ASTM D2896-15

Standard Test Method for Base Number of Petroleum Products by Potentiometric Perchloric Acid Titration

SIGNIFICANCE AND USE
5.1 New and used petroleum products can contain basic constituents that are present as additives. The relative amounts of these materials can be determined by titration with acids. The base number is a measure of the amount of basic substance in the oil, always under the conditions of the test. It is sometimes used as a measure of lubricant degradation in service; however, any condemning limits must be empirically established.
SCOPE
1.1 This test method covers the determination of basic constituents in petroleum products by titration with perchloric acid in glacial acetic acid.  
1.2 Procedures A and B use different titration solvent volumes and sample weights.  
Note 1: A round robin on a series of new and used oils and additive concentrates has shown that the two procedures give statistically equivalent results.  
1.3 Appendix X2 provides the use of an alternative solvent system which eliminates the use of chlorobenzene in this test method. The use of the alternative solvent gives statistically equivalent results; however, the precision is worse. Paragraph X2.5.5 provides guidance when comparing results using the two different solvents.  
1.4 The constituents that may be considered to have basic characteristics include organic and inorganic bases, amino compounds, salts of weak acids (soaps), basic salts of polyacidic bases, and salts of heavy metals.  
Note 2: This test method is applicable to both fresh oils and used oils as described in Sections 16, 17, and 19 and Appendix X1.  
1.5 This test method can be used to determine base number >300 mg KOH/g. However, the precision statement in Section 19 has been obtained only on base number ≤300 mg KOH/g.  
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.7 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. For specific warning statements, see Section 7, Section 10, and X2.2.

General Information

• Status: Historical
• Publication Date: 30-Nov-2015
• ICS: 75.080 - Petroleum products in general
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.06 - Analysis of Liquid Fuels and Lubricants

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: D2896 − 15
Standard Test Method for
Base Number of Petroleum Products by Potentiometric
1
Perchloric Acid Titration
This standard is issued under the fixed designation D2896; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* bility of regulatory limitations prior to use. For specific
warning statements, see Section 7, Section 10, and X2.2.
1.1 This test method covers the determination of basic
constituents in petroleum products by titration with perchloric
2. Referenced Documents
acid in glacial acetic acid.
2
2.1 ASTM Standards:
1.2 Procedures A and B use different titration solvent
D1193Specification for Reagent Water
volumes and sample weights.
3. Terminology
NOTE 1—A round robin on a series of new and used oils and additive
concentrates has shown that the two procedures give statistically equiva-
3.1 Definitions:
lent results.
3.1.1 base number—the quantity of a specified acid, ex-
1.3 Appendix X2 provides the use of an alternative solvent
pressed in terms of the equivalent number of milligrams of
system which eliminates the use of chlorobenzene in this test
potassium hydroxide per gram of sample, required to titrate a
method. The use of the alternative solvent gives statistically
sample in a specified solvent to a specified endpoint using a
equivalent results; however, the precision is worse. Paragraph
specified detection system.
X2.5.5 provides guidance when comparing results using the
two different solvents.
4. Summary of Test Method
1.4 The constituents that may be considered to have basic
4.1 The sample is dissolved in an essentially anhydrous
characteristics include organic and inorganic bases, amino
mixture of chlorobenzene and glacial acetic acid and titrated
compounds, salts of weak acids (soaps), basic salts of poly-
with a solution of perchloric acid in glacial acetic acid using
acidic bases, and salts of heavy metals.
potentiometric titrimeter. A glass indicating electrode and a
reference electrode are used, the latter being connected with
NOTE 2—This test method is applicable to both fresh oils and used oils
as described in Sections 16, 17, and 19 and Appendix X1.
the sample solution by means of a salt bridge. The meter
readings are plotted against the respective volumes of titrating
1.5 This test method can be used to determine base number
solution, and the end point is taken at the inflection in the
>300mg KOH/g. However, the precision statement in Section
resulting curve.
19 has been obtained only on base number ≤300mg KOH/g.
4.2 ProcedureAuses120mLoftitrationsolvent.Procedure
1.6 The values stated in SI units are to be regarded as
B uses 60mL of titration solvent. In addition, the two
standard. No other units of measurement are included in this
proceduresusedifferentequationsforthecalculationofappro-
standard.
priate sample weights. Since many portions of the test method
1.7 This standard does not purport to address all of the
are identical for ProceduresAand B, only the unique sections
safety concerns, if any, associated with its use. It is the
will be described separately for the two versions of the test
responsibility of the user of this standard to establish appro-
method.
priate safety and health practices and determine the applica-
4.3 Occasionally certain used oils give no inflection in the
forward titration mode, in which case a back titration modifi-
1
This test method is under the jurisdiction of ASTM Committee D02 on
cation with sodium acetate titrant is employed.
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.06 on Analysis of Liquid Fuels and Lubricants.
Current edition approved Dec. 1, 2015. Published February 2016. Originally
2
approved in 1970. Last previous edition approved in 2011 as D2896–11. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D2896-15. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
This test method has been approved by the sponsoring committees and accepted Standards volume information, refer to the standard’s Document Summary page on
by the cooperating societies in accordance with established procedures. 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
1

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D2896 − 15
5. Significance and Use tee onAnalytical Reagents of theAmerican
...

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: D2896 − 11 D2896 − 15
Standard Test Method for
Base Number of Petroleum Products by Potentiometric
1
Perchloric Acid Titration
This standard is issued under the fixed designation D2896; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This test method covers the determination of basic constituents in petroleum products by titration with perchloric acid in
glacial acetic acid.
1.2 Procedures A and B use different titration solvent volumes and sample weights.
NOTE 1—A round robin on a series of new and used oils and additive concentrates has shown that the two procedures give statistically equivalent
results.
1.3 Appendix X2 provides the use of an alternative solvent system which eliminates the use of chlorobenzene in this test
method. The use of the alternative solvent gives statistically equivalent results; however, the precision is worse. Paragraph X2.5.5
provides guidance when comparing results using the two different solvents.
1.4 The constituents that may be considered to have basic characteristics include organic and inorganic bases, amino
compounds, salts of weak acids (soaps), basic salts of polyacidic bases, and salts of heavy metals.
NOTE 2—This test method is applicable to both fresh oils and used oils as described in Sections 16, 17, and 19 and Appendix X1.
1.5 This test method can be used to determine base number >300 mg >300 mg KOH/g. However, the precision statement in
Section 19 has been obtained only on base number ≤300 mg ≤300 mg KOH/g.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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. For specific warning statements, see Section 7, Section 10, and X2.2.
2. Referenced Documents
2
2.1 ASTM Standards:
D1193 Specification for Reagent Water
3. Terminology
3.1 Definitions:
3.1.1 base number—the quantity of a specified acid, expressed in terms of the equivalent number of milligrams of potassium
hydroxide per gram of sample, required to titrate a sample in a specified solvent to a specified endpoint using a specified detection
system.
4. Summary of Test Method
4.1 The sample is dissolved in an essentially anhydrous mixture of chlorobenzene and glacial acetic acid and titrated with a
solution of perchloric acid in glacial acetic acid using potentiometric titrimeter. A glass indicating electrode and a reference
1
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.06 on Analysis of Liquid Fuels and Lubricants.
Current edition approved May 15, 2011Dec. 1, 2015. Published July 2011February 2016. Originally approved in 1970. Last previous edition approved in 20072011 as
D2896D2896 – 11.–07a. DOI: 10.1520/D2896-11.10.1520/D2896-15.
This test method has been approved by the sponsoring committees and accepted by the cooperating societies in accordance with established procedures.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. 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
1

---------------------- Page: 1 ----------------------
D2896 − 15
electrode are used, the latter being connected with the sample solution by means of a salt bridge. The meter readings are plotted
against the respective volumes of titrating solution, and the end point is taken at the inflection in the resulting curve.
4.2 Procedure A uses 120 mL 120 mL of titration solvent. Procedure B uses 60 mL 60 mL of titration solvent. In addition, the
two procedures use different equations for the calculation of appropriate sample weights. Since many
...