ASTM D2007-11(2016)
(Test Method)Standard Test Method for Characteristic Groups in Rubber Extender and Processing Oils and Other Petroleum-Derived Oils by the Clay-Gel Absorption Chromatographic Method
Standard Test Method for Characteristic Groups in Rubber Extender and Processing Oils and Other Petroleum-Derived Oils by the Clay-Gel Absorption Chromatographic Method
SIGNIFICANCE AND USE
5.1 The composition of the oil included in rubber compounds has a large effect on the characteristics and uses of the compounds. The determination of the saturates, aromatics, and polar compounds is a key analysis of this composition.
5.2 The determination of the saturates, aromatics, and polar compounds and further analysis of the fractions produced is often used as a research method to aid understanding of oil effects in rubber and other uses.
SCOPE
1.1 This test method covers a procedure for classifying oil samples of initial boiling point of at least 260 °C (500 °F) into the hydrocarbon types of polar compounds, aromatics and saturates, and recovery of representative fractions of these types. This classification is used for specification purposes in rubber extender and processing oils.
Note 1: See Test Method D2226.
1.2 This test method is not directly applicable to oils of greater than 0.1 % by mass pentane insolubles. Such oils can be analyzed after removal of these materials, but precision is degraded (see Appendix X1).
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information 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 health practices and determine the applicability of regulatory limitations prior to use. Specific warning statements are given in 6.1, Section 7, A1.4.1, and A1.5.5.
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Designation: D2007 − 11 (Reapproved 2016)
Standard Test Method for
Characteristic Groups in Rubber Extender and Processing
Oils and Other Petroleum-Derived Oils by the Clay-Gel
Absorption Chromatographic Method
This standard is issued under the fixed designation D2007; 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 3. Terminology
3.1 Definitions of Terms Specific to This Standard:
1.1 This test method covers a procedure for classifying oil
samples of initial boiling point of at least 260 °C (500 °F) into 3.1.1 The following terms refer to the hydrocarbon types
the hydrocarbon types of polar compounds, aromatics and and structural groups as measured by this test method:
saturates, and recovery of representative fractions of these 3.1.2 aromatics—material that, on percolation, passes
types. This classification is used for specification purposes in through a column of adsorbent clay in a n-pentane eluent but
rubber extender and processing oils. adsorbs on silica gel under the conditions specified.
3.1.3 asphaltenes, or n-pentane insolubles—insoluble mat-
NOTE 1—See Test Method D2226.
ter that precipitates from a solution of oil in n-pentane under
1.2 This test method is not directly applicable to oils of
the specified conditions.
greater than 0.1 % by mass pentane insolubles. Such oils can
3.1.4 polar aromatics—synonym for polar compounds.
be analyzed after removal of these materials, but precision is
3.1.5 polar compounds—material retained on adsorbent
degraded (see Appendix X1).
clay after percolation of the sample in n-pentane eluent under
1.3 The values stated in SI units are to be regarded as the
the conditions specified.
standard. The values given in parentheses are for information
3.1.6 saturates—material that, on percolation in a n-pentane
only.
eluent, is not adsorbed on either the clay or silica gel under the
1.4 This standard does not purport to address all of the
conditions specified.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 4. Summary of Test Method
priate safety and health practices and determine the applica-
4.1 The sample is diluted with solvent and charged to a
bility of regulatory limitations prior to use. Specific warning
glass percolation column containing clay in the upper section
statements are given in 6.1, Section 7, A1.4.1, and A1.5.5.
and silica gel plus clay in the lower section. n-pentane is then
charged to the double column until a definite quantity of
2. Referenced Documents
effluenthasbeencollected.Theupper(clay)sectionisremoved
from the lower section and washed further with n-pentane. A
2.1 ASTM Standards:
toluene-acetone mixture 50 to 50 by volume is then charged to
D2226 Classification for Various Types of Petroleum Oils
the clay section for desorption and a specified volume of
for Rubber Compounding Use
effluent collected. The lower (gel) column may be desorbed by
D5309 Specification for Cyclohexane 999
recirculation of toluene.
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
4.2 The solvents are completely removed from the recov-
ered n-pentane and the toluene-acetone fractions and the
residues are weighed and calculated as saturate and polar
1 compounds contents. Aromatics may be calculated by
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of difference, or measured following evaporation of the toluene
Subcommittee D02.04.0C on Liquid Chromatography.
used for desorption of the gel column.
Current edition approved Oct. 1, 2016. Published November 2016. Originally
4.3 When the sample contains more than 0.1 % by mass of
approved in 1968. Last previous edition approved in 2011 as D2007 – 11. DOI:
10.1520/D2007-11R16.
n-pentane insolubles, this test method cannot be used directly.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Theinsolublemattermustberemovedfromthesamplepriorto
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
charging to the column. A method for this removal is given as
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. an appendix.
*A Summary of Changes 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
D2007 − 11 (2016)
approximately 6 mm thick, included under or on top of regular plate top.
4.4 Alternative methods are provided (1) for recovery of
aromatics from the gel column, and (2) for analysis of oil with
6.8 Round Bottom Flask, 3-necked, borosilicate, 500 mL
high-polar content.
capacity (Fig. 3).
6.9 Condenser, borosilicate (Fig. 3).
5. Significance and Use
3,4
5.1 The composition of the oil included in rubber com-
6.10 Adapter Tube with Vigreux column (Fig. 3).
pounds has a large effect on the characteristics and uses of the
6.11 Flexible Joint, TFE-fluorocarbon and borosilicate,
compounds. The determination of the saturates, aromatics, and
4,5
24/40 T ground glass joints on each end.
S
polar compounds is a key analysis of this composition.
5.2 The determination of the saturates, aromatics, and polar
7. Reagents and Materials
compounds and further analysis of the fractions produced is
7.1 Purity of Reagents, Reagent grade chemicals shall be
often used as a research method to aid understanding of oil
used in all tests. Unless otherwise indicated, it is intended that
effects in rubber and other uses.
all reagents shall conform to the specifications of the commit-
tee onAnalytical Reagents of theAmerican Chemical Society,
6. Apparatus
where such specifications are available. Other grades may be
6.1 Beakers, Anticreep, 150-mL capacity, as illustrated in
used, provided it is first ascertained that the reagent is of
Fig. 1.(Warning—Beakers should be examined for sharp
sufficiently high purity to permit its use without lessening the
edges and fire polished, if necessary.)
accuracy of the determination.
6.2 Clay-Gel Column, constructed as illustrated in Fig. 2.
7.2 Acetone, reagent grade, minimum purity. (Warning—
6.3 Conical Flasks, (Erlenmeyer), 250 mL capacity.
Acetone is extremely flammable.)
6.4 Solvent Receiver, capable of collecting solvent, without
7.3 Calcium Chloride, anhydrous granules.
splashing or loss of material during the analysis. A wide-
7.4 Clay Adsorbent, 500 µm to 250 µm (30 mesh to 60
mouth, graduated, 500 mL capacity Erlenmeyer flask is one
4,7
mesh)Attapulgus. Clay quality may be determined using the
such example that has been found suitable to use.
azobenzene equivalence test shown in AnnexA1. The azoben-
6.5 Filter Funnel,longstem,125 mmdiameter;forusewith
zene activity test measures the adsorptive characteristics of the
185 mm ready folded, fine-texture, rapid filter paper.
clay. Azobenzene equivalence value should be 30 to 35. Clay
6.6 Separatory Funnel, 500 mL. outside of these limits should be discarded.
6.7 Hot Plate, explosion proof, controlled to a surface
7.5 Cyclohexane, conforming to Specification D5309.
temperature of 100 °C to 105 °C.
(Optional, see 8.1.9.) (Warning—Cyclohexane is extremely
flammable. Harmful if inhaled.)
NOTE 2—Temperatures should be uniform on the top of the hot plate.
4,8
Some laboratory hot plates benefit by the inclusion of an aluminum plate,
7.6 Pentane, reagent grade minimum purity. (Warning—
n-Pentane is extremely flammable. Harmful if inhaled.)
7.7 Silica Gel, activated, conforming to the following
4,9
inspections:
The sole source of supply of the adapter tube known to the committee at this
timeisOwensGlassApparatus,Inc.,128RiverRoad,Channelview,TX77530.This
item can be fabricated at any scientific glassblowing shop.
If you are aware of alternative suppliers, please provide this information to
ASTM International Headquarters. Your comments will receive careful consider-
ation at a meeting of the responsible technical committee, which you may attend.
Cole Parmer No. 6675-40 has been found suitable for this purpose.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
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,
MD.
Thesolesourceofsupplyofclayadsorbentknowntothecommitteeatthistime
is Forcoven Products, 22010 East Martin Dr., Porter, TX 77365. Packaged in
moisture resistant twinned packets of 50 and 100 g (sufficient for one determina-
tion). These packets are packed 50 sets per case. It is important that extremes of
temperature be avoided on stored clay samples.
The sole source of supply of pentane known to the committee at this time is
Special Products Div., Phillips Petroleum Co., Bartlesville, OK.
The sole source of supply of silica gel meeting these specifications known to
the committee at this time is Forcoven Products, 22010 East Martin Dr., Porter, TX
77365, packaged in 200 g moisture resistant packets. Sieve analysis should be
FIG. 1 Anticreep Beaker checked on other sources of gel.
D2007 − 11 (2016)
NOTE 1—Check to ascertain ID is 44 mm.
FIG. 2 Clay-Gel Percolating Column
the eluent solvents. Join the columns (clay over gel) after
Sieve analysis >30 sieve size, 5 % (mass) maximum;
>50 sieve size, 45 % (mass) min
lubricating the joint with hydrocarbon-insoluble grease. It is
>100 sieve size, 80 % (mass) min
important that the adsorbents in each column be packed to a
>200 sieve size, 94 % (mass) min
constant level. A minimum of ten taps with a soft rubber
7.7.1 Gel should be activated for 4 h in an air oven at
hammer at different points up and down and 25 taps on top of
190 °C in a shallow pan.
each column should be employed to achieve constant level. A
7.8 Toluene, reagent grade minimum purity. (Warning—
suitable rubber hammer may be assembled by fastening two
Toluene is flammable. Vapor harmful.)
No. 7 or 8 rubber stoppers on one end of a small rod about
200 mm long. Use fresh adsorbents for each determination.
7.9 Toluene-Acetone Mixture (50 to 50 by volume), mix
8.1.2 If n-pentaneinsolubleswerenotdetermined,selectthe
equal volumes of toluene and acetone.
appropriate sample size in accordance with the following polar
7.10 In order to obtain results that are consistent with those
content ranges, if the proper range can be anticipated;
obtained elsewhere, it is very important that only the reagents
otherwise, use a 10 g 6 0.5 g sample.
and materials described in this section be used.
Polar Content Range,
mass percent Sample Size, g
8. Procedure
0–20 10 ± 0.5
Above 20 5 ± 0.2
8.1 Fractionation:
8.1.1 Prepare the adsorption column (Fig. 2) by placing 8.1.3 Dilute with 25 mLof n-pentane solvent and mix well
100 g of clay adsorbent in the upper section of the column and to ensure a uniform solution of the sample. The sample should
200 g of silica gel plus 50 g of clay on top of the gel in the notdisplayprecipitateorflocculateatthispoint.Ifaprecipitate
lower section (Note 5). Place a piece of glass wool (of about is present asphaltenes may be removed by the procedure of
25 mm loose thickness) over the top surface of the clay in the Appendix X1, however, the precision statement no longer
upper column to prevent agitation of the clay while charging applies. It is important that the polar content result obtained be
D2007 − 11 (2016)
8.1.5 When nearly all of the washings have entered the clay,
charge n-pentane to the column and maintain a head level well
above the clay beds (Note 4) to wash the saturateportionofthe
sample from the adsorbents. Recover 280 mL 6 10 mL of the
firstn-pentaneeffluentfromthecolumninagraduated,500 mL
wide-mouth conical flask.
NOTE 4—Columns may be briefly separated, if necessary, to give a
solvent head 5 mm to 10 mm deep in the second (lower) column. Loss of
theheadwillgivechannelinginthelowercolumn,withinaccurateresults.
NOTE 5—With long use, the frits in the absorption columns become
progressively less porous. If the time for percolation doubles over that for
a new column, the slow columns are to be discarded.
NOTE 6—If only saturates are to be determined, proceed to 8.3 and
subsequent calculation of saturates.
8.1.6 Disconnect the two sections. Allow the lower section
to drain into a receiver. Continue washing the upper clay
section with n-pentane. Maintain a moderate liquid head level
above the clay during this wash and adjust n-pentane additions
so that the level is about 25 mm when 150 mL have been
collectedinthereceiver.Discontinueadditionsatthispointand
allow the liquid to essentially drain from the column. The
quantity in the receiver should then be about 200 mL. The
n-pentane from this step and from the draining of the lower
column should be discarded if aromatics are to be determined
by difference. This n-pentane should be added to the aromatics
solution from the gel column during solvent evaporation (8.3)
if aromatics are to be recovered.
NOTE 7—This extra n-pentane washing of the clay section is necessary
in order to ensure complete removal of aromatics from the clay.
8.1.7 After n-pentane effluent has essentially drained from
the column, charge a 50 to 50 volume mixture of toluene–ac-
etone. Collect the effluent in a 500 mL separatory funnel.
Collect250 mLofthetoluene-acetone(plusn-pentane)effluent
or until the effluent is practically colorless (only in exceptional
FIG. 3 Extraction Apparatus
cases will more than 300 mL of effluent be required).
8.1.8 Stopper the separatory funnel containing the toluene-
acetone fraction and swirl it a few times to aid in settling the
not greater than that for the sample size as specified above,
water. Then let it stand for about 5 min. Drain off and discard
since the capacity of the clay for retaining polar constituents
the lower (aqueous) layer. Add approximately 10 g of anhy-
becomes limited at these concentrations. If results exceed this
drouscalciumchloridegranulestothefractionremaininginthe
specification, repeat the test using a smaller sample. Partition-
separatory funnel and shake for about 30 s; vent frequently
ing between aromatics and polar compounds is affected by
during the shaking period. Allow the mixture to settle for at
...
This 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 version. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation: D2007 − 11 D2007 − 11 (Reapproved 2016)
Standard Test Method for
Characteristic Groups in Rubber Extender and Processing
Oils and Other Petroleum-Derived Oils by the Clay-Gel
Absorption Chromatographic Method
This standard is issued under the fixed designation D2007; 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*Scope
1.1 This test method covers a procedure for classifying oil samples of initial boiling point of at least 260°C (500°F)260 °C
(500 °F) into the hydrocarbon types of polar compounds, aromatics and saturates, and recovery of representative fractions of these
types. This classification is used for specification purposes in rubber extender and processing oils.
NOTE 1—See Test Method D2226.
1.2 This test method is not directly applicable to oils of greater than 0.1 mass % pentane0.1 % by mass pentane insolubles. Such
oils can be analyzed after removal of these materials, but precision is degraded (see Appendix X1).
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information 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 health practices and determine the applicability of regulatory
limitations prior to use. Specific warning statements are given in 6.1, Section 7, A1.4.1, and A1.5.5.
2. Referenced Documents
2.1 ASTM Standards:
D2226 Classification for Various Types of Petroleum Oils for Rubber Compounding Use
D5309 Specification for Cyclohexane 999
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 The following terms refer to the hydrocarbon types and structural groups as measured by this test method:
3.1.2 aromatics—material that, on percolation, passes through a column of adsorbent clay in a n-pentane eluent but adsorbs on
silica gel under the conditions specified.
3.1.3 asphaltenes, or n-pentane insolubles—insoluble matter that precipitates from a solution of oil in n-pentane under the
specified conditions.
3.1.4 polar aromatics—synonym for polar compounds.
3.1.5 polar compounds—material retained on adsorbent clay after percolation of the sample in n-pentane eluent under the
conditions specified.
3.1.6 saturates—material that, on percolation in a n-pentane eluent, is not adsorbed on either the clay or silica gel under the
conditions specified.
4. Summary of Test Method
4.1 The sample is diluted with solvent and charged to a glass percolation column containing clay in the upper section and silica
gel plus clay in the lower section. n-pentane is then charged to the double column until a definite quantity of effluent has been
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.04.0C on Liquid Chromatography.
Current edition approved May 1, 2011Oct. 1, 2016. Published June 2011November 2016. Originally approved in 1968. Last previous edition approved in 20082011 as
D2007–03(2008).D2007 – 11. DOI: 10.1520/D2007-11.10.1520/D2007-11R16.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes 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
D2007 − 11 (2016)
collected. The upper (clay) section is removed from the lower section and washed further with n-pentane. A toluene-acetone
mixture 50 to 50 by volume is then charged to the clay section for desorption and a specified volume of effluent collected. The
lower (gel) column may be desorbed by recirculation of toluene.
4.2 The solvents are completely removed from the recovered n-pentane and the toluene-acetone fractions and the residues are
weighed and calculated as saturate and polar compounds contents. Aromatics may be calculated by difference, or measured
following evaporation of the toluene used for desorption of the gel column.
4.3 When the sample contains more than 0.1 0.1 % by mass % of n-pentane insolubles, this test method cannot be used directly.
The insoluble matter must be removed from the sample prior to charging to the column. A method for this removal is given as an
appendix.
4.4 Alternative methods are provided (1) for recovery of aromatics from the gel column, and (2) for analysis of oil with
high-polar content.
5. Significance and Use
5.1 The composition of the oil included in rubber compounds has a large effect on the characteristics and uses of the compounds.
The determination of the saturates, aromatics, and polar compounds is a key analysis of this composition.
5.2 The determination of the saturates, aromatics, and polar compounds and further analysis of the fractions produced is often
used as a research method to aid understanding of oil effects in rubber and other uses.
6. Apparatus
6.1 Beakers, Anticreep, 150-mL capacity, as illustrated in Fig. 1. (Warning—Warning—Beakers should be examined for sharp
edges and fire polished, if necessary.)
6.2 Clay-Gel Column, constructed as illustrated in Fig. 2.
6.3 Conical Flasks, (Erlenmeyer), 250-mL250 mL capacity.
6.4 Solvent Receiver, capable of collecting solvent, without splashing or loss of material during the analysis. A wide-mouth,
graduated, 500-mL500 mL capacity Erlenmeyer flask is one such example that has been found suitable to use.
6.5 Filter Funnel, long stem, 125-mm125 mm diameter; for use with 185 mm ready folded, fine-texture, rapid filter paper.
6.6 Separatory Funnel, 500 mL.500 mL.
6.7 Hot Plate, explosion proof, controlled to a surface temperature of 100100 °C to 105°C.105 °C.
NOTE 2—Temperatures should be uniform on the top of the hot plate. Some laboratory hot plates benefit by the inclusion of an aluminum plate,
approximately 6-mm6 mm thick, included under or on top of regular plate top.
FIG. 1 Anticreep Beaker
D2007 − 11 (2016)
NOTE 1—Check to ascertain ID is 44 mm.44 mm.
FIG. 2 Clay-Gel Percolating Column
6.8 Round Bottom Flask, 3-necked, borosilicate, 500-mL500 mL capacity (Fig. 3).
6.9 Condenser, borosilicate (Fig. 3).
3,4
6.10 Adapter Tube with Vigreux column (Fig. 3).
4,5
6.11 Flexible Joint, TFE-fluorocarbon and borosilicate, 24/40 T ground glass joints on each end.
S
7. Reagents and Materials
7.1 Purity of Reagents, Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the committee on Analytical Reagents of the American Chemical Society, where
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
7.2 Acetone, reagent grade, minimum purity. (Warning—WarningAcetone—Acetone is extremely flammable.)
7.3 Calcium Chloride, anhydrous granules.
The sole source of supply of the adapter tube known to the committee at this time is Owens Glass Apparatus, Inc., 128 River Road, Channelview, TX 77530. This item
can be fabricated at any scientific glassblowing shop.
If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a
meeting of the responsible technical committee, which you may attend.
Cole Parmer No. 6675-40 has been found suitable for this purpose.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not 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, MD.
D2007 − 11 (2016)
FIG. 3 Extraction Apparatus
4,7
7.4 Clay Adsorbent, 500 to 250 μm (30 500 μm to 250 μm (30 mesh to 60 mesh) Attapulgus. Clay quality may be determined
using the azobenzene equivalence test shown in Annex A1. The azobenzene activity test measures the adsorptive characteristics
of the clay. Azobenzene equivalence value should be 30 to 35. Clay outside of these limits should be discarded.
7.5 Cyclohexane, conforming to Specification D5309. (Optional, see 8.1.9.) (Warning—WarningCyclohexane—Cyclohexane
is extremely flammable. Harmful if inhaled.)
4,8
7.6 Pentane, reagent grade minimum purity. (Warning—Warning—n-Pentane is extremely flammable. Harmful if inhaled.)
4,9
7.7 Silica Gel, activated, conforming to the following inspections:
Sieve analysis >30 sieve size, 5 % (mass) maximum;
>50 sieve size, 45 % (mass) min
>100 sieve size, 80 % (mass) min
>200 sieve size, 94 % (mass) min
7.7.1 Gel should be activated for 4 h 4 h in an air oven at 190°C190 °C in a shallow pan.
7.8 Toluene, reagent grade minimum purity. (Warning—WarningToluene—Toluene is flammable. Vapor harmful.)
7.9 Toluene-Acetone Mixture (50 to 50 by volume), mix equal volumes of toluene and acetone.
The sole source of supply of clay adsorbent known to the committee at this time is Forcoven Products, 22010 East Martin Dr., Porter, TX 77365. Packaged in moisture
resistant twinned packets of 50 and 100 g (sufficient for one determination). These packets are packed 50 sets per case. It is important that extremes of temperature be avoided
on stored clay samples.
The sole source of supply of pentane known to the committee at this time is Special Products Div., Phillips Petroleum Co., Bartlesville, OK.
The sole source of supply of silica gel meeting these specifications known to the committee at this time is Forcoven Products, 22010 East Martin Dr., Porter, TX 77365,
packaged in 200 g moisture resistant packets. Sieve analysis should be checked on other sources of gel.
D2007 − 11 (2016)
7.10 In order to obtain results that are consistent with those obtained elsewhere, it is very important that only the reagents and
materials described in this section be used.
8. Procedure
8.1 Fractionation:
8.1.1 Prepare the adsorption column (Fig. 2) by placing 100 g 100 g of clay adsorbent in the upper section of the column and
200 g 200 g of silica gel plus 50 g 50 g of clay on top of the gel in the lower section (Note 5). Place a piece of glass wool (of
about 25-mm25 mm loose thickness) over the top surface of the clay in the upper column to prevent agitation of the clay while
charging the eluent solvents. Join the columns (clay over gel) after lubricating the joint with hydrocarbon-insoluble grease. It is
important that the adsorbents in each column be packed to a constant level. A minimum of ten taps with a soft rubber hammer at
different points up and down and 25 taps on top of each column should be employed to achieve constant level. A suitable rubber
hammer may be assembled by fastening two No. 7 or 8 rubber stoppers on one end of a small rod about 200-mm200 mm long.
Use fresh adsorbents for each determination.
8.1.2 If n-pentane insolubles were not determined, select the appropriate sample size in accordance with the following polar
content ranges, if the proper range can be anticipated; otherwise, use a 1010 g 6 0.5 g 0.5 g sample.
Polar Content Range,
mass percent Sample Size, g
0–20 10 ± 0.5
Above 20 5 ± 0.2
8.1.3 Dilute with 25 mL 25 mL of n-pentane solvent and mix well to ensure a uniform solution of the sample. The sample
should not display precipitate or flocculate at this point. If a precipitate is present asphaltenes may be removed by the procedure
of Appendix X1, however, the precision statement no longer applies. It is important that the polar content result obtained be not
greater than that for the sample size as specified above, since the capacity of the clay for retaining polar constituents becomes
limited at these concentrations. If results exceed this specification, repeat the test using a smaller sample. Partitioning between
aromatics and polar compounds is affected by sample size. Results using different sample size may not be equivalent.
NOTE 3—For viscous oils, dilutions of the sample with 25 mL 25 mL of cyclohexane is more convenient and does not affect the results. Cyclohexane
used in this manner will not detect small quantities of asphaltenes, however.
8.1.4 Add 25 mL 25 mL of n-pentane to the top of the clay portion of the assembled column and allow to percolate into the
clay. As soon as nearly all of the n -pentane has entered the clay, charge to the column the diluted sample of 8.1.3. Wash the sample
beaker (or flask) with n-pentane and add the washings to the column. After nearly all of this material has entered the clay, wash
the walls of the column above the clay free of sample with n-pentane. The sample and eluent solvent can be added to the column
through a 65-mm65 mm diameter, wide-stem funnel (the funnel can be left on top of the column). At no time during the run should
air be allowed to enter the clay bed.
8.1.5 When nearly all of the washings have entered the clay, charge n-pentane to the column and maintain a head level well
above the clay beds (Note 4) to wash the saturate portion of the sample from the adsorbents. Recover 280280 mL 6 10 mL 10 mL
of the first n-pentane effluent from the column in a graduated, 500-mL500 mL wide-mouth conical flask.
NOTE 4—Columns may be briefly separated, if necessary, to give a solvent head 5-5 mm to 10-mm10 mm deep in the second (lower) column. Loss
of the head will give channeling in the lower column, with inaccurate results.
NOTE 5—With long use, the frits in the absorption columns become progressively less porous. If the time for percolation doubles over that for a new
column, the slow columns are to be discarded.
NOTE 6—If only saturates are to be determined, proce
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