1、Designation:D838321Standard Test Method forMethyl Hydrogen Content of Hydrocarbon Oils by HighResolution Nuclear Magnetic Resonance Spectroscopy1This standard is issued under the fixed designation D8383;the number immediately following the designation indicates the year oforiginal adoption or,in the
2、 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.Scope1.1 This test method covers the determination of the totalmethyl hydrogen content of unadditized
3、base stock(lubricatingoils)hydrocarbon oils that are completely soluble in chloro-form at ambient temperature using high-resolution nuclearmagnetic resonance(NMR)spectrometers.1.2 The reported units are mol percent methyl hydrogenatoms.For pulse Fourier transform(FT)spectrometers,thedetection limit
4、is typically 0.1%mol hydrogen atoms.Theinterim precision is applicable in the range 20.5%to 38.7%mol methyl hydrogen.1.3 This method is applicable to samples containing 0.1%mol olefinic hydrogens.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are includ
5、ed in thisstandard.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,health,and environmental practices and deter-mine the applicability of regulatory limitation
6、s prior to use.Specific precautionary statements are given in 7.2 and 7.3.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Rec
7、om-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD5292 Test Method for Aromatic Carbon Contents of Hy-drocarbon Oils by High ResolutionNuclear M
8、agneticResonance Spectroscopy(Withdrawn 2018)3D6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300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,Liquid
9、Fuels,and LubricantsE386 Practice for Data Presentation Relating to High-Resolution Nuclear Magnetic Resonance(NMR)Spec-troscopy(Withdrawn 2015)33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 methyl hydrogen,nH-NMR signal in the spectralregion of 0.1 ppm to the valley at appro
10、ximately 1 ppm as apercentage of total hydrogens.3.1.1.1 DiscussionNMR spectrometers meeting vendorspecifications for signal to noise ratio and resolution areacceptable as defined in 6.1.3.2 Definitions of chemical shift(reported in parts permillion(ppm),internal reference,spectral width,and otherNM
11、R terminology used in this test method can be found inPractice E386 or any suitable vendor recommended method toconvert to ppm.3.3 Chloroform-d refers to chloroform solvent in whichhydrogen is replaced by deuterium,the heavier isotope ofhydrogen.Chloroform-d is available from a variety of chemi-cal
12、and isotope suppliers(Test Method D5292).4.Summary of Test Method4.1 Hydrogen(1H)nuclear magnetic resonance(NMR)spectraareobtainedonsolutionsofthesampleinchloroform-d,using a pulse FT high-resolution NMR spec-trometer.Tetramethylsilane is preferred as an internal referencein these solvents for assig
13、ning the 0.0 parts per million(ppm)chemical shift position in the1H spectra.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0F on Absorption Spectroscopic Methods.Current edition
14、 approved April 1,2021.Published April 2021.DOI:10.1520/D8383-21.2For 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.3
15、The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standar
16、dization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.4.2 The methyl hydrogen content of the sample is measuredby comparing the total integral for the1H NMR spectrum ofthe 0.1 ppm to about 1 ppm chemical shift region with theintegral from 0.1 ppm to about 8 ppm.Integration is for all thesignal peaks greater than 0.1%,excluding the solvent peaks.4.