ASTM D2023-89(2016)

• Abstract:

  SIGNIFICANCE AND USE; 4.1 This test method is of use to anyone engaged in compositional analysis of detergent formulations. This would include formulators, and analysts employed by companies that manufacture the components usually included in such formulations.; SCOPE; 1.1 This test method covers the analysis for the apparent sodium toluene sulfonate (NaTS) content of detergents. ; 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. ; 1.3 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. Material Safety Data sheets are available for reagents and materials. Review them for hazards prior to usage.

• Status: Published
• Publication Date: 30-Jun-2016
• ICS: 71.100.40 - Surface active agents
• Technical Committee: D12 - Soaps and Other Detergents
• Drafting Committee: D12.12 - Analysis and Specifications of Soaps, Synthetics, Detergents and their Components

• Replaces: ASTM D2023-89(2009) - Standard Test Method of Analysis for Sodium Toluene Sulfonate in Detergents
• Effective Date: 01-Jul-2016
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

Overview

ASTM D2023-89(2016) is the internationally recognized Standard Test Method of Analysis for Sodium Toluene Sulfonate in Detergents. Developed by ASTM International, this standard outlines the procedure for determining the content of apparent sodium toluene sulfonate (NaTS) in detergent formulations. Accurate analysis of NaTS is crucial for both detergent manufacturers and formulators to ensure product quality, regulatory compliance, and effectiveness of their formulations.

This standard is grounded in established principles for global standardization, assuring reliability and consistency across laboratories and industries. The method relies on ultraviolet absorption after separation of interfering substances, supporting precise and reproducible results.

Key Topics

• Sample Preparation and Apparatus:

  • Use of glass-only apparatus to prevent contamination.
  • Utilization of analytical balances and spectrophotometric equipment suitable for UV measurement in the 230–300 nm range.

• Interference and Specificity:

  • Awareness that low molecular weight substituted benzene sulfonates and benzene sulfonate (NaBS) may interfere in the analysis.
  • Importance of thorough checks using absorption curves if contamination is suspected.

• Reagents and Safety:

  • Emphasis on reagent-grade chemicals and high-purity water as per ASTM D1193.
  • Specific mention of ethyl ether and hydrochloric acid, underlining the need for adherence to designated safety practices and consultation of Material Safety Data Sheets (MSDS).

• Method Precision:

  • Within-laboratory precision: 0.085%
  • Between-laboratory precision: 0.200%
  • These values confirm the robustness and repeatability of the test at typical use concentrations.

• Significance and Use:

  • The method is intended for use by detergent manufacturers, component suppliers, and quality control laboratories.

Applications

• Compositional Analysis:

  • Ensures the correct formulation of detergents, especially for manufacturers focused on performance optimization and regulatory compliance.
  • Used for quality assurance during production to verify NaTS levels, a key hydrotrope in many detergent products.

• Research and Development:

  • Useful for formulators developing new detergent blends or studying the role of hydrotropes like sodium toluene sulfonate.

• Regulatory Compliance:

  • Supports organizations in meeting international standards and customer specifications.

• Supply Chain Verification:

  • Enables suppliers of detergent components to provide certified ingredient analysis to clients.

• Cross-laboratory Standardization:

  • Facilitates consistent analytical results across multiple laboratories, supporting contract manufacturing and multi-site quality assurance programs.

Related Standards

To ensure accurate and reliable analysis, reference to the following related standards is recommended:

• ASTM D1193 - Specification for Reagent Water: Defines water purity requirements, essential for analytical reproducibility.
• American Chemical Society Reagent Specifications: Detailed requirements for the chemical purity of reagents used in compositional testing.
• Other Detergent and Surfactant Standards: Including standards for methods of analysis, performance testing, and raw material specifications relevant to detergents.

Researchers and analysts engaged in compositional analysis of detergents should familiarize themselves with these and other applicable ASTM standards to maintain best practices and ensure compliance with industry expectations.

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Keywords: sodium toluene sulfonate analysis, NaTS in detergents, ASTM D2023, ultraviolet absorption method, detergent composition analysis, hydrotropes, quality control, laboratory standards

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: D2023 − 89 (Reapproved 2016)
Standard Test Method of
Analysis for Sodium Toluene Sulfonate in Detergents
This standard is issued under the fixed designation D2023; 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 5. Interferences
1.1 This test method covers the analysis for the apparent 5.1 Any low molecular weight substituted benzene sul-
sodium toluene sulfonate (NaTS) content of detergents. fonate or benzene sulfonate (NaBS) itself will interfere and
give an apparent toluene sulfonate figure. Since the method is
1.2 The values stated in SI units are to be regarded as
standardized using p-toluene sulfonate, o-sulfonate will not be
standard. No other units of measurement are included in this
assayed correctly. When contamination is suspected, it should
standard.
be checked by running a complete absorption curve and
1.3 This standard does not purport to address all of the
comparing with known samples.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
6. Apparatus
priate safety and health practices and determine the applica-
NOTE 1—Absolute cleanliness of apparatus is essential. Use glass
apparatus only. Contact with rubber, cork, or hands will introduce
bility of regulatory limitations prior to use. Material Safety
absorbance errors.
Data sheets are available for reagents and materials. Review
6.1 Separatory Funnels, 500-mL capacity, glass-stoppered,
them for hazards prior to usage.
pear-shaped.
2. Referenced Documents
6.2 Balance, analytical.
2.1 ASTM Standards:
6.3 Spectrophotometer (Note 2), with necessary ultraviolet
D1193 Specification for Reagent Water
accessories for working in the range from 230 to 300 nm.
These include 1.00 and 5.00-cm absorption cells with quartz
3. Summary of Test Method
windows.
3.1 This test method is based on the separation of the low
NOTE 2—Details of the test method as written are based on the use of
molecular weight sulfonate from interfering higher molecular
the Beckman DU or Cary recording spectrophotometers. Equivalent
weight sulfonates and determination by ultraviolet absorption.
spectrophotometers also may be used, provided suitable modifications can
be made in the details of the method.
The higher molecular weight sulfonates are extracted as
sulfonic acids in a hydrochloric acid solution using ethyl ether
7. Reagents
as the solvent.
7.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
4. Significance and Use
all reagents shall conform to the specifications of the Commit-
4.1 This test method is of use to anyone engaged in
tee onAnalytical Reagents of theAmerican Chemical Society,
compositional analysis of detergent formulations. This would
where such specifications are available. Other grades may be
include formulators, and analysts employed by companies that
used, provided it is first ascertained that the reagent is of
manufacture the components usually included in such formu-
sufficiently high purity to permit its use without lessening the
lations.
accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references
to water shall be understood to mean reagent water conforming
This test method is under the jurisdiction of ASTM Committee D12 on Soaps
to Specification D1193.
and Other Detergents and is the direct responsibility of Subcommittee D12.12 on
Analysis and Specifications of Soaps, Synthetics, Detergents and their Components.
Current edition approved July 1, 2016. Published August 2016. Originally
approved in 1962 as D2023 – 62 T. Last previous edition approved in 2009 as Reagent Chemicals, American Chemical Society Specifications, American
D2023 – 89(2009). DOI: 10.1520/D2023-89R16. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
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D2023 − 89 (2016)
7.3 Ethyl Ether. 10. Procedure
7.4 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro- 10.1 Weigh 10.00 6 0.01 g of the sample of synthetic
chloric acid (HCl). detergent to be analyzed and dissolve in about 75 mL of hot
water. Transfer to a 500-mL glass-stoppered, pear-shaped,
7.5 Hydrochloric Acid (1+3)—Mix 1 volume of concen-
separatory funnel; add 10.0 g of Na SO and 40 mL of HCl.
2 4
trated HCl with 3 volumes of water.
Swirl to dissolve and cool to room temperature.
7.6 p-Toluenesulfonic Acid Sodium Salt (NaTS) —Dry for
10.2 Extract twice with 100-mL portions of ethyl ether,
24 h at 105°C and store in a desiccator. Use for preparat
...