1、Designation: D2549 02 (Reapproved 2017)Standard Test Method forSeparation of Representative Aromatics and NonaromaticsFractions of High-Boiling Oils by Elution Chromatography1This standard is issued under the fixed designation D2549; the number immediately following the designation indicates the yea
2、r 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.1. Scope1.1 This test method covers the separation and determina-ti
3、on of representative aromatics and nonaromatics fractionsfrom hydrocarbon mixtures that boil between 232 C and538 C (450 F and 1000 F). Alternative procedures are pro-vided for the separation of 2 g or 10 g of hydrocarbon mixture.NOTE 1Some components may not be eluted from the chromato-graphic colu
4、mn for some types of samples under the conditions used inthis method.NOTE 2Test Method D2007 is an alternative method of separatinghigh-boiling oils into polar compounds, aromatics, and saturates fractions.1.2 An alternative procedure is provided to handle samplesboiling below 232 C (450 F), but who
5、se 5 % point is above178 C (350 F) as determined by Test Method D2887. Thisprocedure is given in Appendix X1.1.3 The values stated in acceptable SI units are to beregarded as the standard. The values given in parentheses areprovided for information purposes only.1.4 This standard does not purport to
6、 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 limitations prior to use.1.5 This international standard was
7、developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced
8、 Documents2.1 ASTM Standards:2D2007 Test Method for Characteristic Groups in RubberExtender and Processing Oils and Other Petroleum-Derived Oils by the Clay-Gel Absorption Chromato-graphic MethodD2425 Test Method for Hydrocarbon Types in Middle Dis-tillates by Mass SpectrometryD2786 Test Method for
9、Hydrocarbon Types Analysis ofGas-Oil Saturates Fractions by High Ionizing VoltageMass SpectrometryD2887 Test Method for Boiling Range Distribution of Pe-troleum Fractions by Gas ChromatographyD3239 Test Method for Aromatic Types Analysis of Gas-OilAromatic Fractions by High Ionizing Voltage Mass Spe
10、c-trometry3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 aromatics fractionthe portion of the sample des-orbed with the polar eluants. The aromatics fraction maycontain aromatics, condensed naphthenic-aromatics, aromaticolefins, and compounds containing sulfur, nitrogen, and
11、oxy-gen atoms.3.1.2 nonaromatics fractionthe portion of the sampleeluted with n-pentane. The nonaromatics fraction is a mixtureof paraffinic and naphthenic hydrocarbons if the sample is astraight-run material. If the sample is a cracked stock, thenonaromatics fraction will also contain aliphatic and
12、 cyclicolefins.4. Summary of Test Method4.1 A weighed amount of sample is charged to the top of aglass chromatographic column packed with activated bauxiteand silica gel. n-Pentane is added to the column to elute thenonaromatics. When all of the nonaromatics are eluted, thearomatics fraction is elut
13、ed by additions of diethyl ether,chloroform, and ethyl alcohol.4.2 The solvents are completely removed by evaporation,and the residues are weighed and calculated as the aromaticsand nonaromatics fractions of the sample.5. Significance and Use5.1 The determination of compound types by mass spec-trome
14、try requires, in some instances, a preliminary separation1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.04.0C on Liquid Chromatography.Current edition approved Dec. 1, 2017. Publ
15、ished December 2017. Originallyapproved in 1966. Last previous edition approved in 2012 as D2549 02 (2012).DOI: 10.1520/D2549-02R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inform
16、ation, refer to the standards Document Summary page onthe ASTM website.This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendat
17、ions issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1of the petroleum sample into representative aromatics andnonaromatics fractions, as in Test Methods D2425, D2786, andD3239. This test method provides a suitable separation tech-nique for this application.6. Appa
18、ratus6.1 Chromatographic Columns, as shown in Fig. 1. Differ-ent chromatographic columns are provided for the analysis of2 g and 10 g samples.6.2 Beakers, 100 mL, 250 mL, and 600 mL, inverted-rimtype.36.3 Steam Bath.6.4 Electric Vibrator, for packing column.6.5 Weighing Bottles or Erlenmeyer Flasks,
19、 25 mL and50 mL.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in this test. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such speci
20、fications are available.4Other 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.3The sole source of supply of the beakers known to the committee at this timeis Kontes Glass Co., Vin
21、eland, NJ; order “Anti-Creep” beakers and refer to DrawingNo. 9413-A. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee1, whichyou may atten
22、d.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmaco
23、peiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Chromatographic ColumnsD2549 02 (2017)27.2 Bauxite,520 mesh to 60 mesh. Before use, activate thebauxite by heating at 538 C (1000 F) for 16 h. Transfer theactivated material to an airtight container while sti
24、ll hot andprotect thereafter from atmospheric moisture.7.3 Chloroform. (WarningToxic. May be fatal if swal-lowed.)7.4 Cleaning SolutionChromic-sulfuric acid. (WarningCauses severe burns.Arecognized carcinogen, strong oxidizer,contact with organic material may cause fire.)7.5 Diethyl Ether, anhydrous
25、. (WarningExtremely flam-mable.) The ethyl ether used in this test method should be freeof peroxides as determined by the procedure in “ReagentChemical, American Chemical Society Specifications.”7.6 Ethyl Alcohol, denatured, conforming to Formula 2B ofthe U.S. Bureau of Internal Revenue. (WarningFla
26、mmable.)7.7 Pressuring Gas, dry air or nitrogen, delivered to the topof the column at a regulated gage pressure of 0 psi to 2 psi(13.8 kPa). (WarningCompressed gas.)7.8 n-Pentane, commercial grade, aromatic-free. Somesamples of waxy stocks may not dissolve completely inn-pentane, in which case cyclo
27、hexane, commercial grade,aromatic-free, may be substituted for n-pentane. (WarningExtremely flammable liquid.)7.9 Silica Gel,6100 mesh to 200 mesh.8. ProcedureNOTE 3The procedural details differ depending on the initial boilingpoint of the sample. If the 5 % point is above 178 C (350 F), but below23
28、2 C (450 F), use procedure described in Appendix X1. If above232 C, continue as written depending on amount of sample to beanalyzed. Instructions specific for 2 g samples are given in 8.4.1 8.4.13,and instructions specific for 10 g samples are given in 8.5.1 and 8.5.8.8.1 Select the appropriate colu
29、mn, depending on whether2 g or 10 g of sample are to be analyzed. Clean the columnwith chromic-sulfuric acid (WarningCauses severe burns),followed by distilled or demineralized water, acetone, and dryair or nitrogen.8.2 Introduce a small plug of glass wool into the column,pressing it firmly into the
30、 lower end to prevent the flow of silicagel from the column.8.3 Clamp the column in a vertical position. Add smallincrements of silica gel, while vibrating the column along itslength, until the tightly packed silica gel extends to the lowermark on the chromatographic column. Continue to vibrate thec
31、olumn and add bauxite until the bauxite layer extends to theupper mark on the chromatographic column. Vibrate thecolumn for an additional 3 min after filling is completed.8.4 If 2 g of sample are to be analyzed, continue as in 8.4.1,otherwise continue as in 8.5.8.4.1 If the sample is viscous, warm i
32、t with intermittentmixing or shaking until it is completely fluid. Transfer arepresentative sample (approximately 2 g) to a 25 mL weigh-ing bottle or flask. Determine the mass of the sample to thenearest 1 mg by weighing the flask before and after sampletransfer. Add 10 mL of n-pentane (WarningExtre
33、mely flam-mable liquid), to the flask and dissolve the sample. If thesample does not dissolve completely in cold n-pentane, warmit in warm water or over a steam bath. If the sample does notdissolve in warm n-pentane, take a fresh sample and substitutecyclohexane for the n-pentane.8.4.2 Add 10 mL of
34、n-pentane to the top of the column toprewet the adsorbent. When the liquid level reaches the top ofthe bauxite bed, transfer the sample solution from the weighingflask to the top of the column. Rinse the flask with threesuccessive 3 mL washes of n-pentane. Add each wash to thetop of the column. Then
35、 rinse the walls of the column bulb withtwo 3 mL portions of n-pentane, allowing the liquid level toreach the top of the bauxite bed before adding the next portion.Finally add 35 mL of n-pentane to the column bulb.8.4.3 Place a 50 mL graduate beneath the column to collectthe eluate. The elution rate
36、 should be approximately 1 mL min.NOTE 4Gas pressure (WarningCompressed gas) can be applied tothe top of the column as necessary to maintain the elution rate atapproximately 1 mL min. If the correct pressure setting is known fromprevious runs, gas pressure may be applied after addition of the lastin
37、crement of n-pentane. Otherwise, gas pressure should be applied whenn-pentane begins to elute from the column and should be adjusted to givea flow rate of approximately 1 mL min.8.4.4 When the n-pentane level reaches the top of thebauxite bed, add 80 mL of diethyl ether (WarningExtremelyflammable).
38、Connect the pressuring gas to the top of thecolumn and adjust the pressure to maintain an elution rate of1 mL min to 2 mL min.8.4.5 Collect 50 mL of n-pentane eluate in the graduate.Rinse the tip of the column with 1 mL to 2 mL of n-pentane,adding this to the 50 mL in the graduate (Note 5). Label th
39、e50 mL graduate as n-pentane eluate.NOTE 5The n-pentane will have reached the adsorbent bed before therequired volume of eluate has been collected in the 50 mL receiver.Continue collection in this receiver after the addition of ether until theproper volume has been collected before changing to the 1
40、00 mLgraduate.8.4.6 When the ether level reaches the top of the bauxitebed, release the gas pressure and add 100 mL of chloroform(WarningToxic. May be fatal if swallowed) to the top of thecolumn. Reconnect the gas pressuring system and continue theelution. When 80 mL of eluate have been collected in
41、 thegraduate, rinse the column tip with 1 mL of ether and add therinse to the 100 mL graduate. Change the receiver to a 250 mLgraduate. Label the 100 mL graduate as ether-eluted fraction.8.4.7 When the chloroform level reaches the top of thebauxite bed, release the gas pressure and add 75 mL of ethy
42、lalcohol (WarningFlammable liquid). Reconnect the gaspressuring system and continue the elution until the alcohollevel reaches the top of the bauxite bed. Release the gaspressure. Rinse the column tip with 1 mL of chloroform adding5The sole source of supply of the bauxite known to the committee at t
43、his timeis Porocel Corp., Little Rock, AR. If you are aware of alternative suppliers, pleaseprovide this information to ASTM International Headquarters. Your comments willreceive careful consideration at a meeting of the responsible technical committee1,which you may attend.6The sole source of suppl
44、y of the silica gel known to the committee at this timeis W.R. Grace and Co., Davison Chemical Div., Baltimore, MD 21203, byspecifying Code 923. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful considerati
45、on at a meeting of the responsible technical committee1, whichyou may attend.D2549 02 (2017)3this to the graduate. Label the 250 mL graduate as chloroform-alcohol-eluted fraction.8.4.8 Weigh a 100 mL inverted-rim beaker to the nearest1 mg. Quantitatively transfer the n-pentane eluate to thisbeaker a
46、nd allow the n-pentane to evaporate at room tempera-ture. Cyclohexane, if used as the elution solvent, is evaporatedon a steam bath. Evaporation is accelerated in both cases bydirecting a controlled stream of dry nitrogen downward ontothe surface of the liquid.8.4.9 When all the solvent appears to b
47、e evaporated, stopthe nitrogen flow, allow the beaker to come to roomtemperature, and dry the outside of the beaker to remove anycondensed moisture. Reweigh the beaker to the nearest 1 mg.NOTE 6Complete solvent evaporation is indicated by a tendency ofthe oil to creep up the side of the beaker.8.4.1
48、0 Repeat the evaporation step for 5 min periods untilthe mass loss between successive evaporations is less than20 mg. Heat from a steam bath is generally required during thefinal evaporation steps to remove completely the elutionsolvent. The mass of the residue in the beaker is the quantity ofthe no
49、naromatics fraction.8.4.11 Weigh a 250 mL inverted-rim beaker to the nearest1 mg. Quantitatively transfer the chloroform-alcohol-elutedfraction to this beaker and evaporate on a steam bath with acontrolled stream of dry nitrogen directed downward onto thesurface of the liquid. When the solvent is evaporated, removethe beaker from the steam bath, cool to room temperature, andadd quantitatively the ether-eluted fraction. Evaporate the etherat room temperature as described in 8.4.8 8.4.10. Determinethe mass of the residue (aromatics fractio
