ASTM_D_7059_-_09_2013.pdf

Designation:D705909(Reapproved 2013)Standard Test Method forDetermination of Methanol in Crude Oils byMultidimensional Gas Chromatography1This standard is issued under the fixed designation D7059;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 methanolin crude oils by direct injection multidimensional gas chroma-tography in the concentration range of 15 to 900 ppm(m/m).The pooled limit of quantification(PLOQ)is 15 ppm(m/m).1.2 This test method is applicable only to crude oils con-taining less than or equal to 0.1%(v/v)water.1.3 This test method has not been tested with crude oilsamples that are solid or waxy,or both,at ambient tempera-tures.1.4 The values stated in SI units are to be regarded asstandard.Alternate units,in common usage,are also providedto increase clarity and aid the users of this test method.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 practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D4006 Test Method for Water in Crude Oil by DistillationD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD4928 Test Method for Water in Crude Oils by CoulometricKarl Fischer TitrationD6596 Practice for Ampulization and Storage of Gasolineand Related Hydrocarbon Materials3.Terminology3.1 Definitions:3.1.1 analytical column,nporous layer open tubular(PLOT)column with a stationary phase selective for oxygen-ates.It is used to resolve methanol from 1-propanol to provideaccurate quantitative results.3.1.2 cool-on-column injector,nan injection port thatallows controlled injection of the sample at a temperature closeto or lower than the boiling point of the solvent into the gaschromatographic column or a liner within the injection portconnected to the column.3.1.2.1 DiscussionAfter the injection,the injection port isheated at a fixed rate to a temperature sufficiently high enoughto allow the transfer of sample components of interest from theinjection port to the part of the column located in the gaschromatograph(GC)oven.3.1.3 electronic pressure control,nelectronic pneumaticcontrol of carrier gas flows.It can be flow or pressureprogrammed to speed up elution of components.3.1.4 low-volume connector,na special union for connect-ing two lengths of tubing 1.6-mm inside diameter and smaller;sometimes referred to as a zero dead-volume union.3.1.5 pre-column,na polydimethylsiloxane WCOT col-umn used to isolate the methanol and 1-propanol and severallight hydrocarbons from the higher boiling portion of the crudeoil sample for transfer to the analytical column for furtherseparation and quantification.3.1.6 programmable temperature vaporizer(PTV),natemperature programmable injector similar to a cool-on-column injector except that the sample is injected cool into aglass liner or insert instead of the WCOT(3.1.5)column andthen the temperature is programmed in a manner similar to theon-column injector.3.1.6.1 DiscussionThelinermaybereplaced,asnecessary,to remove non-volatile materials.This injector maybe operated in low split mode or direct(no splitting)mode.3.1.7 split/splitless injector,na heated capillary inlet orsample introduction system that allows controlled splitting ofthe injected sample into two unequal portions,the smaller ofwhich goes to the capillary column,and the greater to a vent.3.1.7.1 DiscussionWhen the vent is closed,the entire1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricantsand is the direct responsibility ofSubcommittee D02.04.0L on Gas Chromatography Methods.Current edition approved Oct.1,2013.Published October 2013.Originallyapproved in 2004.Last previous edition approved in 2009 as D7059 09.DOI:10.1520/D7059-09R13.2For 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 sample enters the capillary column and the inlet is operated asa splitless injector.When the vent is open,the inlet is operatedin the split mode and only a portion of the sample reaches thecapillary column.The ratio of the split between the capillarycolumn and the vent is calculated as described in 3.1.7.1.3.1.7.1 split ratio,nin capillary gas chromatography,theratio of the tot