1、Designation: E 2409 04Standard Test Method forGlycol Impurities in Mono-, Di-, Tri- and Tetraethylene Glycol(Gas Chromatographic Method)1This standard is issued under the fixed designation E 2409; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last 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. Scope1.1 This test method describes the gas chromatographicdetermination of glycol impurities in Mon
3、o-, Di- Tri- andTetraethylene Glycol (MEG, DEG, TEG and TeEG) in therange of 5 to 3000 mg/kg.1.2 The values stated in SI units are to be regarded as thestandard.1.3 Review the current Material Safety Data Sheets (MSDS)for detailed information concerning toxicity, first aid proce-dures, and safety pr
4、ecautions.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 practices and determine the applica-bility of regulatory limitations prior to use.2. Re
5、ferenced Documents2.1 ASTM Standards:2E 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial ChemicalsE 300 Practice for Sampling Industrial ChemicalsE 1064 Test Method for Water in Organic Liquids byCoulometric Karl Fischer Titration2.2 Other Document:Man
6、ufacturers instruction manuals of gas chromatographand digital integration system used.3. Summary of Test Method3.1 A portion of the test sample is analyzed by temperature-programmed, capillary gas chromatography over a DB-waxcolumn, using flame ionization detection. For quantification theExternal S
7、tandard Technique or the Internal Standard (Marker)Technique, using 1,4-butanediol as marker, are applied. Whenapplying the Internal Standard Technique, the standard additiontechnique is used to eliminate the effect of other impuritiespresent in the glycols. For this purpose, a blank glycol is used,
8、as 100 % pure glycol samples are not available.4. Significance and Use4.1 Knowledge of the impurities is required to establishwhether the product meets the requirements of its specifica-tions.5. Apparatus5.1 Gas Chromatograph(s), provided with a sample splitteror on-column injection, flame ionizatio
9、n detector andtemperature-programming facilities. Optional are pressure pro-gramming and autosampler facilities. The instrument must besuitable for analysis according to the operating instructionsgiven in Table 1.5.1.1 ColumnsThe analytical column used must com-pletely separate MEG, DEG, TEG, TeEG,
10、PentaEG (Penta-ethylene Glycol) and 1,4-butanediol. Figs.A1.1,A1.2 andA1.3show examples of chromatograms conforming to the require-ments.5.2 Digital Integration Equipment:5.3 Analytical Balance, readability 0.1 mg, calibrated. Cali-brate and verify at regular intervals.5.4 Crimp Top Vials,1mLand5mL.
11、5.5 Crimper/De-capper, for capping and de-capping thevials.5.6 Micro Syringes,10L.5.7 Bottles, 50 mL, with screw cap.6. Reagents and Materials6.1 Purity of ReagentsUnless otherwise indicated, it isintended that all reagents shall conform to the specifications ofthe Committee onAnalytical Reagents of
12、 theAmerican Chemi-cal Society where such specifications are available.3Othergrades may be used, provided it is first ascertained that thereagent is of sufficiently high purity to permit its use withoutlessening the accuracy of the determination.1This test method is under the jurisdiction of ASTM Co
13、mmittee E15 onIndustrial and Specialty Chemicals and is the direct responsibility of SubcommitteeE15.02 on Product Standards.Current edition approved Oct. 1, 2004. Published November 2004.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service
14、astm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American
15、Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmocopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
16、9428-2959, United States.6.2 Calibration Standards:6.2.1 Mono-ethylene Glycol (MEG), minimum purity99.5 % mass (m/m).6.2.2 Di-ethylene Glycol (DEG), minimum purity 99.5 %mass (m/m).6.2.3 Tri-ethylene Glycol (TEG), minimum purity 99.5 %mass (m/m).6.2.4 Tetra-ethylene Glycol (TeEG), of maximum puritya
17、vailable.6.2.5 Penta-ethylene Glycol (PentaEG), of maximum purityavailable.6.3 1,4-Butanediol, internal standard (marker) minimumpurity 97 % mass (m/m), if necessary.6.4 Ethylene Glycol Quality Control Sample, fiber gradeMEG, DEG, TEG or TeEG (only required if maintaining acontrol chart, see 10.4).
18、Store nitrogen capped at a temperaturebetween 0 and 5C. Warm to ambient temperature before use.6.5 Water, HPLC grade.6.6 Solutions:6.6.1 Internal Standard SolutionWeigh about 0.15 g 1,4-butanediol (m1) to the nearest 0.1 mg into a 50 mL bottle. Addultra-pure water up to a total mass of 50 g (m2), we
19、ighing to thenearest 0.1 mg. Calculate the concentration of this solution tothe nearest 0.1 mg/kg, or6.6.2 External Standard Solution, of accurately knownMEG, DEG, TEG, and TeEG content, to be used as externalstandard (see 9.3).7. Sampling, Test Specimens, and Test Units7.1 Follow the relevant instr
20、uctions for sampling as given inPractice E 300.8. Preparation of Apparatus8.1 Gas Chromatograph(s) and Column(s)Check the per-formance of the gas chromatograph and column as described inSection 9.9. Calibration and Standardization9.1 Two methods of quantification may be employed: theInternal Standar
21、d (Marker) Technique or the External StandardTechnique.9.2 Internal Standard Technique:9.2.1 Prepare calibration solutions, containing 500, 1000and 2000 mg/kg of each of the glycol components to bedetermined, by adding the relevant calibration standard (see6.2) to a blank sample of the glycol being
22、analyzed. Calculatethe exact concentration of each glycol component (c1) in thecalibration solutions.9.2.2 Weigh 0.5 g of each calibration solution (m3)tothenearest 0.1 mg, into separate 5-mL vials. Add, also weighed tothe nearest 0.1 mg, 0.5 g internal standard solution (see 6.6.1;m4) and add HPLC
23、grade water up to a total mass ofapproximately 5 g. Cap the vials and mix thoroughly.9.2.3 Prepare a blank calibration solution by weighing 0.5 gblank sample of the glycol being analyzed (m5), weighed to thenearest 0.1 mg, into a 5-mL vial. Add 0.5 g internal standardsolution (see 6.6.1; m6), also w
24、eighed to the nearest 0.1 mg,and add HPLC grade water up to a total mass of approximately5 g. Cap the vial and mix thoroughly.9.2.4 Calibrate separately for each impurity in MEG, DEG,TEG or TeEG by using the Internal Standard (Marker) Tech-nique.9.2.5 Fill a 1-mL sample vial with the calibration sol
25、utionfrom the 5-mL vial (see 9.2.2 and 9.2.3). Close the vial bymeans of an aluminum crimp cap.9.2.6 Analyze each calibration solution and the blank solu-tion using the operating parameters given in Table 1. Injecteach solution at least twice and calculate the average peakareas for each of the calib
26、ration solutions. Apply digitalintegration equipment for measuring the peak areas.9.2.7 For each chromatogram, calculate the system responsefactor (f) of each of the components as described in 9.2.8through 9.2.10.9.2.8 Calculate the amount of internal standard (1,4-butanediol) added to the calibrati
27、on solution:Mass of Internal Standard m7!,g5m43 m1m2(1)where:m1= mass of 1,4-butanediol in internal standard solution(6.6.1), g,m2= total mass of internal standard solution (6.6.1), g, andm4= mass of internal standard solution added, g.9.2.9 Calculate the amount of internal standard (1,4-butanediol)
28、 added to the blank solution:Mass of Internal Standard m8!,g5m63 m1m2(2)where:m6= mass of internal standard solution added (9.2.3), g.TABLE 1 Typical Operating Parameters for the GC Analysis ofGlycol Impurities in MEG, DEG, TEG or TeEGColumnAType Capillary wide-boreMaterial Fused silicaLength 3 I.D.
29、 15 m 3 0.53 mmStationary Phase DB-WaxFilm Thickness 1 mDetector SystemType FIDSensitivity The ratio of the signal to the noise level must be at least2:1 at a concentration of 5 mg/kg DEG in MEGTemperaturesColumn Oven 0.05 min at 70CProgrammed from 70 to 230C at 25C/min10 min at 230CDetector 250CCar
30、rier Gas Helium or NitrogenCalibration see Section 9Injected Volume 0.2 L (on-column injection), or0.5 L up to 1 L (using split injection technique)Split Ratio 1:10 or appropriate split ratio to allow adequate sensitivityas defined under Detector System (only if split injectiontechnique is used)AThe
31、 above-mentioned DB-Wax column is available from Ji!WComp;i!1 WBlank;i!3106gg(4)where:Ci= the concentration of each glycol componentin the calibration standard of interest,i = the calibration standard of interest,W(Comp;i)= weight (g) of glycol component added to thecalibration standard of interest,
32、 andW(Blank;i)= weight (g) of blank glycol added to thecalibration standard of interest.9.3.2 Analyze each calibration solution and the blank solu-tion using the operating parameters given in Table 1. Injecteach solution at least twice.9.3.2.1 Prepare a plot of area counts of the glycol compo-nent (
33、y-axis) versus the concentration of the glycol component(mg/kg) added to the standard of interest (x-axis). Using acomputer program, determine the best-fit line through the datausing linear regression analysis. The relationship betweenconcentration and peak area will be linear. Record the interceptv
34、alue (concentration; mg/kg) where the resulting line crossesthe x-axis (y = 0). Apply digital integration equipment formeasuring the peak areas.9.3.2.2 Calculate the corrected concentration (mg/kg) of theglycol component in each calibration standard as follows:Corrected Ci5 Ci1 Y (5)where:Corrected
35、Ci= the corrected concentration (mg/kg) of theglycol component in each calibration stan-dard of interest,Ci= the concentration (mg/kg) of the glycolcomponent added to the calibration stan-dard of interest, andY = absolute value of the concentration of blankglycol determined from the linear regres-si
36、on graph (intercept value) for each cali-bration standard.9.3.3 For each chromatogram, calculate the system responsefactor (f) of each of the glycol components by means of thefollowing equation:f 5Corrected CiAi(6)where:Corrected Ci= concentration of component in externalstandard solution, mg/kg, an
37、dAi= peak area of component, arbitrary units.9.3.3.1 Calculate the mean of the response factors for eachof the glycol components. If the individual factors differ bymore than 5 % from the mean response factor, repeat themeasurement of the respective calibration solution.NOTE 1Many gas chromatographs
38、 have the ability to calculate acalibration graph automatically after measuring the calibration solutionsand subsequently to show the concentration of the component beingmeasured directly on a display. In such cases, no calibration graphs needto be constructed. It is, however, recommended to verify
39、the calibrationprocedure of the instrument and to establish the characteristics of thecalibration graph according to suitable regression analysis software.10. Procedure10.1 Internal Standard Technique:10.1.1 Weigh a test portion of 0.5 g (m9), weighed to thenearest 0.1 mg, into a 5-mL vial.NOTE 2Thi
40、s method is for the determination of glycol impurities inthe range of 5 to 3000 mg/kg. Higher levels of glycol impurities ( 5000mg/kg) can be determined, if the intake is adjusted as follows:Mass Intake Sample, g 52000c3 0.5 (7)TABLE 2 External Standard Recommended WeightsStandard #Target Weight ofG
41、lycol Component,6 0.0001 gTarget Weight ofHigh Purity Blank Glycol,6 0.1 g200 mg/kg 0.010 50500 mg/kg 0.025 501000 mg/kg 0.050 50E2409043where:c = the expected maximum concentration of component inthe sample, mg/kg.10.1.2 Add 0.5 g internal standard solution (m10), weighedto the nearest 0.1 mg, and
42、add HPLC grade water up to a totalmass of approximately 5 g and weigh. Close the vial and mixthoroughly.10.1.3 Fill a 1-mL sample vial with the test solution. Closethe vial by means of an aluminum crimp-cap.10.1.4 Analyze the test solution using the operating param-eters given in Table 1. Examples o
43、f the chromatograms areshown in Figs. A1.1, A1.2 and A1.3 Apply digital integrationequipment for measuring the area of the peaks.10.2 External Standard TechniqueWhen applying the ex-ternal standard technique, analyze the test sample using theoperating parameters given in Table 1. Sample dilution, wi
44、ththe sample glycol, may be necessary if the component ofinterest is beyond the range of the method. Apply digitalintegration equipment for measuring the area of the peaks.10.3 Determination of Water ContentIf it is required tocalculate and report the purity of the sample, determine thewater content
45、 in % mass (m/m) according to Test MethodE 1064.10.4 Quality ControlIt is recommended that a controlchart for the concentration of the impurities in the glycolquality control sample be established and maintained accordingto generally accepted guidelines.4Measure the control sampleeach time a test sa
46、mple(s) is tested, using the same calibrationprocedure as applied for the sample. If the measured valueexceeds the action limit of the control chart, take appropriateaction before proceeding with sample tests.11. Calculation11.1 Internal Standard Technique:11.1.1 Calculate the amount (m11) of intern
47、al standard(1,4-butanediol) added to the test sample by means of thefollowing equation:Mass of Internal Standard m11!,g5m103 m1m2(8)where:m10= mass of internal standard solution added, (10.1.2), g,m1= mass of 1,4-butanediol in internal standard solution(9.3.1), g, andm2= total mass of internal stand
48、ard solution (9.3.1), g.11.1.2 Calculate the concentration of each component ofinterest in the sample by means of the following equation:Glycol Component, mg/kg 5f 3 m113 A5m93 A63 106(9)where:A5= peak area of the component, arbitrary units,A6= peak area of internal standard, same arbitrary units,f
49、= relative response factor of component of interest, asobtained in 9.2.1,m9= mass of sample, that is, without internal standard,(10.1.1), g, andm11= mass of internal standard in test solution, as obtainedin 11.1.1, g.NOTE 3If the concentration of the calculated glycol component isrequired to be expressed in % mass (m/m), divide the result obtainedabove by a factor of 104.11.2 External Standard Technique:11.2.1 Obtain the concentrations of the glycol impurities inthe test sample in mg/kg, as presented by the software of theapplied gas chromatograph (see Note 1
