ASTM D2942-02(2023) PDF

Overview

ASTM D2942-02(2023): Standard Test Method for Total Acid Acceptance of Halogenated Organic Solvents (Nonreflux Methods) provides an industry-accepted procedure for determining total acid acceptance in halogenated organic solvents. Acid acceptance is a critical quality factor for these solvents, as loss of stabilizers can result in acid formation, which may lead to equipment corrosion and affect solvent performance. This method is relied upon by both producers and users of halogenated solvents to verify compliance with product specifications and monitor in-use solvent condition.

Key Topics

• Total Acid Acceptance Measurement The standard outlines procedures to determine the total acid acceptance of a solvent, quantifying the combined stabilizing effect of both amine-type (alkaline) and neutral-type (e.g., epoxide) additives.

• Importance of Stabilizer Content Stabilizers help inhibit acid formation in halogenated organic solvents. Depleted stabilizer levels can turn solvents acidic, posing risks such as corrosion of process and storage equipment.

• Test Methods

  • Method A (Titration): Measures total acid acceptance using a titration technique with hydrochloric acid in isopropyl alcohol followed by back-titration with sodium hydroxide.
  • Method B (Instrumental): Determines acid acceptor content via validated instrumental analysis (e.g., gas chromatography), and calculates acid acceptance accordingly. Method selection should consider the type of solvent system and potential interferences.

• Separation of Stabilizer Types By using complementary methods (such as ASTM D2106 for amine stabilizers), the contribution of individual stabilizer types to total acid acceptance can be distinguished.

• Precision and Validity

  • Precision limits for the titration method are established at 0.01% (weight % as NaOH).
  • Instrumental methods should be validated for accuracy and potential interferences.

Applications

• Solvent Quality Control Enables manufacturers and users to ensure halogenated organic solvents meet acid acceptance specifications, an essential quality parameter for safe handling and effective application.

• Process and Equipment Protection Monitoring acid acceptance prevents the use of acidic, destabilized solvents that could corrode metal tanks, piping, and process equipment.

• In-Use Solvent Monitoring Facilities using halogenated solvents in cleaning or degreasing operations can track stabilizer depletion over time, proactively managing solvent replacement to minimize risks.

• Specification Compliance The method supports commercial and regulatory compliance for the chemical manufacturing, electronics, aerospace, and metalworking industries where halogenated solvents are common.

Related Standards

• ASTM D2106 - Test Methods for Determination of Amine Acid Acceptance (Alkalinity) of Halogenated Organic Solvents. Used to quantify amine-type stabilizer content, facilitating calculation of neutral-type acceptance.
• ASTM D1193 - Specification for Reagent Water. Specifies water quality for chemical analysis.
• ASTM E200 - Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis. Ensures consistency in titration reagents.

Keywords: ASTM D2942, acid acceptance, halogenated organic solvents, stabilizer analysis, solvent quality control, corrosion prevention, solvent monitoring, chemical standards

For further information, refer to ASTM International at www.astm.org for official documentation.