ASTM_D_7423_-_09_2014.pdf

Designation:D742309(Reapproved 2014)Standard Test Method forDetermination of Oxygenates in C2,C3,C4,and C5Hydrocarbon Matrices by Gas Chromatography and FlameIonization Detection1This standard is issued under the fixed designation D7423;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 gas chromatographic pro-cedure for the quantitative determination of organic oxygenatesin C2,C3,C4,and C5 matrices by multidimensional gaschromatography and flame ionization detection.This testmethod is applicable when the hydrocarbon matrices have afinal boiling point not greater than 200C.Oxygenate com-pounds include,but are not limited to,those listed in Table 1.The linear working range for oxygenates is 0.50 mg/kg to 100mg/kg.1.2 This test method is intended to determine the massconcentration of each oxygenate in the hydrocarbon matrix.Oxygenate compound identification is determined by referencestandards and column elution retention order.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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 practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1265 Practice for Sampling Liquefied Petroleum(LP)Gases,Manual MethodD1835 Specification for Liquefied Petroleum(LP)GasesD4175 Terminology Relating to Petroleum,PetroleumProducts,and LubricantsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6849 Practice for Storage and Use of Liquefied PetroleumGases(LPG)in Sample Cylinders for LPG Test MethodsE355 Practice for Gas Chromatography Terms and Relation-ships3.Terminology3.1 Additional terminology related to the practice of gaschromatography can be found in Practice E355.3.2 Definitions:3.2.1 liquefied petroleum gas(LPG),na mixture of nor-mally gaseous hydrocarbons,predominantly propane orbutane,or both,that has been liquefied by compression orcooling,or both,to facilitate storage,transport,and handling.D41753.2.2 oxygenate,nan oxygen-containing ashless organiccompound,such as an alcohol or ether,which may be used asa fuel or fuel supplement.D41753.3 Definitions of Terms Specific to This Standard:3.3.1 Deans switching methodrepresentative aliquot ofsample is injected on-column using a sample valve(or via a gaschromatograph split inlet).The sample passes onto a nonpolarcolumn,which elutes the lighter hydrocarbons in boiling pointorder to the analytical column and backflushes the heavierhydrocarbons to vent.The oxygenate compounds elute fromthe analytical column and are detected via a flame ionizationdetector.3.3.2 Deans switching method direct injectgas chromato-graphic valve configuration equipped with a valve connecteddirectly to the precolumn.This technique is commonly used forthe determination of oxygenates in ethene and propene con-centrates.This configuration provides the lowest detectionlimits such as those commonly required for ethene and propeneconcentrates.3.3.3 Deans switching method equipped with a split inletgas chromatographic valve configuration equipped with a gaschromatograph split inlet for sample introduction into theprecolumn.This configuration is commonly used for the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.D0.04 on C4 Hydrocarbons.Current edition approved May 1,2014.Published July 2014.Originally approvedin 2009.Last pervious edition approved in 2009 as D7423 09.DOI:10.1520/D7423-09R14.2For 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 determination of oxygenates in C5 hydrocarbon mixtures.Thistechnique using this configuration might not provide thedetection limits noted in the scope of this test method.If lowerdetection limits are required,then the user should considerusing the on-column valve direct injection technique.3.3.4 valve cut methodcommonly used for the determina-tion of oxygenates in C4 hydrocarbon mixtures.This techniqueusing a split inlet might not provide the detection limits notedin the scope of this test method.If lower detection limits arerequired,then the user should consider using t