1、Designation:D432703 Designation: D4327 11Standard Test Method forAnions in Water by Chemically Suppressed IonChromatography1This standard is issued under the fixed designation D4327; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、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*1.1 This test method2covers the sequential determination of fluoride, chloride, nitrite, ortho-phosphate, bro
3、mide, nitrate, andsulfate ions in water by chemically suppressed ion chromatography.NOTE 1Order of elution is dependent upon the column used; see Fig. 1.1.2 This test method is applicable to drinking and wastewaters. The ranges tested for this test method for each anion were asfollows (measured in m
4、g/L):Fluoride 0.26 to 8.49Chloride 0.78 to 26.0Nitrite-N 0.36 to 12.0Bromide 0.63 to 21.0Nitrate-N 0.42 to 14.0o-Phosphate 0.69 to 23.1Sulfate 2.85 to 95.01.3 It is the users responsibility to ensure the validity of this test method for other matrices.1.4 Concentrations as low as 0.01 mg/L were dete
5、rmined depending upon the anions to be quantitated,quantified, in singlelaboratory work. Utilizing a 50-L sample volume loop and a sensitivity of 3 S/cm full scale, the approximate detection limitsshown in Table 1 can be achieved. If lower detection levels are required, the sensitivity may be improv
6、ed by using a lower scalesetting (100 L). The analyst must assure optimum instrument performance tomaintain a stable baseline at more sensitive conductivity full-scale settings. can be achieved. Lower detection limits have beenobserved with newer instrumentation, column technology and eluents. The a
7、nalyst must assure optimum instrument performanceto maintain a stable baseline at more sensitive conductivity full-scale settings.1.5 The upper limit of this test method is dependent upon total anion concentration and may be determined experimentally asdescribed in Annex A1. These limits may be exte
8、nded by appropriate dilution or by use of a smaller injection volume.1.6Using alternate separator column and eluents may permit additional anions such as formate or citrate to be determined. Thisis not the subject of this test method.1.71.6 Using alternate separator column and eluents may permit add
9、itional anions such as acetate, formate or citrate to bedetermined. This is not the subject of this test method.1.7 This method update approves the use of Electrolytically generated eluent, electrolytically regenerated eluent, electrolyticsuppression (not autozeroing) and electrolytic trap columns a
10、lso known as Reagent Free Ion Chromatography. This approval isbased on acceptance by the US EPA as referenced in Appendix X21.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.9 This standard does not purport to address all
11、of the safety problems, if any, associated with its use. It is the responsibility1This test method is under the jurisdiction ofASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents in Water.Current edition approved Jan. 10, 2003.15, 2011. Publi
12、shed January 2003.March 2011. Originally approved in 1984. Last previous edition approved in 19972003 asD432797.D4327 03. DOI: 10.1520/D4327-03.10.1520/D4327-11.2The following references may be consulted for additional information:Small, H., Stevens, T. S., and Bauman, W. C., “Novel Ion Exchange Chr
13、omatographic Method Using Conductrimetric Detection,” Analytical Chemistry, Vol 47, 1975,p. 1801.Stevens, T. S., Turkelson, V. T., and Alve, W. R., “Determination of Anions in Boiler Blow Down Water with Ion Chromatography,” Analytical Chemistry, Vol 49, 1977,p. 1176.Sawicki, E., Mulik, J. D., and W
14、itgenstein, E., Editors, Ion Chromatographic Analysis of Environmental Pollutants, Ann Arbor Science Publishers, Ann Arbor, MI, 1978.Mulik, J. D., and Sawicki, E., Editors, Ion Chromatographic Analysis of Environmental Pollutants, Vol/No. 2, Ann Arbor Science Publishers, Ann Arbor, MI, 1979.Weiss, J
15、., Handbook of Ion Chromatography, Dionex Corp., Sunnyvale, CA, 1986.Waters Innovative Methods for Anion Analysis, Waters Chromatography Division of Millipore, Method A 107 and A 116, 1990.Haddad, P. R., and Jackson, P. E., Ion Chromatography: Principles and Applications, Elsevier Scientific Publish
16、ing Co., 1990.1This 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 users co
17、nsult 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 standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohock
18、en, PA 19428-2959, United States.of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D1066 Practice for Sampling SteamD1129 Terminology Relating to WaterD119
19、3 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 ConduitsD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specifications for
20、 Standard Test Methods for Water Analysis3. Terminology3.1 DefinitionsFor definitions of terms used in this test method, refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 analytical columns, na combination of one or more guard columns followed by one or more separat
21、or columns usedto separate the ions of interest.3.2.1.1 DiscussionIt should be remembered that all of the columns in series contribute to the overall capacity of the analyticalcolumn set.3.2.2 chemical suppressor device, na device that is placed between the analytical columns and the detector. Its3.
22、2.2.1 DiscussionThe purpose of the suppressor is to inhibitminimize detector response to the of ionic constituents in theeluent, so as to lower which lowers the detector background and at the same time enhances detector response to the ions of interest.3.2.3 eluenteluent, nthe ionic mobile phase use
23、d to transport the sample through the system.3.2.4 guard column, na column used before the separator column to protect itthe analytical column from contaminants, suchas particulate matter or irreversibly retained materials.3For referencedASTM standards, visit theASTM website, www.astm.org, or contac
24、tASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.FIG. 1 Chromatogram Showing Separation Using the AS4AColumnTABLE 1 Approximate Single Laboratory Detection Limits inReagent WaterA,BAnalyte
25、 Peak No.RetentionTime, minMDLmg/LFluoride 1 1.2 0.01Chloride 2 1.7 0.02Nitrite-N 3 2.0 0.004Bromide 4 2.9 0.01Nitrate-N 5 3.2 0.002o-Phosphate 6 5.4 0.003Sulfate 7 6.9 0.02AData provided by US EPA/EMSL Laboratory, Cincinnati, OH.BColumn: as specified in 7.1.4.Detector: as specified in 7.1.6.Eluent:
26、 as specified in 8.3.Pump rate: 2.0 mL/min.Sample loop: 50 L.D4327 1123.2.5 ion chromatography, na form of liquid chromatography in which ionic constituents are separated by ion exchangefollowed by a suitable detection means. detection.3.2.6 resolutionresolution, nthe ability of an analytical column
27、 to separate constituents under specific test conditions.3.2.7 separator column, nthe ion-exchange or analytical column used to separate the ions of interest according to theirthe ionretention characteristics prior to their detection.4. Summary of Test Method4.1 An aliquot of sample is injected into
28、 an ion chromatograph. The sample is pumped through two columns and columns, asuppressor device, and into a conductivity detector. The analytical column and the guard column are packed with low-capacityanion exchange resin. Ions are separated based on their affinity for the exchange sites of the res
29、in. The suppressor device containsa fiber- or membrane-based cation exchanger that is continuously regenerated by either a flow of dilute sulfuric acid or anelectrolytic suppressor which does not require sulfuric acid. The suppressor device reduces the background conductivity of theeluent to a low o
30、r negligible level by replacing the cations with the hydrogen ion, thereby converting the anions in the sample totheir corresponding acids. The separated anions in their acid form are measured using an electrical-conductivity cell. Anions areidentified based on their retention times compared to know
31、n standards. Quantitation is accomplished by measuring the peak heightor area and comparing it to a calibration curve generated from known standards.5. Significance and Use5.1 Ion chromatography provides for both qualitative and quantitative determination of seven common anions, F,Cl,NO2,HPO42,Br,NO
32、3, and SO42, in the milligram per litre range from a single analytical operation requiring only a few millilitresof sample and taking approximately 10 to 15 min for completion. , in the milligram per liter range from a single analyticaloperation requiring only a few milliliters of sample and taking
33、approximately 10 to 15 min for completion.Additional anions, suchas carboxylic acids, can also be quantified.NOTE 2This test method may be used to determine fluoride if its peak is in the water dip by adding one mL of eluent (at 1003 the concentrationin 8.3) to all 100-mL volumes of samples and stan
34、dards to negate the effect of the water dip. (See 6.3, and also see 6.4.) The quantitation of unretainedpeaks should be avoided.Anions such as low molecular weight organic acids (formate, acetate, propionate, etc.) that are conductive coelute with fluorideand would bias fluoride quantitation in some
35、 drinking waters and most wastewaters. .) The quantitation of unretained peaks should be avoided. Anionssuch as low molecular weight organic acids (formate, acetate, propionate, etc.) that are conductive coelute with fluoride and would bias fluoridequantitation in some drinking waters and most waste
36、waters. The water dip can be further minimized if measures are taken to remove carbonic acid whichremain in the eluent after suppression using carbonate based eluents. There is no water dip if hydroxide eluents are used.5.2 Anion combinations such as Cl/Brand NO2/NO3, which may be difficult to disti
37、nguish by other analytical methods,are readily separated by ion chromatography.6. Interferences6.1 Since chloride and nitrite elute very close together, they are potential interferents for each other. It is advisable not to haveone of these anions present in a ten-fold excess over the other; that is
38、, Cl/NO2ratios higher than 1:10 or 10:1 if both ions areto be quantitated. ratios higher than 1:10 or 10:1 if both ions are to be quantitated or refer to newer column technology.6.2 As with other types of chromatography, if one of the sample components is present at very high levels, it may interfer
39、e bycausing a very large peak on the chromatogram that could mask other peaks present. This type of interference is normallyminimized by dilution of the sample (see Annex A1) and in some instances may be corrected if the concentration of that anionis of interest. However, care should be taken not to
40、 dilute the analyte concentration below its detectable limit.6.3 Water from the sample injection will cause a negative peak or dip in the chromatogram when it elutes, because itsconductivity is less than that of the suppressed eluent. This dip usually occurs before Cl. Any peak of interest eluting n
41、ear thewater dip must be sufficiently resolved from the dip to be accurately quantitated.quantified. Some suggested techniques forelimination of the water dip are described in Appendix X1.6.4 Due to the effect of theThere may be a water dip and the interference of organic acids and due to the presen
42、ce of carbonateions in the separator column, the user of this test method is urged to use caution when determining fluoride (see Note 2). If theuser wishes to be certain of good results and has interfering anions present when determining fluoride, the eluent can be diluteduntil separation of fluorid
43、e and carbonate is accomplished. This will cause an increase in retention time for anions such as sulfateto elute. Additional steps to avoid the water dip are mentioned in Appendix X1.7. Apparatus7.1 Ion ChromatographThe ion chromatograph should have the following components assembled, as shown in F
44、ig. 2:47.1.1 Eluent and Regenerant Containers.7.1.2 Eluent Pump, capable of delivering 1 to 3 mL/min of eluent at a pressure of up to 2000 psig. psi.7.1.3 Guard ColumnAnion exchange column, typically of the same anion exchange material used in the separator column.The purpose of this column is to pr
45、otect the analytical column from particulate matter and irreversibly retained materials.4Available from Dionex Corp., 1228 Titan Way, Sunnyvale, CA 94086. An equivalent may be used. Other manufacturers components may provide equivalent data.D4327 1137.1.4 Analytical ColumnAnion exchange column capab
46、le of separating chloride from the injection void volume, as well asresolving the anions chloride through sulfate.NOTE 3Any analytical column may be used. However, the user should be able to achieve the resolution and separation as shown in Fig. 1.7.1.5 Suppressor DeviceA suppressor device based upo
47、n cation-exchange principles. In this method a membrane-basedself-regenerating suppressor device was used. An equivalent suppressor device may be used provided that comparable methoddetection limits are achieved and that adequate baseline stability is attained. A suppressor device based upon cation-
48、exchangeprinciples. In this method a membrane-based self-regenerating suppressor device was used. An equivalent suppressor device maybe used provided that comparable method detection limits are achieved and that adequate baseline stability is attained. Anelectrolytic suppressor device can be used wh
49、ich does not require the addition of an acid but is a plug in electrolytic device. Thesuppressed eluent (water) is simply recirculated from the conductivity cell back to the electrolytic suppressor to back flush thesuppressor device. Alternative pumps are also typically not required.7.1.6 DetectorA low-volume, flow through, temperature-compensated electrical conductivity cell equipped with a metercapable of reading from 0 to 1000 S/cm on a linear scale or greater if applicable.7.1.7 Recorder, Integrator, ComputerA device compatible with t
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