1、Designation:D322808(Reapproved 2014)Standard Test Method forTotal Nitrogen in Lubricating Oils and Fuel Oils by ModifiedKjeldahl Method1This standard is issued under the fixed designation D3228;the number immediately following the designation indicates the year oforiginal adoption or,in the case of
2、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 U.S.Department of Defense.1.Scope1.1 This test method
3、covers the determination of nitrogen inlubricating oils when present in the concentration from 0.03 to0.10 mass%,and for the determination of nitrogen in fuel oilswhen present in the concentration from 0.015 to 2.0 mass%.This test method is also applicable to the analysis of additiveconcentrates and
4、 additive packages.NOTE1This test method may not be applicable to certain materialscontaining NO or NN linkage.However,the samples used in thecooperative program to establish the precision of the test method werecompounded with currently available ashless additives containing nitro-gen.Complete reco
5、very of the nitrogen present in these additives wasobtained.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 therespo
6、nsibility 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 specificwarning statements,see 6.6,6.9,and 8.8.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD4057
7、 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceE200 Practice for Preparation,Standardization,and Storageof Standard and Reagent Solutions for
8、Chemical Analysis3.Summary of Test Method3.1 The sample is digested in a mixture of concentratedsulfuric acid,potassium sulfate,mercuric oxide,and coppersulfate.After digestion,sodium sulfide is added to precipitatethe mercury,and the mixture is made alkaline with caustic.Nitrogen,now in the form of
9、 ammonia,is distilled into a boricacid solution.The ammonia is titrated with standard sulfuricacid using methyl purple as an indicator.4.Significance and Use4.1 The concentration of nitrogen is a measure of thepresence of nitrogen-containing additives.Knowledge of itsconcentration can be used to pre
10、dict performance.5.Apparatus5.1 Buret,50-mL,graduated in 0.1-mLsubdivisions,one foreach titrant.Other size burettes may also be used.5.2 Flask,Erlenmeyer,300-mL.Other sizes are also accept-able.5.3 Heater,electrical or gas.5.4 Kjeldahl Distillation Apparatus.NOTE2Commercially available semiautomatic
11、 Kjeldahl apparatus areacceptable.In such cases manufacturer prescribed sizes of burettes andflasks may be used.5.5 Kjeldahl Flask,at least 500-mL volume.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall
12、 conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,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.Cur
13、rent edition approved May 1,2014.Published July 2014.Originally approvedin 1973.Last previous edition approved in 2008 as D3228 08.DOI:10.1520/D3228-08R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStan
14、dards 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 where such specifications are availa
15、ble.3Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Ty
16、pes II and III of Specification D1193.6.3 Boric Acid Solution(40 g/L)Dissolve 40 g of boricacid(H3BO3)in 1 L of boiling water.6.4 Catalyst Reagent4For each test carefully weigh andmix 9.9 g of potassium sulfate(K2SO4),0.41 g of mercuricoxide(HgO),and 0.08 g of copper sulfate(CuSO4).6.5 Methyl Purple Indicator Solution5Aqueous solutioncontaining approximately 0.1%active constituent(not methylviolet).Other appropriate indicator solutions may also be used.6.6 Sodium Hydroxide Solution(1000 g/L)Diss
