Silver Diethyldithiocarbamate - ACS Reagent Chemicals (ACS

Feb 28, 2017 - Typical appearance. greenish-yellow solid. Applications. determination of arsenic. Change in state (approximate). melting point, 175 °...
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Monograph pubs.acs.org/doi/book/10.1021/acsreagents

Silver Diethyldithiocarbamate Part 4, Monographs for Reagent Chemicals: General Descriptions, Specifications, and Tests eISBN: 9780841230460 Tom Tyner Chair, ACS Committee on Analytical Reagents James Francis Secretary, ACS Committee on Analytical Reagents

ABSTRACT This monograph for Silver Diethyldithiocarbamate provides, in addition to common physical constants, a general description including typical appearance, applications, change in state (approximate), and aqueous solubility. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Solubility in Pyridine and Suitability for Determination of Arsenic.

(C2H5)2NCS2Ag

Formula Wt 256.13

CAS No. 1470-61-7

Note: To enhance stability, storage below 8 °C is recommended.

GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .

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greenish-yellow solid determination of arsenic melting point, 175 °C insoluble

SPECIFICATIONS Solubility in pyridine . . . . . . . . . . . . . . . . . . Passes test Suitability for determination of arsenic . . . . . . Passes test

© 2017 American Chemical Society

A

DOI:10.1021/acsreagents.4321 ACS Reagent Chemicals, Part 4

ACS Reagent Chemicals

Monograph

pubs.acs.org/doi/book/10.1021/acsreagents

TESTS Solubility in Pyridine Transfer 1 g of sample to a 200 mL volumetric flask, and dilute to the mark with freshly distilled pyridine. The solution should be clear, bright yellow, and dissolution should be complete. (Save this solution for the suitability for determination of arsenic test.)

Suitability for Determination of Arsenic Transfer 0.002 mg of arsenic ion (As) to an arsine generator flask and dilute with water to 35 mL. (For a description of the apparatus used in this test, see [Part 2: Colorimetry and Turbidimetry; Arsenic; Apparatus].) Add 20 mL of dilute sulfuric acid (1:4), 2 mL of 16.5% potassium iodide reagent solution, and 0.5 mL of 40% stannous chloride dihydrate reagent solution in concentrated hydrochloric acid. Mix, and allow to stand for 30 min at room temperature. Pack the scrubber tube loosely with two pledgets of lead acetate cotton. Place 3.1 mL of sample solution, retained from the solubility in pyridine test, in the absorber tube. Quickly add 3.0 g of granulated (No. 20 mesh) zinc to the arsine generator flask, and immediately connect the flask to the scrubber–absorber assembly. Allow the evolution of hydrogen to proceed at room temperature for 45 min, swirling the solution every 10 min. Disconnect the absorber tube, and determine the absorbance of the solution in a 1.00 cm cell at 525 nm against a fresh portion of the sample solution in a similar matched cell set at zero absorbance as the reference liquid. The absorbance should not be less than 0.10.

© 2017 American Chemical Society

B

DOI:10.1021/acsreagents.4321 ACS Reagent Chemicals, Part 4