ASTM D1767-89(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: D1767 − 89 (Reapproved 2017)
Standard Test Method for
Ethylene Diamine Tetraacetate (EDTA) in Soaps or Synthetic
Detergents
This standard is issued under the fixed designation D1767; 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 used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
1.1 This test method covers the determination of ethylene
accuracy of the determination.
diamine tetraacetate (EDTA) in soaps and synthetic detergents.
Throughout this test method EDTA represents the hydrated 3.2 Unless otherwise indicated, references to water shall be
disodium salt containing 2 moles of H O. In the chemical understood to mean reagent water conforming to Specification
literature this is frequently abbreviated to Na H Y ·2H O. D1193.
2 2 4 2
1.2 The values stated in SI units are to be regarded as
4. Reagents
standard. No other units of measurement are included in this
4.1 Copper Sulfate Solution (1 mL = 0.0037 g EDTA diso-
standard.
dium salt)—Dissolve 2.497 g of copper sulfate (CuSO ·5H O)
4 2
1.3 This standard does not purport to address all of the
in water and dilute to 1 L. The actual EDTAequivalent should
safety concerns, if any, associated with its use. It is the
be determined by the titration of a known weight of EDTA
responsibility of the user of this standard to establish appro-
disodium salt.
priate safety and health practices and determine the applica-
4.2 PAN Indicator Solution—Dissolve 0.1 g of 1-(2
bility of regulatory limitations prior to use. Material Safety
pyridylazo)-2-naphathol in 100 mL of methyl alcohol.
Data Sheets are available for reagents and materials. Review
them for hazards prior to usage.
5. Procedure
2. Referenced Documents
5.1 Weigh to the nearest 0.001ga3to5-g portion of the
sample estimated to contain 1 % of EDTA disodium salt. Vary
2.1 ASTM Standards:
the amount of the sample used depending upon the actual
D1193 Specification for Reagent Water
amount of EDTA present. Weigh into a 250-mL beaker, dilute
to approximately 75 mL with water, and adjust the pH to
3. Purity of Reagents
approximately 5.0 by the addition of acetic acid (Note 1).Add
3.1 Purity of Reagents—Reagent grade chemicals shall be
4 drops of the PAN indicator solution. Titrate the sample with
used in all tests. Unless otherwise indicated, it is intended that
CuSO solution to a transition in color from yellow to red.
all reagents shall conform to the specifications of the Commit-
tee onAnalytical Reagents of theAmerican Chemical Society, NOTE 1—Removal of soap fatty acids by filtration through a wet filter
paper prior to titration will sharpen the end point.
where such specifications are available. Other grades may be
6. Calculation
This test method is under the jurisdiction of ASTM Committee D12 on Soaps
6.1 Calculate the percentage of EDTA disodium salt in the
and Other Detergents and is the direct responsibility
...