ASTM D4711-89(2017)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4711 − 89 (Reapproved 2017)
Standard Test Method for
Sulfonic and Sulfuric Acids in Alkylbenzene Sulfonic Acids
This standard is issued under the fixed designation D4711; 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 lated from the titrant volume between the two inflections,
which is equivalent to the amount of base required for
1.1 This test method is applicable to the determination of
neutralization of the bisulfate anion.
sulfonic and sulfuric acids in branched and linear alkylbenzene
sulfonic acids used as intermediates in synthetic detergents.
4. Significance and Use
1.2 The values stated in SI units are to be regarded as
4.1 Alkylbenzenesulfonicacidsareimportantintermediates
standard. No other units of measurement are included in this
in the synthetic detergent industry and are defined under “alkyl
standard.
benzene sulfonate” in Terminology D459. This test method is
1.3 This standard does not purport to address all of the
suitable for the rapid monitoring of the sulfonic and sulfuric
safety concerns, if any, associated with its use. It is the
acid levels, both of which have a vital bearing on final product
responsibility of the user of this standard to establish appro-
performance and appearance.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Material Safety
5. Interferences
Data Sheets are available for reagents and materials. Review
5.1 Strong acids, like nitric and hydrochloric, interfere, as
them for hazards prior to usage.
do weak acids, such as carboxylic acids. Small amounts of
2. Referenced Documents
water originally present in the sample do not interfere in the
determination. However, if as much as 5 % of water is present
2.1 ASTM Standards:
in the total solution (solvent plus sample), the end point
D459 Terminology Relating to Soaps and Other Detergents
becomes less sharp.
E180 Practice for Determining the Precision of ASTM
Methods for Analysis and Testing of Industrial and Spe-
6. Apparatus
cialty Chemicals (Withdrawn 2009)
6.1 Potentiometric Titrator, and combination calomel ref-
3. Summary of Test Method
erence electrode.
3.1 A methanolic solution of the sample is titrated with
6.2 Buret Assembly, having a 20 mL buret.
cyclohexylamine in methanol to yield a potentiometric curve.
6.3 Beaker, 180 mL tall form.
(See Fig. 1.)The first inflection represents the neutralization of
strong acids, such as sulfonics and alkylsulfurics, and the first
6.4 Volumetric Flask, Class A, 500 mL.
hydrogen of sulfuric acid. The second inflection represents the
6.5 Magnetic Stirrer, and stirring bar.
neutralization of the second hydrogen of sulfuric acid. The
amount of sulfonic acid is calculated based on the titrant
7. Reagents and Materials
volume of the first inflection minus that between the two
7.1 Methanol, anhydrous,
inflections. The amount of sulfuric acid meanwhile is calcu-
7.2 Cyclohexylamine (0.10 N)—Dissolve 10 g of reagent
cyclohexylamine in 1000 mL of anhydrous methanol. Stan-
This test method is under the jurisdiction of ASTM Committee D12 on Soaps
and Other Detergents and is the direct responsibility of Subcommittee D12.12 on dardize against sulfamic acid as described in Section 8.
Analysis and Specifications of Soaps, Synthetics, Detergents and their Components.
7.3 Sulfamic Acid, acidimetric standard.
Current edition approved Jan. 1, 2017. Published February 2017. Originally
approvedin1987.Lastpreviouseditionapprovedin2009asD4711-89(2009).DOI:
10.1520/D4711-89R17.
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 Metrohm A436, or its equivalent, has been found suitable for this purpose.
Standards volume information, refer to the standard’s Document Summary page on Available from Brinkman Instruments.
the ASTM website. J.T. Baker No. 4898, or its equivalent, has been found suitable for this purpose.
The last approved version of this historical standard is referenced on Available from Sargent-Welch Scientific Co., 7300 Linder Ave., PO Box 1026,
www.astm.org. Skokie, IL 60077.
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D4711 − 89 (2017)
Grams sample 5 1.35 meq/meq/g acidity expected (2)
NOTE 1—Most detergent range alkylbenzene sulfonic acids have a total
acidity of about 3.35 meq/g meaning that the sample weight should be
about 0.35 to 0.45 g. This yields a total titer of about 12 to 15 mL of 0.10
N cyclohexylamine and a difference of about 0.45 to 0.68 mLbetween the
two breaks for a sample containing about 1.25 % sulfuric acid.
9.2 Add a magnetic stirring bar, 100 mL of anhydrous
methanol, and stir with a magnetic stirrer until dissolved.
9.3 Titrate potentiometrically on the automatic titrator using
the combination electrode until a curve yielding two breaks is
obtained. (See Fig. 1.)
9.4 Record the vol
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