ASTM_D_7041_-_16.pdf

Designation:D704116Standard Test Method forDetermination of Total Sulfur in Liquid Hydrocarbons andHydrocarbon-Oxygenate Blends by Gas Chromatographywith Flame Photometric Detection1This standard is issued under the fixed designation D7041;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.Scope*1.1 This test method covers the determination of total sulfurin liquid hydrocarbons with a final boiling point less than450 C by gas chromatography using a flame photometricdetector.1.2 This test method is applicable for total sulfur levels from0.5 mg S/kg to 100 mg S/kg.NOTE1The pooled limit of quantification(PLOQ)derived from the2002 interlaboratory cooperative test program was determined to be1 mgS kg.NOTE2Samples can also be tested at other total sulfur levels,but theprecision statements may not apply.1.3 The values stated in SI units are to be regarded asstandard.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.For specific hazardstatements see Section 7.2.Referenced Documents2.1 ASTM Standards:2D1298 Test Method for Density,Relative Density,or APIGravity of Crude Petroleum and Liquid Petroleum Prod-ucts by Hydrometer MethodD4052 Test Method for Density,Relative Density,and APIGravity of Liquids by Digital Density MeterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsE840 Practice for Using Flame Photometric Detectors in GasChromatography3.Summary of Test Method3.1 The sample is analyzed by gas chromatography with aflame photometric detector.A fixed amount of sample isinjected into the gas chromatograph where it is vaporized.Theair carrier stream carries the vaporized sample into a hightemperature zone(900 C)where the compounds present inthe sample are oxidized.Sulfur compounds are converted tosulfur dioxide(SO2).The carrier stream carries the oxidationcomponents onto a chromatographic column where they areseparated and the SO2is quantified by the flame photometricdetector.Calibration of the detector is achieved by the use of anappropriate external standard.4.Significance and Use4.1 This test method can be used to determine total sulfurlevels in process feeds and finished products that fall within thescope of this test method.4.2 Low levels of sulfur in process feed stocks can poisonexpensive catalysts used in petroleum refining processes.Thistest method can be used to monitor sulfur levels in thesefeedstocks.5.Apparatus5.1 Gas Chromatograph,equipped with automatically con-trolled valves,capable of automatic calibration with an exter-nal standard and having a flame photometric detector with anoverall sensitivity to detect at least 0.5 mg/kg of SO2.It mustbe able to automatically control all valve switching times.Although originally developed with online analytical measure-ment equipment in an offline mode of operation,suitable onlineor laboratory gas chromatographs may apply this test methodas described.Typical instrument parameters are listed in Table1.5.1.1 Carrier and Detector Gas ControlThe chromato-graph must be equipped with flow controllers or pressurecontrollers capable of maintaining a constant supply of carriergas and detector supply gases.Electronic pressure or flowcontrol is highly recommended.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved April 1,2016.Published April 2016.Originallyapproved in 2004.Last previous edition approved in 2010 as D7041 04(2010)1.DOI:10.1520/D7041-16.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.1.2 Sample Injection SystemAn automatic sample injec-tion device is required.The injector must allow the introduc-tion of small sample sizes(0.1 Lto 1 L).The sample must beaccurately and repeatably injected into the gas chromatograph.Rotary or stem type liquid injection valves or auto injectors arerecommended.The valve or injector must be equipped with aheated vaporizer section capable of being heated to at least285 C.5.2 Pyrolysis FurnaceA furnace capable of maintaining asufficient temperature(900