1、Designation: D 3545 06Standard Test Method forAlcohol Content and Purity of Acetate Esters by GasChromatography1This standard is issued under the fixed designation D 3545; 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 (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method covers the determ
3、ination by gaschromatography of the ester content and the correspondingalcohol content of acetate esters. This test method has beenapplied to ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and2-ethoxyethyl acetates.1.2 Water, and in some cases acetic acid, cannot be deter-mined by this test method a
4、nd must be measured by otherappropriate ASTM procedures and the results used to normal-ize the chromatographic value.1.3 For purposes of determining conformance of an ob-served or a calculated value using this test method to relevantspecifications, test result(s) shall be rounded off “to the nearest
5、unit” in the last right-hand digit used in expressing thespecification limit, in accordance with the rounding-off methodof Practice E 29.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 For specific hazard information and
6、 guidance, see thesuppliers Material Safety Data Sheet for material listed in thisspecification.1.6 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 p
7、ractices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1364 Test Method for Water in Volatile Solvents (KarlFischer Reagent Titration Method)D 1613 Test Method for Acidity in Volatile Solvents andChemical Intermediates Used in Pa
8、int, Varnish, Lacquer,and Related ProductsD 2593 Test Method for Butadiene Purity and HydrocarbonImpurities by Gas ChromatographyE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 180 Practice for Determining the Precision of ASTMMethods for Analysis
9、and Testing of Industrial and Spe-cialty ChemicalsE 260 Practice for Packed Column Gas Chromatography3. Summary of Test Method3.1 A representative specimen is introduced into a gas-liquid partition column. The acetate is separated from impuri-ties such as alcohols, other esters, ethers, and several
10、uniden-tified compounds while the components are transportedthrough the column by an inert carrier gas. The separatedcomponents are measured in the effluent by a detector andrecorded as a chromatogram. The chromatogram is interpretedby applying component attenuation and detector responsefactors to t
11、he peak areas, and the relative concentrations aredetermined by relating the individual peak responses to thetotal peak response. Water and acidity are measured by TestMethods D 1364 and D 1613, respectively, and the results areused to normalize the values obtained by gas chromatography.4. Significa
12、nce and Use4.1 This test method is useful for identifying and fordetermining the quantity of various impurities in acetate esters.4.2 Total purity of the acetate esters must be determined byuse of other appropriate ASTM procedures with this testmethod.5. Apparatus5.1 ChromatographAny gas chromatogra
13、ph having eithera thermal conductivity or flame ionization detector, providedthe system has sufficient sensitivity and stability to obtain for1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility o
14、fSubcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates.Current edition approved June 1, 2006. Published June 2006. Originallyapproved in 1976. Last previous edition approved in 2002 as D 3545 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
15、Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards 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 Conshoho
16、cken, PA 19428-2959, United States.0.01 % of the parent alcohol a recorder deflection of at least 20mm at a signal-to-noise ratio of at least 5 to 1. The specimensize used in judging the sensitivity must be such that thecolumn is not overloaded, which would result in peak broad-ening, loss of resolu
17、tion, shifting retention times and formationof leading peaks. Volumes of 5 L with thermal conductivityand 1 to 2 L with flame ionization detectors have been foundacceptable.5.1.1 The injection port of the chromatograph must have avolume of at least 1.2 mL to provide for proper vaporization ofthe mat
18、erial. The use of a smaller injection port or on-columninjection has been found to cause peak broadening and tailing.5.2 ColumnA 3-m length of 6.4-mm outside diameteraluminum or stainless steel tubing packed with 80 to 100-meshChromosorb G-HP3,4,5that has been coated with 9.05 % DowCorning QF-15,6si
19、licone and 0.45 % nonylphenoxypoly(ethyl-eneoxy)ethanol(CAS # 9016459), HLB = 19.0 has beenfound suitable.7Any column, packed or capillary, or anypacking material capable of resolving one acetate ester fromany other esters and from any impurities that may be presentand giving equivalent or superior
20、performance may be used.5.3 RecorderA recording potentiometer with a full-scaledeflection of 1 mV. Full-scale response time should be2sorless with sufficient sensitivity and stability to meet the require-ments of 5.1.5.4 Specimen Introduction SystemAny system capable ofintroducing a representative s
21、pecimen into the column. Mi-crolitre syringes have been used successfully.6. Reagents and Materials6.1 Carrier Gas, appropriate to the type of detector used.Helium or hydrogen may be employed with thermal conduc-tivity detectors and nitrogen, helium, or argon with flameionization detectors. The mini
22、mum purity of the carrier gasused should be 99.95 mol %.6.1.1 If hydrogen is used special safety precautions must betaken to ensure that the system is free of leaks and that theeffluent is vented properly.6.2 Column Materials:6.2.1 Liquid Phase, Dow Corning QF-1/FS 12655,6siliconeand nonylphenoxypol
23、y(ethyleneoxy)ethanol(CAS #9016459), HLB = 19.76.2.2 Solid Support, Chromosorb G-HP,3,5,480 to 100 meshsize.6.2.3 SolventsMethylene chloride and acetone, reagentgrade.6.2.4 Tubing MaterialStainless steel and aluminum havebeen found satisfactory for column tubing. The tubing must benonreactive with t
24、he substrate, sample, and carrier gas andmust be of uniform internal diameter.6.3 Standards for Calibration and IdentificationStandardsamples of all components present are needed for identificationby retention time and for calibration for quantitative measure-ments. Most can be obtained from chemica
25、l supply houses.7. Preparation of Apparatus7.1 Column Packing PreparationPlace 100 g of Chro-mosorb G-HP,3,5,480 to 100 mesh, in a large evaporating dish.Dissolve 10 g of Dow Corning QF-1/FS 12655,6silicone in 50mL of acetone and add to the solid support. Add sufficientacetone to wet and cover the s
26、olid support. Evaporate theacetone in a fume hood with gentle stirring and under a gentlestream of nitrogen. Dissolve 0.5 g of nonylphenoxypoly(eth-ylenexy)ethanol(CAS # 9016459). HLB = 19.07in 50 mL ofmethylene chloride and add it to the packing material. Addsufficient methylene chloride to wet and
27、 cover the packing.Evaporate the methylene chloride with gentle stirring under agentle stream of nitrogen. Commercially available columns orpackings, or both, are available from several chromatographysupply sources.7.2 Column PreparationThe method used to pack thecolumn is not critical provided that
28、 the finished columnproduces the required separation of all of the components to bedetermined. Commercially available columns or packings, orboth, are available from several chromatography supplysources.7.3 ChromatographInstall the column in the chromato-graph. Use the information in Table 1 as a gu
29、ide to establish theconditions of column temperature and carrier gas flow that givethe necessary resolution of the components in the productbeing analyzed. Allow sufficient time for the instrument toreach equilibrium as indicated by a stable recorder baseline.Control the detector temperature constan
30、t to within 1C with-out thermostat cycling, which causes an uneven baseline.Adjust the carrier-gas flow rate to a constant value.NOTE 1Useful information on column preparation may be found inTest Method D 2593 and Practice E 260.8. Calibration and Standardization8.1 IdentificationDetermine the reten
31、tion time of eachcomponent by injecting small amounts either separately or inknown mixtures. The esters should elute close to the typicalretention times given in Table 1 and the chromatograms shouldclosely approximate those shown in Figs. 1-6.8.2 The area under each peak of the chromatogram isconsid
32、ered a quantitative measure of the corresponding com-pound. The relative area is proportional to concentration if thedetector responds equally to all the sample components. Theresponse to different components is generally significantlydifferent for both flame ionization and thermal conductivitydetec
33、tors and especially for flame ionization detectors. Differ-ence in detector response may be corrected by use of relativeresponse factors obtained by injecting and measuring theresponse to known blends. For precise and accurate determi-nation of the parent alcohol, prepare and analyze a knownblend of
34、 the acetate and alcohol in which the alcohol contentapproximates the maximum specification limit. Calculate the3A registered trademark of Manville Products Corp., Lompoc, CA 93436.4The sole source of supply for this material known to the committee at this timeis Manville Products Corp., Lompoc, CA
35、93436.5If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee1which you may attend.6The sole source of supply for Silicoup QF-1/FS 1265 (1000)
36、known to thecommittee at this time is Dow-Corning Corp., Midland, MI 48640.7Aregistered trademark of GAF Corp., Dyestuff and Chemical Div., 140 W. 51stSt., New York, NY 10020.D3545062alcohol response factor relative to unity for the acetate. Withthermal conductivity detectors, the response factor of
37、 allimpurities other than the alcohol may be assumed to be one forobtaining the purity value. With flame ionization detectors, useexperimentally determined response factors.NOTE 2Data on thermal conductivity and flame ionization detectorresponses may be found in the literature.89. Procedure9.1 Intro
38、duce a representative specimen into the chromato-graph using sufficient material to ensure a minimum of 10 %recorder deflection for a 0.1 % concentration of impurity at themost sensitive setting of the instrument.9.2 Using the same conditions as for component identifica-tion and standardization, rec
39、ord the peaks of all components atattenuation settings that provide optimum peak heights. Mea-sure the area of all peaks (Note 3) and multiplying each area bythe appropriate attenuation factor to express the peak areas ona common basis.NOTE 3Peak areas may be determined by any method that meets thep
40、recision in Section 12. Electronic integration of peak areas was employedto obtain the results used to establish the precision of this test method.10. Calculation10.1 Apply the appropriate detector response factor tocorrect for the difference in response to the components. Makecorrection to account
41、for water and acidity as determined bythe ASTM procedures given in Test Methods D 1364, D 1613,D 2593, and Practices E 180 and E 260.10.2 Calculate the weight percent of each component asfollows:Weight % 5 A/B! 3 100 2 C! (1)where:A = corrected peak response of a component,B = sum of corrected peak
42、responses, andC = sum of water and acidity (as acetic acid), weight %.10.3 Calculate the percent composition by dividing theindividual corrected component areas by the total correctedarea.11. Report11.1 Report the percent purity of the acetate being analyzedand the corresponding alcohol to the neare
43、st 0.01 % absolute.Duplicate runs for ester content that agree within 0.06 %absolute are acceptable for averaging (95 % confidence level).Duplicate runs for the parent alcohol content that agree within0.02 % absolute are acceptable for averaging.12. Precision and Bias912.1 The precision statements a
44、re based upon an interlabo-ratory study in which one operator in each of nine laboratoriesanalyzed in duplicate on two days one sample of each of thefollowing esters:MeanMean AlcoholEster Purity ContentEthyl acetate 99.8 0.17n-Propyl acetate 96.9 2.7Isopropyl acetate 99.2 0.46n-Butyl acetate 98.5 0.
45、48Isobutyl acetate 98.7 0.452-Ethoxyethyl acetate 99.1 0.51The results were analyzed in accordance with PracticeE 180. Within-laboratory and between-laboratory standard de-viations were found to be as follows:Ester ContentWithinLaboratoriesBetweenLaboratoriesEthyl acetate 0.019 (8)A0.026 (7)An-Propy
46、l acetate 0.032 (8) 0.138 (7)Isopropyl acetate 0.014 (7) 0.071 (6)n-Butyl acetate 0.029 (6) 0.056 (5)Isobutyl acetate 0.042 (8) 0.213 (7)2-Ethoxyethyl acetate 0.014 (8) 0.142 (7)_ADegrees of freedom are shown in parentheses.Parent Alcohol ContentWithinLaboratoriesBetweenLaboratoriesEthyl acetate 0.0
47、04 (7)A0.028 (6)An-Propyl acetate 0.015 (8) 0.062 (7)Isopropyl acetate 0.003 (8) 0.009 (7)Parent Alcohol ContentWithinLaboratoriesBetweenLaboratoriesn-Butyl acetate 0.004 (7) 0.011 (6)Isobutyl acetate 0.014 (8) 0.017 (7)2-Ethoxyethyl acetate 0.005 (8) 0.015 (7)_ADegrees of freedom are shown in paren
48、theses.Based upon these standard deviations, the following criteriashould be used for judging the acceptability of results at the95 % confidence level.12.1.1 RepeatabilityTwo results, each the mean of dupli-cates, obtained by the same operator on different days shouldbe considered suspect if they di
49、ffer by more than the following:Ester contentAlcoholContent(% absolute)Ethyl acetate 0.06 0.01n-Propyl acetate 0.10 0.05Isopropyl acetate 0.05 0.01n-Butyl acetate 0.10 0.01Isobutyl acetate 0.14 0.052-Ethoxyethyl acetate 0.04 0.028Messner, A. E., et al, Analytical Chemistry, Vol 31, 1959, pp. 230233. Dietz,W. A., Journal of Gas Chromatography, Vol 5, No. 2, February 1967, pp. 6871.9Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D01-1004.D3545063TABLE 1 Instrume
