

18、asparticulates or irreversibly retained material.3.2.5 ion chromatographychromatography, na form of liquid chromatography in which ionic constituents are separated byion exchange then detected by an appropriate detection means, typically conductance.3.2.6 resolutionresolution, nthe ability of an ana

19、lytical column to separate the method analytes under specific testconditions.3.2.7 suppressor devicedevice, nan ion exchange based device that is placed between the analytical column set and theconductivity detector. Its purpose is to minimize detector response to the ionic constituents in the eluen

20、t, in order to lowerbackground conductance; and at the same time enhance the conductivity detector response of the ions of interest.3.2.7.1 chemical suppressionsuppression, nthe use of an acid solution to the suppressor in order to suppress the backgroundconductivity.3.2.7.2 electrolytic suppressor

21、devicedevice, nelectrolytic suppression is an ion exchange device that is placed between theanalytical column and the conductivity detector. Its purpose is similar to a suppressor device, however, it does not require additionof acid. Instead the electrolytic suppressor generates protons electrolytic

22、ally and plugs into an electrical power source on typicallylocated on 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 chlorat

23、e is associated 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 precurs

24、or to the 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, w

25、heresuch 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.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM C

26、ustomer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.4 “ReagentReagent Chemicals, American Chemical Society Specifications,”Specifications, Am.American Chemical Soc.,Society, Washington, DC. For sugg

27、estions on thetesting of reagents not listed by the American Chemical Society, see “AnalarAnalar Standards for Laboratory Chemicals,”Chemicals, by BDH Ltd., Poole, Dorset, U.K.,and the “United States Pharmacopoeia.”United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc

28、. (USPC), Rockville, MD.D6581 1825.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean 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

29、 to permit its use without adversely affecting the bias and precision of the determination.6. Precautions6.1 These test methods address the determination of very low concentrations of selected anions. Accordingly, every precautionshould be taken to ensure the cleanliness of sample containers as well

30、 as other materials and apparatus that come in contact withthe sample.7. Sampling and Sample Preservation7.1 Collect the sample in accordance with PracticePractices D3370, as applicable.7.2 Immediately upon taking the sample, sparge it with an inert gas (for example, nitrogen, argon, or helium) for

31、5 minutes toremove active gases such as chlorine dioxide or ozone. Add 1.00 mL of EDA Preservation Solution (see 15.3) per 1.000 litre ofsample to prevent conversion of residual hypochlorite or hypobromite to chlorate or bromate. This also prevents metal catalyzedconversion of chlorite to chlorate.

32、The oxyhalides in samples preserved in this manner are stable for at least 14 days when storedin amber bottles at 4C.5Test MethodTEST METHOD AChemically Suppressed Ion ChromatographyCHEMICALLY SUPPRESSED ICON CHROMATOGRAPHY8. Scope8.1 This test method covers the determination of the oxyhalideschlori

33、te, 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 follows:Chlorite 5 to 500 g/LBromate 1 to 25 g/LBromide 5 to 250 g/LChlorate 5

34、 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 ionsof interest, such as fluoride, chloride, nitrite, nitrate, phosphate, and sulfate may also be determined using this test method.However, analysis of these ions is n

35、ot the object of this test method.8.2 It is the users responsibility to ensure the validity of this test method for waters of untested matrices.8.3 This test method is technically equivalent with Part B of U.S. EPA Method 300.1,2 titled “The Determination of InorganicAnions in Drinking Water by Ion

36、Chromatography.”8.4 This standard does not purport to address all of the safety concerns, if any, 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

37、. Summary of Test Method A9.1 Oxyhalides (chlorite, bromate, and chlorate) and bromide in raw water, 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

38、 the analytical column set. Here, anions are separated from the sample matrix according totheir retention 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. Th

39、is converts the eluent to carbonic acid, thus reducing the background conductivity. This process 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 ap

40、propriate computer-based data system is typically used for datapresentation.9.2 The anions are identified 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. Interfe

41、rences10.1 Positive errors can be caused by progressive oxidation of residual hypochlorite or hypobromite, or both, in the sample tothe corresponding chlorate and bromate. Furthermore, chlorite can also be oxidized to chlorate, causing negative errors for chlorite5 Hautman, D. P., and Bolyard, M., J

42、ournal of Chromatography, Vol 602, 1992, p. 65.D6581 183and positive errors for chlorate. These interferences are eliminated by the sample preservation steps outlined in 15.3. Chloridepresent at 200 mg/L can interfere with bromate determination.11. Apparatus11.1 Ion Chromatography ApparatusAnalytica

43、l system complete 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 0.10 to 5.0 mL/min of eluent at a pressure of up to 4000 psi (27600 kPa).27 600kPa (4000 p

44、si).11.1.2 Injection ValveA 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. A loop size of up to 50 L may be used without compromisingthe resolution of early eluting peaks, such as chlorit

45、e and bromate.11.1.3 Guard 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

46、 of separating the ions of 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. 1. Conditionsof the eluent may vary by column manufacturer.NOTE 1The Analytical Column Set (see 3.2.2) should be ab

47、le to give baseline resolution of all anions, even for a 50 L 50-L injection containingup to 200 mg/L, each, of common anions, such as chloride, bicarbonate, and sulfate.11.1.5 Suppressor DeviceA suppressor device based upon cation exchange principles. In this test method, simultaneouslyregenerating

48、 suppressor device with sequential carbonate remover was used. An equivalent suppressor device may be usedprovided that comparable method detection limits are achieved and that adequate baseline stability is attained.11.1.6 Conductivity DetectorA low-volume, flow through, temperature stabilized cond

49、uctivity cell equipped with a metercapable of reading from 0 to 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 Table 1.13. Example of ChromatogramIC Conditions213.1 Acarbonate removal device is developed to remove the majority of the carbonate from the eluent and allow hydrox