ASTM D2549-02(2012)
(Test Method)Standard Test Method for Separation of Representative Aromatics and Nonaromatics Fractions of High-Boiling Oils by Elution Chromatography
Standard Test Method for Separation of Representative Aromatics and Nonaromatics Fractions of High-Boiling Oils by Elution Chromatography
SIGNIFICANCE AND USE
The determination of compound types by mass spectrometry requires, in some instances, a preliminary separation of the petroleum sample into representative aromatics and nonaromatics fractions, as in Test Methods D2425, D2786, and D3239. This test method provides a suitable separation technique for this application.
SCOPE
1.1 This test method covers the separation and determination of representative aromatics and nonaromatics fractions from hydrocarbon mixtures that boil between 232 and 538°C (450 and 1000°F). Alternative procedures are provided for the separation of 2 g or 10 g of hydrocarbon mixture.
Note 1—Some components may not be eluted from the chromatographic column for some types of samples under the conditions used in this method.
Note 2—Test Method D2007 is an alternative method of separating high-boiling oils into polar compounds, aromatics, and saturates fractions.
1.2 An alternative procedure is provided to handle samples boiling below 232°C (450°F), but whose 5 % point is above 178°C (350°F) as determined by Test Method D2887. This procedure is given in Appendix X1.
1.3 The values stated in acceptable SI units are to be regarded as the standard. The values given in parentheses are provided for information purposes only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and heal practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D2549 − 02 (Reapproved 2012)
Standard Test Method for
Separation of Representative Aromatics and Nonaromatics
Fractions of High-Boiling Oils by Elution Chromatography
This standard is issued under the fixed designation D2549; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D2786 Test Method for Hydrocarbon Types Analysis of
Gas-Oil Saturates Fractions by High Ionizing Voltage
1.1 This test method covers the separation and determina-
Mass Spectrometry
tion of representative aromatics and nonaromatics fractions
D2887 Test Method for Boiling Range Distribution of Pe-
from hydrocarbon mixtures that boil between 232 and 538°C
troleum Fractions by Gas Chromatography
(450 and 1000°F). Alternative procedures are provided for the
D3239 Test Method forAromatic TypesAnalysis of Gas-Oil
separation of2gor10gof hydrocarbon mixture.
Aromatic Fractions by High Ionizing Voltage Mass Spec-
NOTE 1—Some components may not be eluted from the chromato-
trometry
graphic column for some types of samples under the conditions used in
this method.
3. Terminology
NOTE 2—Test Method D2007 is an alternative method of separating
high-boiling oils into polar compounds, aromatics, and saturates fractions.
3.1 Definitions of Terms Specific to This Standard:
1.2 An alternative procedure is provided to handle samples
3.1.1 aromatics fraction—the portion of the sample des-
boiling below 232°C (450°F), but whose 5 % point is above orbed with the polar eluants. The aromatics fraction may
178°C (350°F) as determined by Test Method D2887. This
contain aromatics, condensed naphthenic-aromatics, aromatic
procedure is given in Appendix X1. olefins, and compounds containing sulfur, nitrogen, and oxy-
gen atoms.
1.3 The values stated in acceptable SI units are to be
regarded as the standard. The values given in parentheses are 3.1.2 nonaromatics fraction—the portion of the sample
provided for information purposes only. eluted with n-pentane. The nonaromatics fraction is a mixture
of paraffinic and naphthenic hydrocarbons if the sample is a
1.4 This standard does not purport to address all of the
straight-run material. If the sample is a cracked stock, the
safety concerns, if any, associated with its use. It is the
nonaromatics fraction will also contain aliphatic and cyclic
responsibility of the user of this standard to establish appro-
olefins.
priatesafetyandhealpracticesanddeterminetheapplicability
of regulatory limitations prior to use.
4. Summary of Test Method
2. Referenced Documents
4.1 A weighed amount of sample is charged to the top of a
2.1 ASTM Standards: glass chromatographic column packed with activated bauxite
D2007 Test Method for Characteristic Groups in Rubber and silica gel. n-Pentane is added to the column to elute the
Extender and Processing Oils and Other Petroleum- nonaromatics. When all of the nonaromatics are eluted, the
Derived Oils by the Clay-Gel Absorption Chromato- aromatics fraction is eluted by additions of diethyl ether,
graphic Method chloroform, and ethyl alcohol.
D2425 Test Method for Hydrocarbon Types in Middle Dis-
4.2 The solvents are completely removed by evaporation,
tillates by Mass Spectrometry
and the residues are weighed and calculated as the aromatics
and nonaromatics fractions of the sample.
This test method is under the jurisdiction of ASTM Committee D02 on
5. Significance and Use
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.04.0C on Liquid Chromatography.
5.1 The determination of compound types by mass spec-
Current edition approved April 15, 2012. Published April 2012. Originally
trometry requires, in some instances, a preliminary separation
approved in 1966. Last previous edition approved in 2007 as D2549–02(2007).
DOI: 10.1520/D2549-02R12.
of the petroleum sample into representative aromatics and
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
nonaromaticsfractions,asinTestMethodsD2425,D2786,and
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
D3239. This test method provides a suitable separation tech-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. nique for this application.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2549 − 02 (2012)
FIG. 1 Chromatographic Columns
6. Apparatus where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of
6.1 Chromatographic Columns, as shown in Fig. 1. Differ-
sufficiently high purity to permit its use without lessening the
ent chromatographic columns are provided for the analysis of
accuracy of the determination.
2 and 10-g samples.
7.2 Bauxite, 20to60-mesh.Beforeuse,activatethebauxite
6.2 Beakers, 100, 250, and 600-mL, inverted-rim type.
by heating at 538°C (1000°F) for 16 h. Transfer the activated
6.3 Steam Bath.
material to an airtight container while still hot and protect
6.4 Electric Vibrator, for packing column.
thereafter from atmospheric moisture.
6.5 Weighing Bottles or Erlenmeyer Flasks, 25 and 50 mL.
7.3 Chloroform. (Warning—Toxic. May be fatal if swal-
lowed.)
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be
used in this test. Unless otherwise indicated, it is intended that
Reagent Chemicals, American Chemical Society Specifications, American
all reagents shall conform to the specifications of the Commit-
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
tee onAnalytical Reagents of theAmerican Chemical Society,
listed by the American Chemical Society, see Annual Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
The sole source of supply of the beakers known to the committee at this time MD.
isKontesGlassCo.,Vineland,NJ;order“Anti-Creep”beakersandrefertoDrawing The sole source of supply of the bauxite known to the committee at this time
No. 9413-A. If you are aware of alternative suppliers, please provide this is Porocel Corp., Little Rock, AR. If you are aware of alternative suppliers, please
information to ASTM International Headquarters. Your comments will receive provide this information toASTM International Headquarters. Your comments will
1 1
careful consideration at a meeting of the responsible technical committee , which receive careful consideration at a meeting of the responsible technical committee ,
you may attend. which you may attend.
D2549 − 02 (2012)
7.4 Cleaning Solution—Chromic-sulfuric acid.(Warning— sample does not dissolve completely in cold n-pentane, warm
Causes severe burns.Arecognized carcinogen, strong oxidizer, it in warm water or over a steam bath. If the sample does not
contact with organic material may cause fire.) dissolve in warm n-pentane, take a fresh sample and substitute
cyclohexane for the n-pentane.
7.5 Diethyl Ether, anhydrous. (Warning—Extremely flam-
8.4.2 Add 10 mL of n-pentane to the top of the column to
mable.) The ethyl ether used in this test method should be free
prewet the adsorbent. When the liquid level reaches the top of
of peroxides as determined by the procedure in “Reagent
thebauxitebed,transferthesamplesolutionfromtheweighing
Chemical, American Chemical Society Specifications.”
flask to the top of the column. Rinse the flask with three
7.6 Ethyl Alcohol, denatured, conforming to Formula 2B of
successive 3-mL washes of n-pentane. Add each wash to the
theU.S.BureauofInternalRevenue.(Warning—Flammable.)
topofthecolumn.Thenrinsethewallsofthecolumnbulbwith
two 3-mL portions of n-pentane, allowing the liquid level to
7.7 Pressuring Gas, dry air or nitrogen, delivered to the top
of the column at a regulated gage pressure of 0 to 2 psi (13.8 reach the top of the bauxite bed before adding the next portion.
Finally add 35 mL of n-pentane to the column bulb.
kPa). (Warning— Compressed gas.)
8.4.3 Place a 50-mL graduate beneath the column to collect
7.8 n-Pentane, commercial grade, aromatic-free. Some
theeluate.Theelutionrateshouldbeapproximately1mL/min.
samples of waxy stocks may not dissolve completely in
n-pentane, in which case cyclohexane, commercial grade,
NOTE 4—Gas pressure (Warning—Compressed gas) can be applied to
aromatic-free, may be substituted for n-pentane. (Warning— the top of the column as necessary to maintain the elution rate at
approximately 1 mL/min. If the correct pressure setting is known from
Extremely flammable liquid.)
previous runs, gas pressure may be applied after addition of the last
7.9 Silica Gel, 100 to 200-mesh.
increment of n-pentane. Otherwise, gas pressure should be applied when
n-pentane begins to elute from the column and should be adjusted to give
a flow rate of approximately 1 mL/min.
8. Procedure
NOTE 3—The procedural details differ depending on the initial boiling
8.4.4 When the n-pentane level reaches the top of the
point of the sample. If the 5 % point is above 178°C (350°F), but below
bauxitebed,add80mLofdiethylether(Warning—Extremely
232°C (450°F), use procedure described in Appendix X1. If above 232°C,
flammable). Connect the pressuring gas to the top of the
continue as written depending on amount of sample to be analyzed.
column and adjust the pressure to maintain an elution rate of 1
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. to 2 mL/min.
8.4.5 Collect 50 mL of n-pentane eluate in the graduate.
8.1 Select the appropriate column, depending on whether 2
Rinsethetipofthecolumnwith1to2mLofn-pentane,adding
or 10 g of sample are to be analyzed. Clean the column with
this to the 50 mL in the graduate (Note 5). Label the 50-mL
chromic-sulfuric acid (Warning—Causes severe burns), fol-
graduate as n-pentane eluate.
lowed by distilled or demineralized water, acetone, and dry air
or nitrogen.
NOTE 5—The n-pentane will have reached the adsorbent bed before the
required volume of eluate has been collected in the 50-mL receiver.
8.2 Introduce a small plug of glass wool into the column,
Continue collection in this receiver after the addition of ether until the
pressingitfirmlyintothelowerendtopreventtheflowofsilica
proper volume has been collected before changing to the 100-mL
gel from the column.
graduate.
8.3 Clamp the column in a vertical position. Add small
8.4.6 When the ether level reaches the top of the bauxite
increments of silica gel, while vibrating the column along its
bed, release the gas pressure and add 100 mL of chloroform
length, until the tightly packed silica gel extends to the lower
(Warning—Toxic. May be fatal if swallowed) to the top of the
mark on the chromatographic column. Continue to vibrate the
column. Reconnect the gas pressuring system and continue the
column and add bauxite until the bauxite layer extends to the
elution. When 80 mL of eluate have been collected in the
upper mark on the chromatographic column. Vibrate the
graduate, rinse the column tip with 1 mL of ether and add the
column for an additional 3 min after filling is completed.
rinse to the 100-mLgraduate. Change the receiver to a 250-mL
graduate. Label the 100-mL graduate as ether-eluted fraction.
8.4 If2gof sample are to be analyzed, continue as in 8.4.1,
8.4.7 When the chloroform level reaches the top of the
otherwise continue as in 8.5.
bauxite bed, release the gas pressure and add 75 mL of ethyl
8.4.1 If the sample is viscous, warm it with intermittent
alcohol (Warning—Flammable liquid). Reconnect the gas
mixing or shaking until it is completely fluid. Transfer a
pressuring system and continue the elution until the alcohol
representative sample (approximately 2 g) to a 25-mL weigh-
level reaches the top of the bauxite bed. Release the gas
ing bottle or flask. Determine the weight of the sample to the
pressure.Rinsethecolumntipwith1mLofchloroformadding
nearest 1 mg by weighing the flask before and after sample
this to the graduate. Label the 250-mLgraduate as chloroform-
transfer. Add 10 mL of n-pentane (Warning—Extremely
alcohol-eluted fraction.
flammable liquid), to the flask and dissolve the sample. If the
8.4.8 Weigh a 100-mL inverted-rim beaker to the nearest 1
mg. Quantitatively transfer the n-pentane eluate to this beaker
and allow the n-pentane to evaporate at room temperature.
The sole source of supply of the silica gel known to the committee at this time
is W.R. Grace and Co., Davison Chemical Div., Baltimore, MD 21203, by
Cyclohexane, if used as the elution solvent, is evaporated on a
specifying Code 923. If you are aware of alternative suppliers, please provide this
steam bath. Evaporation is accelerated in both cases by
information to ASTM International Headquarters. Your comments will receive
directing a controlled stream of dry nitrogen downward onto
careful consideration at a meeting of the responsible technical committee , which
you may attend. the surface of the liquid.
D2549 − 02 (2012)
after addition of the last increment of n-pentane. Otherwise, gas pressure
8.4.9 When all the solvent appears to be evaporated, stop
should be applied when n-pentane begins to elute from the column and
the nitrogen flow, allow the beaker to come to room
should be adjusted to give a flow rate of approximately 3 mL/min.
temperature, and dry the outside of the beaker to remove any
8.5.4 When the n-pentane level reaches the top of the
condensed moisture. Reweigh the beaker to the nearest 1 mg.
bauxite bed, add 100 mL of diethyl ether. Connect the
NOTE 6—Complete solvent evaporation is indicated by a tendency of
pressuring gas to the top of the column and adjust the pressure
the oil to creep up the side of the beaker.
to maintain an elution rate of 3 to 5 mL/min.
8.4.10 Repeat the evaporation step for 5-min periods until
8.5.5 Collect 130 mLof eluate in the graduate. Rinse the tip
theweightlossbetweensuccessiveevaporationsislessthan20
of the column with 1 to 2 mL of n-pentane, adding this to the
mg. Heat from a steam bath is generally required during the
130 mL in the graduate. Change the receiver to a 100-mL
final evaporation steps to remove completely the elution
graduate (Note 8). Label the 200-mL graduate as n-pentane
solvent. The weight of the residue in the beaker is the quantity
eluate.
of the nonaromatics fra
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