1、Designation: E 611 03Standard Test Methods forLow Concentrations of Diethlyene Glycol in Ethylene Glycolby Gas Chromatography1This standard is issued under the fixed designation E 611; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods are intended primarily for theanalysis of mixtures of ethylene and diethylene glycol
3、s inwhich the diethylene glycol concentration is 0.1 % or less.Both test methods should be applicable to higher concentra-tions of diethylene glycol, but precision and bias estimateshave been obtained only for 0.05 to 0.1 % diethylene glycol.NOTE 1Test Methods E 202 describe another gas chromatograp
4、hictest method applicable to mixtures of ethylene, diethylene, and triethyleneglycols and mixtures of propylene, dipropylene, and tripropylene glycolsin which one of the glycols is the principal component and the other twoare present in concentrations of 0.1 to 1 % each.1.2 The two test methods are
5、given as follows:SectionsTest Method ANonderivative Method 5 to 13Test Method BDerivative Method 14 to 221.3 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
6、 health practices and determine the applica-bility of regulatory limitations prior to use. For a specificwarning statement, see 15.1.5.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing
7、 of Industrial ChemicalsE 202 Test Methods for Analysis of Ethylene Glycols andPropylene Glycols3. Significance and Use3.1 Either test method may be used to determine theconcentrations of diethylene glycol in ethylene glycol. Theconcentrations of the components are obtained by a normal-ization techn
8、ique, based on the assumption that all componentsare eluted under the conditions used. If all components shouldnot be eluted, the calculated concentrations will be erroneouslyhigh, with the major component showing the most significantabsolute error. Since water is not detected by these procedures,th
9、e results are on a water-free basis. Water may be determinedin accordance with the applicable sections of Test MethodsE 202 and the gas chromatographic results corrected for thewater concentration.3.2 Both test methods are currently in industrial use. TestMethod A is the simpler of the two test meth
10、ods because it doesnot require the preparation of derivatives prior to gas chro-matographic analysis. The results obtained by Test Method Aare slightly more accurate than those obtained by Test MethodB. With respect to precision there is no significant differencebetween the two test methods. Test Me
11、thod B has beenreported to be suitable also for the analysis of a wide variety ofglycol ethers, but this use is beyond the scope of this standard.4. Purity of Reagents4.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to t
12、he specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available.3Other grades may be used, pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determi
13、nation.4.2 Unless otherwise indicated, references to water shall beunderstood to mean Type II or III reagent water conforming toSpecification D 1193.TEST METHOD ANONDERIVATIVE METHOD5. Summary of Test Method5.1 The sample is injected into a gas chromatographiccolumn. The components are separated as
14、they pass through1These test methods are under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicals and are the direct responsibility of Subcommit-tee E15.01 on General Standards.Current edition approved Oct. 1, 2003. Published December 2003. Originallyapproved in 1977. Discon
15、tinued September 1996 and reinstated as E 611 03.2For 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.3Reagent Che
16、micals, American Chemical Society Specifications, Am. ChemicalSoc., Washington, DC. For suggestions on the testing of reagents not listed by theAmerican Chemical Society, see Analar Standards for Laboratory Chemicals, BDHLtd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormu
17、lary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the column with helium carrier gas, their presence in theeffluent is detected by a flame ionization detector, and recorde
18、das a chromatogram. The areas under the peaks due to thesample components are corrected by applying appropriatecalibration factors to obtain the composition of the sample ona weight percentage basis.6. Apparatus6.1 Gas Chromatographic Instrument having the followingminimal characteristics (see Table
19、 1).6.1.1 Sample Injection Port, with heater characteristicsnecessary for operation at 210C.6.1.2 Column Oven, capable of isothermal operation at168C.6.1.3 Detector, of conventional flame ionization type, ca-pable of operating at 168C. A conventional thermal conduc-tivity detector can be used, but s
20、ensitivity will be reduced andwater may be detected as a peak eluting with the pressure peakdue to sample injection, depending upon the concentration ofwater. The precision and bias statements in Section 13 are forflame ionization detectors.6.1.4 Recorder, 0 to 1-mV range, that 1-s full scale deflec
21、-tion with a chart speed of approximately12-in./min (12.7mm/min) or other convenient speed that will produce asatisfactory chromatogram, and an attenuator switch to changethe recorder range as required to keep the chromatogram onscale.NOTE 2On instruments using electronic integration the attenuation
22、feature is not required.6.1.5 Column, 50 in. (1270 mm) long,316 in. (4.8 mm) inoutside diameter with a wall thickness of 0.030 in. (0.76 mm)for copper or 0.020 in. (0.51 mm) for stainless steel construc-tion; packed with 10 % polyethylene glycol on orange calci-nated diatomite with dimethyldichloros
23、ilane, DMCS, 60/80mesh.6.1.6 Microsyringe, 10-L capacity.6.1.7 Copper or Stainless Steel Tubing,316 in. (4.8 mm) inoutside diameter with a wall thickness of 0.030 in. (0.76 mm)for copper or 0.020 in. (0.51 mm) for stainless steel.NOTE 3The copper tubing should be sealed, refrigeration grade. If thes
24、eal has been broken, clean the copper tubing with an acetone wash anddry with nitrogen before filling. Stainless steel tubing should be pre-washed with successive volumes of 10 % HCl, distilled water, acetone,methylene chloride, and dried with nitrogen.7. Reagents and Materials7.1 Air, compressed.7.
25、2 Orange Calcinated Diatomite with Dimethyldichlorosi-lane, 60/80 mesh.7.3 Ethylene Glycol and Diethylene GlycolSee Section 9for purity requirements.7.4 Helium (He).7.5 Hydrogen (H2).7.6 Methylene Chloride (Dichloromethane) (CH2Cl2).7.7 Polyethylene Glycol, 20 000 molecular weight.8. Preparation of
26、Chromatographic Column8.1 Dissolve 20 g of the polyethylene glycol in approxi-mately 200 mL of CH2Cl2with gentle warming to aid solution.Add 180 g of orange calcinated diatamite with dimethyldichlo-rosilane, DMCS, and sufficient CH2Cl2to form a slurry, andmix well, making certain that all particles
27、are wetted. Evapo-rate the CH2Cl2by heating gently over a steam bath in a fumehood until the mixture is dry. Frequent stirring of the slurryduring the drying operation is necessary to obtain a uniformcoating. The use of a vacuum rotary evaporator will shorten thetime required for drying.8.2 Screen t
28、he dried packing through a 50-mesh (300-mscreen opening) and an 80-mesh (180-m screen opening)screen to remove any lumps and fines. Fill a 50-in. (1270-mm)section of316-in. (4.8-mm) outside diameter copper or stainlesssteel tubing with the screened packing retained on the 80-meshscreen. Gently vibra
29、te the tubing during packing to ensureuniform packing. Use borosilicate glass wool for plugs in theends of the column. Columns packed using vacuum or byblowing the packing into the tubing are generally unsatisfac-tory.8.3 Condition the column prior to use by placing the columnin the chromatograph in
30、 accordance with 10.1, but do notconnect the column to the detector. Pass helium through thecolumn at 100 mL/min during the conditioning.9. Calibration Factors9.1 In order to obtain the composition of the sample in termsof weight percent, multiply the areas associated with theTABLE 1 Instrument Para
31、meters, Method ANonderivativeInstrument Varian Aerograph. Model 204, equipped with flame ionizationdetectorsAStrip-chart recorder 0-1 mV rangeChart speed12 in. (12.7 mm)/minColumn 50 in. (1270 mm) of316-in. (4.8-mm) outside diameter copper orstainless steel tubing packed with 10 % polyethylene glyco
32、l.20 000 molecular weight, on Chromosorb G, DMCS, 60/80 meshColumn temperature 168CCarrier gas helium at 100 mL/minHydrogen flow rate 40 mL/minAir flow rate 400 mL/minInjection port temperature 210CDetector block temperature 168CSample size 2 LInjection time 28 sAThe parameters in this table apply t
33、o a Varian Aerograph, Model 204, manufactured by Varian Div., 611 Hansen Way, Palo Alto, CA 94303. Any similar instrument maybe used for this method with appropriate modifications of the parameters.E611032components by an appropriate calibration factor. These factorsare obtained from mixtures of kno
34、wn composition, and shouldbe determined for each apparatus. The calibration factors maybe obtained using standards prepared from “hearts cuts” fromthe distillation of each of the glycols, or from commercialgrades of each glycol as described in the following testmethods. For highest accuracy, use gly
35、cols obtained from“hearts cuts.” Check the calibration factors periodically orwhenever there is evidence of a change in the column orinstrument.9.2 Calibration Method 1:9.2.1 Purify the commercial grade of each glycol needed bycareful fractionation in glass at reduced pressure, discardingthe first 3
36、0 % and retaining the next 30 % as the “hearts cuts.”Analyze these fractions as described in Section 10 to be surethey are free of other homologues of the glycol.9.2.2 Prepare a standard mixture of these glycols whosecomposition approximates that of the glycol to be analyzed.The composition of the s
37、tandard should be known to thenearest 0.001 %. Correct the composition for any water presentusing the equation in 11.2.4. Determine the water content asdescribed in the applicable section of Test Methods E 202.9.2.3 Obtain at least two chromatograms of the standardmixture as described in Section 10
38、and calculate the averagearea percent for each of the glycols present in accordance with11.2.1. Do not include any areas associated with the pressurepeak in calculating the area percentages. Using the weightpercentages in the standard mixture and the average areapercentages, calculate the factor for
39、 diethylene glycol asdescribed in 11.1.1. Assume a calibration factor of unity for theethylene glycol in the base ethylene glycol standard mixture.9.3 Calibration Method 2:9.3.1 For routine analyses, high-purity, commercial gradesof each glycol may be used. If the gas chromatographicanalysis as desc
40、ribed in Section 10 indicates that the concen-tration of the ethylene glycol in the diethylene glycol to beadded to the base ethylene glycol in the standard mixture doesnot exceed 0.2 area %, the concentration of the impurity isinsignificant at the concentration levels included in the scope ofthis t
41、est method. The base ethylene glycol should contain lessthan 0.05 area % diethylene glycol.9.3.2 Prepare a standard mixture of the glycols whosecomposition approximates that of the glycol to be analyzed.The composition of the standard mixture should be known tothe nearest 0.001 %. Correct the compos
42、ition for any waterpresent using the equation in 11.2.4. Determine the watercontent as described in the applicable section of Test MethodsE 202. If the concentrations of the ethylene glycol in thediethylene glycol added to the base ethylene glycol in thestandard mixture does not exceed 0.2 area %, t
43、he concentrationof the impurity is insignificant at the concentration levelsincluded in the scope of this method. The base ethylene glycolshould contain less than 0.1 area % diethylene glycol.9.3.3 Obtain at least two chromatograms of the standardmixture and of the base ethylene glycol in accordance
44、 with10.2 and calculate the average area percent for each of theglycols present in accordance with 11.2.1. Do not include anyareas associated with the pressure peak in calculating the areapercentages. Using the weight percent of diethylene glycoladded to the ethylene glycol and the average area perc
45、entagesfor the glycols calculate the calibration factor for the diethyleneglycol in accordance with 11.1.2. Assume the calibration factorof unity for the ethylene glycol in the base ethylene glycol andthe standard mixture.10. Procedure10.1 Mount the column in the chromatograph, and adjustthe operati
46、ng conditions in accordance with the parametersgiven in Table 1 (see Note 4). Allow sufficient time for theinstrument to reach equilibrium as indicated by a stable baseline on the chart at the maximum sensitivity setting to be used.NOTE 4The instrument parameters given in Table 1 were developedfor t
47、he indicated instrument. The use of other instruments will probablyrequire some adjustment of column temperature, helium flow rate, etc., toachieve retention times similar to those in Table 2. Adjust the parametersso that symmetrical, sharp peaks with satisfactory resolution are obtained.Adjust the
48、hydrogen and air flow rates so that the flame response issensitive but constant for concentration changes over the 0 to 0.1 % rangeof diethylene glycol.10.2 Inject 2 L of the sample into the injection port of theinstrument and leave the needle in the port for at least 28 s.NOTE 5The time the needle
49、should be left in the injection port mayvary from instrument to instrument. Leave the needle long enough so thatmaximum sized peaks are obtained for a fixed volume of sample.10.3 Obtain a chromatogram of the sample using attenua-tion settings that allow for maximum peak heights for eachpeak without going off scale. Approximate retention times forthe glycols are given in Table 2. A typical chromatogram isshown in Fig. 1.10.4 Repeat 10.3 to obtain a duplicate chromatogram. Thearea percent of each glycol peak of the chromatograms shouldagree within approximatel
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