ASTM D6591-2011 red 8125 Standard Test Method for Determination of Aromatic Hydrocarbon Types in Middle DistillatesHigh Performance Liquid Chromatography Method with Refractive Ind.pdf

1、Designation:D659106 Designation: D6591 11Designation: 548/06Standard Test Method forDetermination of Aromatic Hydrocarbon Types in MiddleDistillatesHigh Performance Liquid ChromatographyMethod with Refractive Index Detection1This standard is issued under the fixed designation D6591; the number immed

2、iately 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.INTRODUCTIONThis

3、test method has the same title as IP 548-06 and is intended to be technically equivalent. TheASTM format for test methods has been used, and where possible, equivalent ASTM test methodshave replaced the IP or ISO standards.The test method is intended to be used as one of several possible alternative

4、 instrumental testmethods that are aimed at quantitative determination of hydrocarbon types in fuels. This does notimply that a correlation necessarily exists between this and any other test method intended to give thisinformation, and it is the responsibility of the user to determine such correlati

5、on if necessary.1. Scope*1.1 This test method covers a high performance liquid chromatographic test method for the determination of mono-aromatic,di-aromatic, tri+-aromatic, and polycyclic aromatic hydrocarbon contents in diesel fuels and petroleum distillates boiling in therange from 150 to 400C. T

6、he total aromatic content in % m/m is calculated from the sum of the corresponding individual aromatichydrocarbon types.NOTE 1Aviation fuels and petroleum distillates with a boiling point range from 50 to 300C are not determined by this test method and should beanalyzed by Test Method, D6379 or othe

7、r suitable equivalent test methods.1.2 The precision of this test method has been established for diesel fuels and their blending components, containing from 4to 40 % (m/m) mono-aromatic hydrocarbons, 0 to 20 % (m/m) di-aromatic hydrocarbons, 0 to 6 % (m/m) tri+-aromatichydrocarbons, 0 to 26 % (m/m)

8、 polycyclic aromatic hydrocarbons, and 4 to 65 % (m/m) total aromatic hydrocarbons.1.3 Compounds containing sulfur, nitrogen, and oxygen are possible interferents. Mono-alkenes do not interfere, but conjugateddi- and poly-alkenes, if present, are possible interferents.1.4 By convention, this standar

9、d defines the aromatic hydrocarbon types on the basis of their elution characteristics from thespecified liquid chromatography column relative to model aromatic compounds. Quantification is by external calibration using asingle aromatic compound, which may or may not be representative of the aromati

10、cs in the sample, for each aromatic hydrocarbontype. Alternative techniques and methods may classify and quantify individual aromatic hydrocarbon types differently.1.5 Fatty Acid Methyl Esters (FAME), if present, interfere with tri+-aromatic hydrocarbons. If this method is used for dieselcontaining

11、FAME, the amount of tri+-aromatics will be over estimated.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicabili

12、ty of regulatorylimitations prior to use.1This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.04.0Con Liquid Chromatography.This test method is based on material published in IP Standard Methods fo

13、r Analysis and Testing of Petroleum and Related Products and British Standard 2000 Parts,copyright The Institute of Petroleum, 61 New Cavendish Street, London W1M 8AR. Adapted with permission of The Institute of Petroleum.Current edition approved Nov.Dec. 1, 2006.2011. Published December 2006.Februa

14、ry 2012. Originally approved in 2000. Last previous edition approved in 20002006 asD659100.D659106. DOI: 10.1520/D6591-06.10.1520/D6591-11.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous

15、version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes

16、section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2. Referenced Documents2.1 ASTM Standards:2D1319 Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator Adsor

17、ptionD2425 Test Method for Hydrocarbon Types in Middle Distillates by Mass SpectrometryD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD5186 Test Method for Determination of theAromatic Content and Polynuc

18、learAromatic Content of Diesel Fuels andAviationTurbine Fuels By Supercritical Fluid ChromatographyD6379 Test Method for Determination of Aromatic Hydrocarbon Types in Aviation Fuels and Petroleum DistillatesHighPerformance Liquid Chromatography Method with Refractive Index Detection2.2 IP Standard:

19、 Energy Institute Standard:3IP 548 Test Method for Determination of Aromatic Hydrocarbon Types in Middle Distillates High Performance LiquidChromatography Method with Refractive Index Detection3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 di-aromatic hydrocarbons (DAHs), nin

20、 this test method, compounds that have a longer retention time on the specifiedpolar column than the majority of mono-aromatic hydrocarbons, but a shorter retention time than the majority of tri+-aromatichydrocarbons.3.1.2 mono-aromatic hydrocarbons (MAHs), nin this test method, compounds that have

21、a longer retention time on thespecified polar column than the majority of non-aromatic hydrocarbons but a shorter retention time than the majority of DAHs.3.1.3 non-aromatic hydrocarbons, nin this test method, compounds that have a shorter retention time on the specified polarcolumn than the majorit

22、y of mono-aromatic hydrocarbons.3.1.4 polycyclic aromatic hydrocarbons (POLY-AHs), nin this test method, sum of the di-aromatic hydrocarbons andtri+-aromatic hydrocarbons.3.1.5 total aromatic hydrocarbons, nin this test method, sum of the MAHs, DAHs, and T+AHs.3.1.6 tri+-aromatic hydrobons (T+AHs),

23、nin this test method, compounds that have a longer retention time on the specifiedpolar column than the majority of DAHs.3.1.6.1 DiscussionThe elution characteristics of aromatic and non-aromatic compounds on the specified polar column havenot been specifically determined for this test method. Publi

24、shed and unpublished data indicate the major constituents for eachhydrocarbon type as follows: (1) non-aromatic hydrocarbons: acyclic and cyclic alkanes (paraffins and naphthenes), mono-alkenes(if present), (2) MAHs: benzenes, tetralins, indanes, thiophenes, and conjugated poly-alkenes, (3) DAHs: na

25、phthalenes, biphenyls,indenes, fluorenes, acenaphthenes, and benzothiophenes and dibenzothiophenes, (4) T+AHs: phenanthrenes, pyrenes, fluo-ranthenes, chrysenes, triphenylenes, and benzanthracenes.4. Summary of Test Method4.1 A known mass of sample is diluted in the mobile phase, and a fixed volume

26、of this solution is injected into a highperformance liquid chromatograph, fitted with a polar column. This column has little affinity for the non-aromatic hydrocarbonswhile exhibiting a pronounced selectivity for aromatic hydrocarbons. As a result of this selectivity, the aromatic hydrocarbons arese

27、parated from the non-aromatic hydrocarbons into distinct bands in accordance with their ring structure, that is, MAHs, DAHs,and T+AHs.At a predetermined time, after the elution of the DAHs, the column is backflushed to elute the T+AHs as a single sharpband.4.2 The column is connected to a refractive

28、 index detector that detects the components as they elute from the column. Theelectronic signal from the detector is continually monitored by a data processor. The amplitudes of the signals (peak areas) fromthe sample aromatics are compared with those obtained from previously measured calibration st

29、andards in order to calculatepercent m/m MAHs, DAHs, and T+AHs in the sample. The sum of the percentages by mass of DAHs and T+AHs is reported asthe percent m/m POLY-AH. The sum of MAHs, DAHs, and T+AHs is reported as the total aromatic content (percent m/m) of thesample.5. Significance and Use5.1 T

30、he aromatic hydrocarbon content of motor diesel fuel is a factor that can affect exhaust emissions and fuel combustioncharacteristics, as measured by cetane number.5.2 The United States Environmental Protection Agency (US EPA) regulates the aromatic content of diesel fuels. California AirResources B

31、oard (CARB) regulations place limits on the total aromatics content and polynuclear aromatic hydrocarbon content2For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the st

32、andards Document Summary page on the ASTM website.3Available from Institute of Petroleum, 61 New Cavendish St., London, WIM 8AR, UK.3Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR, U.K., http:/www.energyinst.org.D6591 112of motor diesel fuel, thus requiring an appropriate ana

33、lytical determination to ensure compliance with the regulations.5.3 This test method is applicable to materials in the same boiling range as motor diesel fuels and is unaffected by fuelcoloration. Test Method D1319, which has been mandated by the US EPA for the determination of aromatics in motor di

34、esel fuel,excludes materials with final boiling points greater than 315C (600F) from its scope. Test Method D2425 is applicable to thedetermination of both total aromatics and polynuclear aromatic hydrocarbons in diesel fuel, but is much more costly andtime-consuming to perform. Test Method D5186, c

35、urrently specified by CARB, is also applicable to the determination of both totalaromatics and polynuclear aromatic hydrocarbons in diesel fuel. Test Method D5186, however, specifies the use of supercriticalfluid chromatography equipment that may not be readily available.NOTE 2Test Method D5186 was

36、previously specified by CARB as an alternative to Test Method D1319.6. Apparatus6.1 High Performance Liquid Chromatograph (HPLC)Any HPLC capable of pumping the mobile phase at flow rates between0.5 and 1.5 mL/min, with a precision better than 0.5 % and a pulsation of 1%. better than 1 %.6.2.1 An equ

37、al and constant volume of the calibration and sample solutions shall be injected into the chromatograph. Bothmanual and automatic sample injection systems (using either complete or partial filling of the sample loop) will, when usedcorrectly, meet the repeatability requirements laid down in 6.2. Whe

38、n using the partial loop-filling mode, it is recommended thatthe injection volume should be less than half the total loop volume. For complete filling of the loop, best results are obtained byoverfilling the loop at least six times.NOTE 3The repeatability of the injection system may be checked by co

39、mparing peak areas from at least four injections of the system performancestandard (see 9.3).6.2.2 Sample and calibration injection volumes other than 10 L (typically in the range from 3 to 20 L) may be used, providedthey meet the requirements laid down for injection repeatability (see 6.2), refract

40、ive index sensitivity and linearity (see 9.4.2 and10.1.5), and column resolution (see 9.4.3).6.3 Sample Filter, if required (see 10.2.1)A microfilter of porosity 0.45 m or less, which is chemically-inert towardshydrocarbon solvents, is recommended for the removal of particulate matter from the sampl

41、e solutions.6.4 Column SystemAny stainless steel HPLC column(s) packed with an approved amino-bonded (or polar amino/cyano-bonded) silica stationary phase is suitable, provided it meets the resolution requirements laid down in 9.4.3. See Appendix X1 forguidance on the selection and use of suitable c

42、olumn systems.6.5 HPLC Column OvenAny suitable HPLC column oven (block heating or air circulating) capable of maintaining a constanttemperature (6 1C) within the range from 20 to 40C.NOTE 4The refractive index detector is sensitive to both sudden and gradual changes in the temperature of the eluent.

43、 All necessary precautionsshould be taken to establish constant temperature conditions throughout the liquid chromatograph system. The temperature should be optimized dependingon the stationary phase.NOTE 5Alternative forms of temperature control, for example, temperature-controlled laboratories, ar

44、e permitted.6.6 Backflush ValveAny manual or automatic (air or electrically actuated) flow-switching valve designed for use in HPLCsystems that is capable of operating at pressures up to 2 3 104kPa.6.7 Refractive Index DetectorAny refractive index detector may be used provided it is capable of being

45、 operated over therefractive index range from 1.3 to 1.6, meets the sensitivity requirement specified in 9.4.2, gives a linear response over thecalibration range, and has a suitable output signal for the data system.NOTE 6If the refractive index detector has a facility for independent temperature co

46、ntrol, it is recommended that this be set at the same temperatureas the column oven.6.8 Computer or Computing IntegratorAny data system can be used provided it is compatible with the refractive indexdetector, has a minimum sampling rate of 1 Hz, and is capable of peak area and retention time measure

47、ment. The data systemshould also have minimum facilities for post-analysis data processing, such as baseline correction and reintegration. The abilityto perform automatic peak detection and identification and to calculate sample concentrations from peak area measurements isrecommended but not essent

48、ial.6.9 Volumetric Flasks, Grade B or better, of 10 and 100 mL capacity.6.10 Analytical Balance, accurate to 60.0001 g.7. Reagents7.1 Cyclohexane, 99 % pure.NOTE 7Cyclohexane may contain benzene as an impurity.7.2 Heptane, HPLC Grade. For use as HPLC mobile phase. (WarningHeptane is highly flammable

49、 and may cause irritationby inhalation, ingestion, or skin contact.)D6591 113NOTE 8Batch to batch variation of the solvent quality in terms of water content, viscosity, refractive index and purity could cause unpredictablecolumn behavior. Drying and filtering the mobile phase could help to reduce the effect of the trace impurities in the solvent.NOTE 9It is recommended practice to degas the HPLC mobile phase before use; this can be done conveniently, on-line, or off-line by helium sparging,vacuum degassing or ultrasonic agitation. A failure to