ASTM_D_5441_-_98_2013.pdf

Designation:D544198(Reapproved 2013)Standard Test Method forAnalysis of Methyl Tert-Butyl Ether(MTBE)by GasChromatography1This standard is issued under the fixed designation D5441;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,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.Scope1.1 This test method covers the determination of the purityof methyl tert-butyl ether(MTBE)by gas chromatography.Italso provides a procedure to measure impurities in MTBE suchas C4to C12olefins,methyl,isopropyl and tert-butyl alcohols,methyl sec-butyl and methyl tert-amyl ethers,acetone,andmethyl ethyl ketone.Impurities are determined to a minimumconcentration of 0.02 mass%.1.2 This test method is not applicable to the determinationof MTBE in gasoline.1.3 Water cannot be determined by this test method andmust be measured by a procedure such as Test Method D1364and the result used to normalize the chromatographic values.1.4 Amajority of the impurities in MTBE is resolved by thetest method,however,some co-elution is encountered.1.5 This test method is inappropriate for impurities that boilat temperatures higher than 180C or for impurities that causepoor or no response in a flame ionization detector,such aswater.1.6 The values stated in SI(metric)units of measurementare preferred and used throughout the standard.Alternate units,in common usage,are also provided to improve clarity and aidthe user of this test method.1.7 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 consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1364 Test Method for Water in Volatile Solvents(KarlFischer Reagent Titration Method)D3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD4626 Practice for Calculation of Gas ChromatographicResponse FactorsE355 Practice for Gas Chromatography Terms and Relation-shipsE594 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-ships.Detailed definitions of these can be found in PracticesE355 and E594.3.2 Definitions of Terms Specific to This Standard:3.2.1 C4to C12olefinscommon olefin impurities in MTBEare unreacted feedstock and dimers or trimers of feed such astrimethylpentene or pentamethylheptene.4.Summary of Test Method4.1 A representative aliquot of the MTBE product sample isintroduced into a gas chromatograph equipped with a methylsilicone bonded phase fused silica open tubular column.Helium carrier gas transports the vaporized aliquot through thecolumn where the components are separated by the chromato-graphic process.Components are sensed by a flame ionizationdetector as they elute from the column.4.2 The detector signal is processed by an electronic dataacquisition system or integrating computer.Each eluting com-ponent is identified by comparing its retention time to thoseestablished by analyzing standards under identical conditions.4.3 The concentration of each component in mass percent isdetermined by normalization of the peak areas after each peakarea has been corrected by a detector response multiplication1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0L on Gas Chromatography Methods.Current edition approved May 1,2013.Published August 2013.Originallyapproved in 1993.Last previous edition approved in 2008 as D544198(2008)1.DOI:10.1520/D5441-98R13.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 factor.The detector response factors are determined by ana-lyzing prepared standards with concentrations similar to thoseencountered in the sample.5.Significance and Use5.1 The presence of impurities in MTBE product can have adeleterious effect upon the value of MTBE as a gasolineadditive.Oxygenate and olefin contents are of primary con-cern.This test method provides a knowledge of the composi-tion of MTBE product.This is useful in the evaluation ofprocess operations control,in the valuation of the product,andfor regulatory purposes.5.2 Open tubular column gas