1、Designation: D7716 11Standard Test Method forDetermination of Residual Methanol in Glycerin by GasChromatography1This standard is issued under the fixed designation D7716; 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. Scope1.1 This test method provides for the quantitative determi-nation of residual methanol in glycerin by gas chromatography.
3、The range of detection for residual methanol is 0.02 to 0.60mass %.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It
4、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. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD7640 Specification for Engine Coolant Grade
5、 GlycerinE355 Practice for Gas Chromatography Terms and Rela-tionshipsE594 Practice for Testing Flame Ionization Detectors Usedin Gas or Supercritical Fluid Chromatography3. Terminology3.1 DefinitionsThis test method makes reference to manycommon gas chromatographic procedures, terms, and relation-s
6、hips. Detailed definitions can be found in Practices E355 andE594.4. Summary of Test Method4.1 The sample is analyzed by headspace gas chromatogra-phy. Calibration is achieved by the use of external standards ofmethanol in water.5. Significance and Use5.1 Methanol content reflects the quality of gly
7、cerin for useas an engine coolant. The current specification for the maxi-mum methanol content is 0.1 % weight to weight (w/w).6. Apparatus6.1 Chromatographic SystemSee Practice E355 for spe-cific designations and definitions. The gas chromatograph (GC)system shall be capable of operating at the con
8、ditions given inTable 1.6.2 Autosampler system, Gerstel multipurpose samplerMPS-23or equivalent. This method can also be run manually.6.3 Column, open tubular column with polyethylene glycol(PEG) bonded and cross-linked phase internal coating. Thecolumn should have an upper temperature limit of 260C
9、. Acolumn 30 m in length, with an internal diameter of 0.32 mm,and a 1.0-m film thickness has been found satisfactory. Anycolumn with equivalent or better chromatographic efficiencyand selectivity can be used.6.4 Electronic Data Acquisition SystemA computer ca-pable of providing real-time graphic an
10、d digital presentation ofthe chromatographic data is recommended for use. Peak areasand retention times shall be measured by computer or elec-tronic integration (integrator).7. Reagents and Materials7.1 Purity of ReagentsReagent-grade chemicals shall beused in all tests. Unless otherwise indicated,
11、it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society where1This test method is under the jurisdiction of ASTM Committee D15 on EngineCoolants and is the direct responsibility of Subcommittee D15.93 on Research andLong R
12、ange Planning.Current edition approved June 1, 2011. Published August 2011. DOI: 10.1520/D7716-11.2For 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 Docu
13、ment Summary page onthe ASTM website.3The sole source of supply of the apparatus known to the committee at this timeis GERSTEL GmbH glycerin; headspace; methanolASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this sta
14、ndard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be revi
15、ewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsib
16、le technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
17、nshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D7716 114
