This test method covers the determination of ethylene diamine tetraacetate (EDTA) in soaps and synthetic detergents. Throughout this test method EDTA represents the hydrated disodium salt containing 2 moles of H₂O. In the chemical literature this is frequently abbreviated to Na₂H₂Y4·2H₂O. Reagents to be used in the EDTA content determination include copper sulfate solution and PAN indicator solution. The procedure in EDTA determination is described as follows: A portion of the sample estimated to contain 1 % of EDTA disodium salt shall be weighed. The amount of the sample used depending upon the actual amount of EDTA present shall be varied. Then the sample shall be weighed into a 250-mL beaker, diluted to a certain volume with water, and adjusted the pH to approximately 5.0 by the addition of acetic acid. Four drops of the PAN indicator solution shall be added. The sample with CuSO4 solution shall be titrated until a transition in color from yellow to red occurs. Afterwards, the percentage of EDTA disodium salt in the sample shall be calculated.

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1. Scope

1.1 This test method covers the determination of ethylene diamine tetraacetate (EDTA) in soaps and synthetic detergents. Throughout this test method EDTA represents the hydrated disodium salt containing 2 moles of H₂O. In the chemical literature this is frequently abbreviated to Na₂H₂Y₄ · 2H₂O.

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.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D1193 Specification for Reagent Water

Keywords

copper sulfate titration; EDTA; ethylene diamine tetraacetate; Detergent materials/systems--synthetic; EDTA method; Ethylenediamine tetraacetic acid (Na4EDTA); Soap;

ICS Code

ICS Number Code 71.100.40 (Surface active agents)

Citing ASTM Standards

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