ASTM_D_4629_-_12.pdf

Designation:D462912Designation:379/88Standard Test Method forTrace Nitrogen in Liquid Petroleum Hydrocarbons bySyringe/Inlet Oxidative Combustion and ChemiluminescenceDetection1This standard is issued under the fixed designation D4629;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.This standard has been approved for use by agencies of the Department of Defense.1.Scope*1.1 This test method covers the determination of the tracetotal nitrogen naturally found in liquid hydrocarbons boiling inthe range from approximately 50 to 400C,with viscositiesbetween approximately 0.2 and 10 cSt(mm2/s)at roomtemperature.This test method is applicable to naphthas,distillates,and oils containing 0.3 to 100 mg/kg total nitrogen.For liquid hydrocarbons containing more than 100 mg/kg totalnitrogen,Test Method D5762 can be more appropriate.Thistest method has been successfully applied,during interlabora-tory studies,to sample types outside the range of the scope bydilution of the sample in an appropriate solvent to bring thetotal nitrogen concentration and viscosity to within the rangecovered by the test method.However,it is the responsibility ofthe analyst to verify the solubility of the sample in the solventand that direct introduction of the diluted sample by syringeinto the furnace does not cause low results due to pyrolysis ofthe sample or solvent in the syringe needle.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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.See 6.2,6.4,6.5,6.9,and Section 7.2.Referenced Documents2.1 ASTM Standards:2D1298 Test Method for Density,Relative Density(SpecificGravity),or API Gravity of Crude Petroleum and LiquidPetroleum Products by Hydrometer MethodD4052 Test Method for Density,Relative Density,and APIGravity of Liquids by Digital Density MeterD5762 Test Method for Nitrogen in Petroleum and Petro-leum Products by Boat-Inlet ChemiluminescenceD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance3.Summary of Test Method3.1 The sample of liquid petroleum hydrocarbon is intro-duced either by syringe or boat inlet system,into a stream ofinert gas(helium or argon).The sample is vaporized andcarried to a high temperature zone where oxygen is introducedand organically bound nitrogen is converted to nitric oxide(NO).The NO contacts ozone,and is converted to excitednitrogen dioxide(NO2).The light emitted as the excited NO2decays is detected by a photomultiplier tube and the resultingsignal is a measure of the nitrogen contained in the sample.4.Significance and Use4.1 Some process catalysts used in petroleum and chemicalrefining may be poisoned when even trace amounts of nitrog-enous materials are contained in the feedstocks.This test1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved April 15,2012.Published May 2012.Originallyapproved in 1986.Last previous edition approved in 2010 as D462910.DOI:10.1520/D4629-12.2For 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 method can be used to determine bound nitrogen in processfeeds and may also be used to control nitrogen compounds infinished products.5.Apparatus5.1 Furnace,electric,held at a temperature sufficient tovolatilize and pyrolyze all of the sample and oxidize theorganically bound nitrogen to NO.Furnace temperature(s)shall be as recommended by the manufacturer(typicallyaround 1000C).5.2 Combustion Tube,fabricated to meet the instrumentmanufacturers specifications.5.3 Drier TubeThe reaction products include water vaporthat must be eliminated prior to measurement by the detector.This can be accomplished with a magnesium perchlorateMg(ClO4)2scrubber or a membrane drying tube(permeationdrier),or by whatever other means the instrument manufacturerspecifies as appropriate for the instrument being used.5.4 Chemiluminescent Detector,capable of measuring lightemitted from the reaction between NO and ozone.5.5 Totalizer,having va