ASTM D4711-89 (2017) PDF

Full title and description

ASTM D4711-89(2017) — Standard Test Method for Sulfonic and Sulfuric Acids in Alkylbenzene Sulfonic Acids. This short test method describes a potentiometric titration procedure for rapid determination of sulfonic and sulfuric acid contents in branched and linear alkylbenzene sulfonic acids, which are important intermediates in the synthetic detergent industry.

Abstract

This standard specifies dissolving a weighed sample in anhydrous methanol and titrating with a standardized cyclohexylamine solution while monitoring the potentiometric curve. Two inflection points are used: the first corresponds to neutralization of strong acids (sulfonic and alkylsulfuric acids and the first hydrogen of sulfuric acid) and the second to the second hydrogen of sulfuric acid. The sulfonic-acid content is calculated from the titrant volume to the first break minus the volume between the two breaks, and sulfuric acid content from the second break. SI units are specified and safety/data-sheet review is recommended.

General information

• Status: Withdrawn / historical (2017 edition) and subsequently revised in a later ASTM document cycle; the 2017 edition is recorded as withdrawn in secondary catalog listings and a 2025 revision entry is shown in standards catalog metadata.
• Publication date: 01 January 2017 (approved Jan 1, 2017; published Feb 2017 in ASTM records).
• Publisher: ASTM International.
• ICS / categories: 71.080.40 (Organic acids / related analytical methods).
• Edition / version: Designated D4711-89(2017) (historical designation appears as D4711-89R17 in some catalog records).
• Number of pages: 3 pages (concise method sheet).

Scope

The method applies to determination of sulfonic and sulfuric acids in branched and linear alkylbenzene sulfonic acids used as intermediates in synthetic detergents. It provides a rapid laboratory procedure for routine monitoring of these acidic constituents and states that values are to be reported in SI units; it also notes that the standard does not address all safety concerns and that users must observe appropriate safety and regulatory measures.

Key topics and requirements

• Analyte: sulfonic acids and sulfuric acids present in alkylbenzene sulfonic-acid samples.
• Sample preparation: dissolution in anhydrous methanol.
• Titrant and concentration: standardized 0.10 N cyclohexylamine in methanol (method describes preparation and standardization).
• Measurement technique: potentiometric titration using a combination electrode and automatic or manual titrator to detect two inflection points on the titration curve.
• Calculations: sulfonic-acid amount derived from first inflection minus volume between inflections; sulfuric-acid from second inflection (method details formulae and expected titration ranges).
• Units and reporting: SI units required by the standard; include appropriate significant figures and reagent safety documentation.

Typical use and users

Quality control and analytical laboratories in the detergent and surfactant manufacturing sector, process chemists, R&D chemists developing alkylbenzene sulfonates, and contract testing labs performing routine compositional checks. The method is used for rapid monitoring of intermediates where sulfonic and sulfuric acid levels affect product performance and appearance.

Related standards

Referenced terminology and related methods within ASTM Committee D12 (Soaps and Other Detergents) are relevant; the standard references Terminology D459 for alkylbenzene sulfonate definitions and sits alongside other ASTM analytical practices for surfactants and organic-acid determinations. For current or replacement methods, consult the ASTM D12 committee outputs and the most recent D4711 revision history.

Keywords

alkylbenzene sulfonic acid, sulfonic acid, sulfuric acid, potentiometric titration, cyclohexylamine titrant, detergent intermediates, ASTM D4711, surfactant analysis, quantitative titration.

FAQ

Q: What is this standard?

A: It is ASTM D4711-89(2017), a short test method describing potentiometric titration for determining sulfonic and sulfuric acids in alkylbenzene sulfonic acids.

Q: What does it cover?

A: The method covers sample dissolution in anhydrous methanol, titration with 0.10 N cyclohexylamine, detection of two potentiometric inflections, and calculation of sulfonic- and sulfuric-acid contents; SI units are required and safety considerations are noted.

Q: Who typically uses it?

A: Analytical and QC laboratories in detergent/surfactant manufacture, R&D chemists, and contract testing services that monitor acid content in alkylbenzene sulfonate intermediates.

Q: Is it current or superseded?

A: The 2017 edition is recorded in standards catalogs as a historical/withdrawn item; catalog metadata indicates a later revision entry in 2025. Users should check ASTM committee D12 publications or the latest ASTM catalog records to confirm the currently active document before relying on the 2017 text.

Q: Is it part of a series?

A: It is maintained under ASTM Committee D12 (Soaps and Other Detergents) and is part of the family of analytical methods and terminologies for soap, detergent and surfactant analysis (references to Terminology D459 and other D12 procedures are typical).

Q: What are the key keywords?

A: alkylbenzene sulfonic acid; sulfonic acid; sulfuric acid; potentiometric titration; cyclohexylamine; detergent intermediates; ASTM D4711.