ASTM D7373-07
(Test Method)Standard Test Method for Predicting Biodegradability of Lubricants Using a Bio-kinetic Model
Standard Test Method for Predicting Biodegradability of Lubricants Using a Bio-kinetic Model
SIGNIFICANCE AND USE
This procedure is able to predict the biodegradability of lubricants within a day without dealing with microorganisms.3 Excellent correlation is established between the test results and the conventional biodegradation tests (see Test Method D 5864 and Test Method D 6731).
SCOPE
1.1 This test method covers a procedure for predicting biodegradability of lubricants using a bio-kinetic.
1.2 the values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D7373–07
Standard Test Method for
Predicting Biodegradability of Lubricants Using
a Bio-kinetic Model
This standard is issued under the fixed designation D7373; 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 3.1.4 effective composition to biodegradation (ECB),
n—component of material that can be biodegradable by
1.1 This test method covers a procedure for predicting
bacteria.
biodegradability of lubricants using a bio-kinetic model.
3.1.4.1 Discussion—The term ECB is a part of bio-kinetic
1.2 The values stated in SI units are to be regarded as
model is sum of non-aromatic components in a lubricant.
standard. The values given in parentheses are for information
3.1.5 nonaromatics fraction, n—portion of the sample
only.
eluted with n-pentane. The nonaromatics fraction is a mixture
1.3 This standard does not purport to address all of the
of paraffinic and naphthenic hydrocarbons if sample is a
safety concerns, if any, associated with its use. It is the
straight-run material. If the sample is a cracked stock, the
responsibility of the user of this standard to establish appro-
nonaromatics fraction will also contain aliphatic and cyclic
priate safety and health practices and determine the applica-
olefins.
bility 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
D2549 Test Method for Separation of Representative Aro-
and silica gel. To elute the nonaromatics, n-pentane is added to
matics and Nonaromatics Fractions of High-Boiling Oils
thecolumn.Whenallofthenonaromaticsareeluted,non-polar
by Elution Chromatography
aromatics fraction is eluted by additions of an equal mixture of
D5864 Test Method for Determining Aerobic Aquatic Bio-
toluene and n-pentane. The ester fraction is eluted by additions
degradation of Lubricants or Their Components
of diethyl ether. Then, the polar-aromatics is eluted by chloro-
D6731 Test Method for Determining the Aerobic, Aquatic
form and ethyl alcohol.
Biodegradability of Lubricants or Lubricant Components
4.2 The solvents are completely removed by evaporation,
in a Closed Respirometer
and the residues are weighed and calculated as the nonaromat-
3. Terminology ics, nonpolar aromatics, ester fractions, and polar aromatics of
the sample.
3.1 Definitions:
4.3 ECB is calculated based on the amount of nonaromatics
3.1.1 aromatics fraction, n—portion of the sample desorbed
and ester fractions with their material ECB coefficients. Then,
with the polar eluants. The aromatics fraction is divided into
the biodegradability of a lubricant is calculated using the
nonpolar and polar based. They may contain aromatics, con-
bio-kinetic model.
densed naphthenic-aromatics, aromatic olefins, and com-
pounds containing sulfur, nitrogen, and oxygen atoms.
5. Significance and Use
3.1.2 bio-kinetic model, n—model that can predict the
5.1 This procedure is able to predict the biodegradability of
biodegradability of a lubricant.
lubricants within a day without dealing with microorganisms.
3.1.3 biodegradability, n—ability of a substance to be
Excellent correlation is established between the test results and
broken down into simpler substances by bacteria.
the conventional biodegradation tests (see Test Method D5864
and Test Method D6731).
This test method is under the jurisdiction of ASTM Committee D02 on
6. Apparatus
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.12 on Environmental Standards for Lubricants. 6.1 Chromatographic Columns—as shown in Fig. 1 (see
Current edition approved July 15, 2007. Published August 2007. DOI: 10.1520/
Test Method D2549).
D7373-07.
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 Rhee, In-Sik, “Development of Bio-kinetic Model for Lubricants,” NLGI
the ASTM website. Spokesman, Volume 69, 2005, pp. 22-29.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7373–07
FIG. 1 Test Apparatus
6.2 Beakers (100, 250, and 600-mL)—inverted-rim type. free of peroxides as determined by the procedure in Reagent
Chemicals, American Chemical Society Specifications.
6.3 Steam Bath.
7.6 Ethyl Alcohol, Denatured—Conforming to Formula 2B
6.4 Electric Vibrator—for packing column.
of the U.S. Bureau of Internal Revenue. (Warning—
6.5 Weighing Bottles or Erlenmeyer Flasks—25 and 50 mL.
Flammable.)
6.6 Graduated Cylinders—50 mL, 100 mL, and 250 mL.
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
7. Reagents and Materials
(13.8 kPa). (Warning—Compressed gas.)
7.1 Purity of Reagents—Reagent grade chemicals shall be
7.8 n-pentane—Commercial grade, aromatic–free. Some
used in this test. Unless otherwise indicated, it is intended that
samples of waxy stocks may not dissolve completely in
all reagents shall conform to the specifications of the Commit-
n-pentane, in which case cyclohexane, commercial grade,
tee onAnalytical Reagents of theAmerican Chemical Society,
aromatic-free, may be substituted for n-pentane. (Warning—
where such specifications are available. Other grades may be
Extremely flammable liquid.)
used, provided it is first ascertained that the reagent is of
7.9 Silica Gel—100- to 200-mesh.
sufficiently high purity to permit its use without lessening the
7.10 Toluene—Reagent grade minimum purity.
accuracy of the determination.
(Warning—Toluene is flammable. Vapor harmful.)
7.2 Bauxite, 20- to 60-mesh—Before use, activate the baux-
8. Procedure for Composition Analysis
ite by heating at 538°C (1000°F) for 16 h. Transfer the
activated material to an airtight container while still hot and 8.1 Clean the column with chromic-sulfuric acid (7.4),
protect thereafter from atmospheric moisture. followed by distilled or demineralized water, acetone, and dry
air or nitrogen.
7.3 Chloroform—(Warning—Toxic. May be fatal if swal-
lowed.)
7.4 Cleaning Solution—Chromic-sulfuric acid.
Reagent Chemicals, American Chemical Society Specifications, American
(Warning—Causes severe burns. A recognized carcinogen, Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
listed by the American Chemical Society, see Annual Standards for Laboratory
strong oxidizer, contact with organic material may cause fire.)
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
7.5 Diethyl Ether—Anhydrous. (Warning—Extremely
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
flammable.) The ethyl ether used in this test method should be MD.
D7373–07
8.2 Introduce a small plug of glass wool into column, 8.16 Whentheetherlevelreachesthetopofthebauxitebed,
pressingitfirmlyintothelowerendtopreventtheflowofsilica release the gas pressure and add 100 mLof chloroform (7.3)to
gel from the column. thetopofthecolumn.Reconnectthegaspressuringsystemand
8.3 Clamp the column in a vertical position. Add small continue the elution. When 80 mL of eluate have been
increments of silica gel, while vibrating the column along its collected in the graduate, rinse the column tip with 1 mL of
length, until the tightly packed silica gel extends to the lower ether and add the rinse to the 100 mL graduate. Change the
mark on the chromatographic column. receiver to a 250 mL graduate. Label the 100 mL graduate as
8.4 Continue to vibrate the column and add bauxite until the ether-eluted fraction.
8.17 When the chloroform level reaches the top of the
bauxite layer extends to the upper mark on the chromato-
graphic column. Vibrate the column for an additional 3 min bauxite bed, release the gas pressure and add 75 mL of ethyl
after filling is completed alcohol (
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