1、Designation: E 611 08Standard 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 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.NOTE 2Test Method E 2409 desc
5、ribes another gas chromatographictest method for the determination of glycol impurities in mono-, di-, tri-and tetraethylene glycol (MEG, DEG, TEG and TeEG) in the range of 5to 3000 g/g.1.2 The two test methods are given as follows:SectionsTest Method ANonderivative Method 5 to 13Test Method BDeriva
6、tive Method 14 to 221.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard with the exception of foot-pound units for apparatusdescriptions.1.4 Review the current Material Safety Data Sheets (MSDS)for detailed information concernin
7、g toxicity, first aid proce-dures, and safety precautions for chemicals used in thisstandard.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 prac
8、tices 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 of Industri
9、al and Spe-cialty ChemicalsE 202 Test Methods for Analysis of Ethylene Glycols andPropylene GlycolsE 2409 Test Method for Glycol Impurities in Mono-, Di-,Tri- and Tetraethylene Glycol (Gas ChromatographicMethod)2.2 Other Documents: Manufacturers instruction manu-als of gas chromatograph3. Significan
10、ce 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 technique, based on the assumption that all componentsare eluted under the conditions used. If all components shou
11、ldnot 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,the results are on a water-free basis. Water may be determinedin accordance with the applicable sections of Tes
12、t MethodsE 202 and the gas chromatographic results corrected for thewater concentration.3.2 Both test methods are currently in industrial use. TestMethodAis the simpler of the two test methods because it doesnot require the preparation of derivatives prior to gas chro-matographic analysis. The resul
13、ts obtained by Test Method A1These 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 Dec. 15, 2008. Published January 2009. Originallyapproved in 1
14、977. Discontinued September 1996 and reinstated as E 611 03. Lastprevious edition approved in 2003 as E 61103.2For 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 st
15、andards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.are slightly more accurate than those obtained by Test MethodB. With r
16、espect to precision there is no significant differencebetween the two test methods. Test Method 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
17、in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the 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 i
18、s of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.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.
19、1 The sample is injected into a gas chromatographiccolumn. The components are separated as they pass throughthe column with helium carrier gas, their presence in theeffluent is detected by a flame ionization detector, and recordedas a chromatogram. The areas under the peaks due to thesample componen
20、ts 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 1).6.1.1 Sample Injection Port, with heater characteristicsnecessary f
21、or 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 sensitivity will be reduced andwater may be detected as a peak eluting w
22、ith 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-tion with a chart speed of approximately 1.3 cm/min or otherconvenient
23、 speed that will produce a satisfactory chromato-gram, and an attenuator switch to change the recorder range asrequired to keep the chromatogram on scale.NOTE 3On instruments using electronic integration the attenuationfeature is not required.6.1.5 Column, 50 in. long,316 in. in outside diameter wit
24、h awall thickness of 0.030 in. for copper or 0.020 in. for stainlesssteel construction; packed with 10 % polyethylene glycol onorange calcinated diatomite with dimethyldichlorosilane,DMCS, 60/80 mesh.6.1.6 Microsyringe, 10-L capacity.6.1.7 Copper or Stainless Steel Tubing,316 in. in outsidediameter
25、with a wall thickness of 0.030 in. for copper or 0.020in. for stainless steel.NOTE 4The copper tubing should be sealed, refrigeration grade. If theseal has been broken, clean the copper tubing with an acetone wash anddry with nitrogen before filling. Stainless steel tubing should be pre-washed with
26、successive volumes of 10 % HCl, distilled water, acetone,methylene chloride, and dried with nitrogen.7. Reagents and Materials7.1 Air, compressed.7.2 Orange Calcinated Diatomite with Dimethyldichlorosi-lane, 60/80 mesh.7.3 Ethylene Glycol and Diethylene GlycolSee Section 9for purity requirements.7.4
27、 Helium (He).7.5 Hydrogen (H2).7.6 Methylene Chloride (Dichloromethane) (CH2Cl2).7.7 Polyethylene Glycol, 20 000 molecular weight.8. Preparation of Chromatographic Column8.1 Dissolve 20 g of the polyethylene glycol in approxi-mately 200 mL of CH2Cl2with gentle warming to aid solution.3Reagent Chemic
28、als, 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 NationalFormula
29、ry , U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.TABLE 1 Instrument Parameters, 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
30、) outside diameter copper orstainless steel tubing packed with 10 % polyethylene glycol.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 t
31、emperature 168CSample size 2 LInjection time 28 sAThe parameters in this table apply to 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.E611082Add 180 g
32、 of orange calcinated diatamite with dimethyldichlo-rosilane, DMCS, and sufficient CH2Cl2to form a slurry, andmix well, making certain that all particles 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
33、 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 the 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 127-cm
34、section1.4-cm outside diameter copper or stainless steel tubing withthe screened packing retained on the 80-mesh screen. Gentlyvibrate the tubing during packing to ensure uniform packing.Use borosilicate glass wool for plugs in the ends of the column.Columns packed using vacuum or by blowing the pac
35、king intothe tubing are generally unsatisfactory.8.3 Condition the column prior to use by placing the columnin the chromatograph in 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 ord
36、er to obtain the composition of the sample in termsof mass percent, multiply the areas associated with the com-ponents by an appropriate calibration factor. These factors areobtained from mixtures of known composition, and should bedetermined for each apparatus. The calibration factors may beobtaine
37、d using standards prepared from “hearts cuts” from thedistillation of each of the glycols, or from commercial gradesof each glycol as described in the following test methods. Forhighest accuracy, use glycols obtained from “hearts cuts.”Check the calibration factors periodically or whenever there ise
38、vidence of a change in the column or instrument.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 30 % and retaining the next 30 % as the “hearts cuts.”Analyze these fractions as described in Sec
39、tion 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 standard should be known to thenearest 0.001 %. Correct the composition for any water presentusin
40、g 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 and calculate the averagearea percent for each of the glycols present in accordance with11.2.1.
41、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 diethylene glycol asdescribed in 11.1.1.Assume a calibration factor of unity for theethylene gl
42、ycol 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 described in Section 10 indicates that the concen-tration of the ethylene glycol in the diethylene gl
43、ycol 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 test method. The base ethylene glycol should contain lessthan 0.05 area % diethylene glycol.9.3.2
44、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 composition for any waterpresent using the equation in 11.2.4. Determine the watercontent as described
45、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 %, the concentrationof the impurity is insignificant at the concentration levelsincluded in the scope
46、 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 with10.2 and calculate the average area percent for each of theglycols present in accordance wit
47、h 11.2.1. Do not include anyareas associated with the pressure peak in calculating the areapercentages. Using the mass percent of diethylene glycol addedto the ethylene glycol and the average area percentages for theglycols calculate the calibration factor for the diethylene glycolin accordance with
48、 11.1.2. Assume the calibration factor ofunity for the ethylene glycol in the base ethylene glycol and thestandard mixture.10. Procedure10.1 Mount the column in the chromatograph, and adjustthe operating conditions in accordance with the parametersgiven in Table 1 (see Note 5). Allow sufficient time
49、 for theinstrument to reach equilibrium as indicated by a stable baseline on the chart at the maximum sensitivity setting to be used.NOTE 5The instrument parameters given in Table 1 were developedfor the 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 hydrogen and air flow rates so that the flame response issensi
