ASTM_D_7756_-_13.pdf

Designation:D775613Standard Test Method forResidues in Liquefied Petroleum(LP)Gases by GasChromatography with Liquid,On-Column Injection1This standard is issued under the fixed designation D7756;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,by gaschromatography,of soluble hydrocarbon materials,sometimescalled“oily residue,”which can be present in LiquefiedPetroleum(LP)Gases and which are substantially less volatilethan the LPG product.1.2 This test method quantifies,in the range of 10 to 600mg/kg(ppm mass),the residue with a boiling point between174C and 522C(C10to C40)in LPG.Higher boilingmaterials,or materials that adhere permanently to the chro-matographic column,will not be detected.1.3 Appendix X3 and Appendix X4 describe additionalapplications which could be performed based on the hardwareand procedures described in this test method.Appendix X3describes a test procedure for expanding the analysis range tobenzene,and Appendix X4 describes a test procedure for theanalysis of diisopropanolamine in LPG.1.4 UnitsThe values stated in SI units are to be regardedas standard.The values given in parentheses are for informa-tion only.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:2D1265 Practice for Sampling Liquefied Petroleum(LP)Gases,Manual MethodD1835 Specification for Liquefied Petroleum(LP)GasesD2158 Test Method for Residues in Liquefied Petroleum(LP)GasesD2163 Test Method for Determination of Hydrocarbons inLiquefied Petroleum(LP)Gases and Propane/PropeneMixtures by Gas ChromatographyD2421 Practice for Interconversion of Analysis of C5andLighter Hydrocarbons to Gas-Volume,Liquid-Volume,orMass BasisD2598 Practice for Calculation of Certain Physical Proper-ties of Liquefied Petroleum(LP)Gases from Composi-tional AnalysisD3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6667 Test Method for Determination of Total VolatileSulfur in Gaseous Hydrocarbons and Liquefied PetroleumGases by Ultraviolet FluorescenceE355 Practice for Gas Chromatography Terms and Relation-shipsE594 Practice for Testing Flame Ionization Detectors Usedin Gas or Supercritical Fluid Chromatography3.Terminology3.1 Definitions of Terms Concerning ChromatographyThis test method makes reference to many common gaschromatographic procedures,terms,and relationships.Detaileddefinitions of these can be found in Practices E355 and E594.3.2 Definitions of Terms Concerning Liquefied PetroleumGasesThis test method makes reference to the definitions ofliquefied petroleum gases as described in Specification D1835.3.3 Definitions of Terms Specific to This Standard:3.3.1 high pressure liquefied gas injector,nSample intro-duction device which injects liquefied gas samples underpressure and at room temperature directly onto the chromato-graphic column thereby maintaining the sample in liquid phaseduring the injection process.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.H0 on Liquefied Petroleum Gas.Current edition approved June 15,2013.Published July 2013.Originallyapproved in 2011.Last previous edition approved in 2012 as D775612.DOI:10.1520/D7756-13.2For 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 3.3.2 pressure station,nDevice that supplies high pres-sure nitrogen to a suitable sample cylinder and thereforemaintains sample in the liquid phase during the injectionprocedure.4.Summary of Test Method4.1 A sample cylinder of LPG is pressurized to 2500 kPa(363 psi)using nitrogen or helium.4.2 The injection system is flushed with LPG in liquid phaseat room temperature.4.3 After flushing,the injection device is routed to the GCinjector port and LPG(25 milliseconds activation time equiva-lent to 30 L)is introduced via a high pressure valve andnee