Astm D 3873 – 01 pdf free download

Standard Test Method for
Valency State of the Arsenic Component of Ammoniacal
Copper Zinc Arsenate Solutions1

This standard is issued under the fixed designation D 3873; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of the last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope

1.1 This test method is intended for testing batches of
concentrated ammoniacal copper zinc arsenate (ACZA) solution, prepared by air-oxidation of trivalent arsenic. The test
method provides a means of confirming that oxidation has been
completed and that at least 99.5 % of the arsenic has been
oxidized. The sample for testing should contain 100 6 20 mg
of potential As2 O5. An A200-mL aliquot of a concentrate containing 8 to 12 % of preservative oxides is suitable.

1.2 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.

2. Referenced Documents

2.1 ASTM Standards:
D 1193 Specification for Reagent Water2
D 1325 Specification for ACA and ACZA Solutions3

3. Summary of Test Method

3.1 Twenty milliliters of the tartaric acid solution is added to a
250 mL Erlenmeyer flask, then 2 mL of the ACZA concentrate
is added. The resulting solution should be light blue-green.
Next, 20 mL of sodium bicarbonate solution is added. The
resulting solution will then be light blue. Next, 2 ml of the
starch indicator is added. To this solution, one drop of iodine
solution is added by means of a buret. If the concentrate
solution turns a dark blue and remains, it means the arsenic
oxidation by aeration has been completed.