1、Designation: E2469 16Standard Test Method forChloride in Mono-, Di- and Tri-ethylene Glycol by IonChromatography1This standard is issued under the fixed designation E2469; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 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 method covers the determination of inorganicchloride (chloride ion) in monoethylene glycol (MEG), dieth-yl
3、ene glycol (DEG) and triethylene glycol (TEG) in the rangeof 0.01 to 1.0 mg/kg by ion chromatography (IC).1.2 Ethylene glycol can be analyzed directly by this testmethod without any sample preparation or diluted with highquality deionized water if an autosampler is used and dilutionis necessary (tha
4、t is, 50:50 or other suitable ratio).1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3.1 The exception is the additional information of (psi) in9.3.3, 11.1.1, and 11.2.1.1.4 Review the current Safety Data Sheets (SDS) for
5、de-tailed information concerning toxicity, first-aid procedures andsafety precautions.1.5 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 practices a
6、nd to determine theapplicability of regulatory limitations prior to use. For specifichazard statements, see Section 9.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate A
7、nalyticalMeasurement System PerformanceE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)3E300 Practice for Sampling Industrial Chemicals3. Summary of Test Method3.1 An aliquot of the glycol sample is injected d
8、irectly(manually) or diluted (via autosampler) into an ion chromato-graph consisting of an injector with a fixed sample loop, twoanion exchange columns (guard and separator column), ananion suppressor and a conductivity detector. Ions are sepa-rated based on their affinity for the ion exchange sites
9、 of theresin with respect to the resins affinity for the eluent. Thesuppressor increases the sensitivity of the test method by bothincreasing the conductivity of the analytes and decreasing theconductivity of the eluent. The suppressor converts the eluentand the analytes to the corresponding hydroge
10、n form acids.The chloride is detected by conductivity detection and identi-fied by retention time. Quantitation is by peak area using anexternal standard calibration curve. Instructions are providedfor two equivalent IC systems.4. Significance and Use4.1 This test method provides for the quantitativ
11、e determi-nation of inorganic chloride (chloride ion) in monoethyleneglycol (MEG), diethylene glycol (DEG) and triethylene glycol(TEG) using ion chromatography with conductivity detection.The analysis time is less than 5 min with little or no samplepreparation required. Conductivity detection is a u
12、niversaldetection mode and is linear over the range of the method.Acceptable levels of chloride in polyester-grade and low-conductivity-grade MEG vary with the manufacturers speci-fications but are normally in the low mg/kg range. Knowledgeof the chloride content in polyester-grade and low-conductiv
13、ity-grade MEG is required to establish whether theMEG product meets specification requirements.4.2 Glycols have high viscosities and a dilution with highquality deionized water may be required depending on thecapability of the autosampler, if used, to deliver the injection.1This test method is under
14、 the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicals and is the direct responsibility of SubcommitteeE15.02 on Product Standards.Current edition approved Jan. 1, 2016. Published March 2016. Originallyapproved in 2006. Last previous edition approved in 2008 as E2469 08a. DOI:1
15、0.1520/E2469-16.2For 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 ASTM website.3The last approved version of this historical
16、 standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1All standards and samples, whether diluted or not should betreated in the same man
17、ner.5. Interferences5.1 The identification of chloride is based on retention time.Interferences can be caused by ionic substances with retentiontimes similar to that of chloride. If the eluent conditions arechanged or the column capacity changes, it is possible thatother anions may coelute with chlo
18、ride and cause an interfer-ence.5.2 Any anion that elutes after chloride under the analysisconditions used in the test method may cause an interference ifthe run time of the method isnt long enough to include thatanion. When the run time of a method is too short, a late elutinganion from one analysi
19、s may be detected during the nextanalysis and cause an interference if it elutes at the same timeas chloride. Carbonate, if present in a sample, may cause aninterference in IC systems using hydroxide eluent (like Con-figuration B) if the run time of the analysis is not long enoughto include the carb
20、onate peak. The elution time of carbonateunder the analysis conditions used in this test method isdirectly related to the amount of carbonate in the sample. Thehigher the concentration of carbonate in a sample, the faster thecarbonate elutes from the column.5.3 Method interferences can be caused by
21、the contamina-tion of glassware, eluent and reagents with chloride. Care mustbe taken to ensure glassware and apparatus are free of chloride.The use of latex gloves is recommended to prevent chloridecontamination while handling samples and reagents.5.4 In an IC system with an electrolytic membrane b
22、asedsuppressor operated in the recycle mode, the eluent is recycledback through the suppressor after it exits the conductivity cellto provide a source of water for electrolytic generation ofhydronium ions for the regenerant. Using this systemconfiguration, there is an interference caused by the glyc
23、olsample as it passes back through the suppressor. This interfer-ence appears as a large broad peak that upsets the baselineduring the time chloride elutes from the column. Accuratequantitation of chloride is very difficult if not impossible withthis interference present. To avoid this interference,
24、 an externalsupply of reagent water is used as the source of hydronium ionsfor the regenerant. In the external water mode, water flowscountercurrent to the eluent through the suppressor. The watercan be pressurized or pumped through the suppressor toachieve the required flow rate.5.5 No other direct
25、 interferences have been observed in theuse of this test method. If results are suspect based on theanalytical history of the product, the data should be confirmedby an alternate test method.6. Apparatus6.1 Analytical Balance, capable of weighing 200 g to thenearest 0.0001 g. (See Note 1.)6.2 Pipett
26、es, capable of measuring from 100-L to 10-mL.(See Note 1.)NOTE 1The accuracy of balances and pipettes should be confirmed ona regular basis and documentation of the check should be kept.6.3 Ion Chromatograph, Configuration A (Bottled EluentSystem - Carbonate-Based) (see Note 2)Analytical instru-ment
27、 with all the required accessories including an eluentpump, temperature-controlled low volume ( 2 L) conductiv-ity cell, conductivity detector, PEEK tubing, and a PEEKinjection valve with a fixed sample loop. An auxiliary regen-erant pump or pressurized 4-L reagent bottle is required forexternal reg
28、enerant delivery. Autosampler (optional). The in-strument must be suitable for analysis according to the oper-ating conditions given in 11.1.NOTE 2The ion chromatograph (Configuration A) uses a carbonatebased eluent system in which the eluent is prepared by the analyst fromanalytical grade reagents
29、or commercially available concentrated carbon-ate solutions. There is more variability in the retention time of chloridewith this type of system as a result of variations in the concentration of theeluent prepared by analysts. This is the oldest and most commonly used ICsystem.6.3.1 Anion Exchange G
30、uard Column (for Carbonate-BasedEluent), for protection of the analytical column from stronglyretained components and organics. Better separations areobtained with the additional plates of the guard column.6.3.2 Anion Exchange Separator Column (for Carbonate-Based Eluent), capable of producing separ
31、ation of the chlorideequivalent to or better than that shown in Fig. 1.6.3.3 Anion Suppressor, an electrolytic self-regeneratingmembrane suppressor, micromembrane suppressor or equiva-lent suppressor capable of lowering the background conduc-tance of the eluant to a level that allows the method dete
32、ctionlimit to be achieved.6.3.4 Chromatography Data System, for data acquisitionand data processing.6.4 Ion Chromatograph, Configuration B (Eluent Genera-tion System - Hydroxide Eluent) (see Note 3)Analyticalinstrument with all the required accessories including an eluentpump, temperature controlled
33、 low volume ( 2 L) conductiv-ity cell, conductivity detector, PEEK tubing, PEEK injectionvalve with a fixed sample loop and electrolytic eluent genera-tion module. An auxiliary regenerant pump or pressurized 4-Lreagent bottle is required for external regenerant delivery.Autosampler (optional). The i
34、nstrument must be suitable foranalysis according to the operating conditions given in 11.2.NOTE 3The IC system (Configuration B) uses on-line electrolyticeluent generation to produce a hydroxide eluent. The hydroxide eluent isgenerated from reagent water using an eluent generator cartridge. Theconce
35、ntration of hydroxide eluent is very reproducible, so the retentiontime for chloride is less variable than with a carbonate eluent. This newertechnology for eluent generation eliminates the variability of eluentpreparation by an analyst. It also eliminates the problems with eluentaging (weakening) a
36、nd contamination.NOTE 4The IC system in Configuration B uses on-line electrolyticeluent generation to produce the eluent. The type of eluent produceddepends on the eluent generator cartridge used with the IC system. Thereare four types of eluent generator cartridges including potassiumhydroxide, car
37、bonate-bicarbonate, lithium hydroxide and sodium hydrox-ide. For this test method the potassium hydroxide eluent cartridge isrecommended for use with hydroxide selective columns. The carbonate-bicarbonate eluent cartridge and eluent pH modifier can be used withcarbonate selective columns (6.3.1 and
38、6.3.2) if the analyst prefers on-linecarbonate-bicarbonate eluent generation.E2469 1626.4.1 Anion Exchange Guard Column (for HydroxideEluent), for protection of the analytical column from stronglyretained components and organics. Better separations areobtained with the additional plates of the guard
39、 column.6.4.2 Anion Exchange Separator Column (for HydroxideEluent), capable of producing separation of chloride equivalentto or better than that shown in Fig. 2.FIG. 1 Representative Sample Chromatogram Obtained Using the Conditions Outlined in 11.1 (Configuration A)FIG. 2 Representative Sample Chr
40、omatogram Obtained Using the Conditions Outlined in 11.2 (Configuration B)E2469 1636.4.3 Anion Exchange Trap Column (for Hydroxide Eluent),electrolytic continuously regenerated trap column or equivalenttrap column capable of removing anionic impurities fromreagent water used with the eluent generati
41、on cartridge.6.4.4 Anion Suppressor, an electrolytic self-regeneratingmembrane suppressor, micromembrane suppressor or equiva-lent suppressor capable of lowering the background conduc-tance of the eluant to a level that allows the method detectionlimit to be achieved.6.4.5 Eluent Generator Cartridge
42、, capable of producingcarbonate-free potassium hydroxide.46.4.6 Chromatography Data System, for data acquisitionand data processing.6.4.7 Chromatography Operating System, capable of con-trolling the current required for eluent generation and trapcolumn regeneration.6.5 Volumetric Glassware, 100-mL,
43、1-L, and 2-Lvolumetricflask. (See Note 5.)6.6 Plastic Cups with Lids, 120 mL. (See Note 5.)6.7 Weigh Dish, small disposable polystyrene. (See Note 5.)6.8 Bottles with Caps, 125-mL Nalgene low density poly-ethylene (LDPE) narrow mouth. (See Note 5.)6.9 Plastic Syringe, 10-mL with Luer-Lok Tip. (See N
44、ote5.)NOTE 5Care should be taken to ensure glassware, reagents andapparatus are free of chloride contamination.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications o
45、f the Committee onAnalytical Reagents of the American Chemical Society (ACS)where such specifications are available.5Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 High-
46、Purity WaterUnless otherwise indicated, refer-ences to water shall be understood to mean reagent water asdefined by Type II of Specification D1193. It is recommendedthat all water be filtered through a 0.2-m filter. For eluentpreparation, it is recommended to degas the water by spargingwith helium o
47、r vacuum degassing and sonication.7.3 Sodium Chloride, ACS reagent grade.7.4 Chloride Quality Assurance Check Standard, anindependent, certified 10 g/mL chloride standard (not madefrom sodium chloride in 7.3), may be purchased commercially.7.5 Sodium Carbonate (Configuration A), ACS reagentgrade.7.6
48、 Sodium Bicarbonate (Configuration A), ACS reagentgrade.7.7 Sodium Carbonate Concentrate (Configuration A),0.5 M sodium carbonate, commercially available.7.8 Sodium Bicarbonate Concentrate (Configuration A),0.5 M sodium bicarbonate, commercially available.7.9 Monoethylene Glycol (MEG) (High Purity),
49、 with lowconcentrations of impurities.7.10 Diethylene Glycol (DEG) (High Purity), with lowconcentrations of impurities.7.11 Triethylene Glycol (TEG) (High Purity), with lowconcentrations of impurities.NOTE 6 Impurities in high-purity MEG, DEG or TEG used forpreparation of the chloride working standards or for sample dilutionshould not exceed 0.01 mg/kg. This information should be provided by thesupplier or determined by the analyst before use.7.12 Sulfuric Acid (for use with anion micromembranesuppressor), concentrated sulfuric acid (95 to 98 %).7.13 Anion Regene
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