1、Designation:D 6366 99Standard Test Method forTotal Trace Nitrogen and Its Derivatives in Liquid AromaticHydrocarbons by Oxidative Combustion andElectrochemical Detection1This standard is issued under the fixed designation D 6366;the number immediately following the designation indicates the year ofo
2、riginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the totaltrace nitrog
3、en(organic and inorganic)naturally found in liquidaromatic hydrocarbons,its derivatives and related chemicals.1.2 This test method is applicable for samples containingnitrogen from 0.05 to 100 mgN/kg.For higher concentrationsrefer to Test Method D 4629.1.3 The detector response for the technique wit
4、hin the scopeof this test method is linear with nitrogen concentration.1.4 The following applies to all specified limits in this testmethod:for purposes of determining conformance with thistest method,an observed value or a calculated value shall berounded off“to the nearest unit”in the last right-h
5、and digitused in expressing the specification limit,in accordance withthe rounding-off method of Practice E 29.1.5 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
6、and health practices and determine the applica-bility of regulatory limitations prior to use.For specific hazardstatements,see Section 9 and Note 2,Note 3,Note 4,and Note8.2.Referenced Documents2.1 ASTM Standards:D 3437 Practice for Sampling and Handling Liquid CyclicProducts2D 3852 Practice for Sam
7、pling and Handling Phenol andCresylic Acid2D 4629 Test Method for Trace Nitrogen in Liquid Petro-leum Hydrocarbons by Syringe/Inlet Oxidative Combus-tion and Chemiluminescence Detection3E 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications42.2Other Docum
8、ent:OSHA Regulations,29 CFR,paragraphs 1910.1000 and1910.120053.Terminology3.1 Definitions:3.1.1 oxidative combustion,na process in which a sampleundergoes combustion in an oxygen-rich environment at tem-peratures greater than 650C and compounds decompose toform carbon dioxide,water and elemental ox
9、ides.4.Summary of Test Method4.1 A sample of liquid aromatic hydrocarbon is injected,ata controlled rate,into a stream of inert gas(helium or argon)orinert gas mixed with oxygen.The sample is vaporized andcarried to a high temperature zone(900C),where oxygen isintroduced.Organic and inorganic nitrog
10、en compounds,present in the specimen,are converted to nitric oxide(NO).Nitric oxide is reacted with the sensing electrode in a3-electrode electrochemical cell.This reaction produces ameasurable current that is directly proportional to the amountof nitrogen in the original sample material.4.1.1 The r
11、eaction that occurs is as follows:Combustion:R2N 1 O2.900C CO21 H2O 1 NO 1 oxides(1)Detection:NO 1 2 H2O electrolyte HNO31 3H1!1 3e!5.Significance and Use5.1 Some process catalysts used in petroleum and chemicalrefining may be poisoned when even trace amounts of nitrog-enous materials are contained
12、in the feedstocks.This testmethod can be used to determine total nitrogen in process feedsand may also be used to control nitrogen compounds infinished products that fall within the scope of this test method.NOTE1Virtually all organic and inorganic nitrogen compounds willdetected by this technique.5
13、.2 This technique will not detect diatomic nitrogen and itwill produce an attenuated response when analyzing com-pounds(that is,5-triazine and azo compounds,etc.)that form1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Materials,and is the direct
14、 responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved Jan.10,1999.Published March 1999.2Annual Book of ASTM Standards,Vol 06.04.3Annual Book of ASTM Standards,Vol 05.02.4Annual Book of ASTM Standards,Vol 14.02.5Available from Superintendent of Documents,U.S.Governme
15、nt PrintingOffice,Washington,DC 20402.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.nitrogen gas(N2)when decomposed.6.Interferences6.1 Moisture produced during the combustion step caninterfere if not removed prior to the detector.7.Appa
16、ratus7.1 Pyrolsis Furnace,capable of maintaining a temperaturesufficient to volatilize and combust all of the sample andoxidize the organically bound nitrogen to NO.The furnacetemperatures for petroleum substances shall be as recom-mended by the manufacturer.7.2 Quartz Combustion Tube,capable of withstanding 900to 1200C.The inlet end of the tube holds a septum for syringeentry of the sample and has inlet fittings or side arms for theintroduction of oxygen(O2)and inert gas.The construction issuch
