Photometric Determination of Arsenic in Copper and Copper-Base Alloys

Chemical speciation of elements in stack-collected, respirable-size, coal fly ash

“…An attempt as made to verify the oxidation state of the arsenic by selective arsine generation with NaBH4, first at a slightly basic pH and then in 1 M HC1 (17). The arsine was passed through cotton dampened with lead acetate, absorbed into 1 mM I2 solution, and determined by the heterpoly blue method (18). The results were not quantitative because recovery of total arsenic by this procedure was incomplete, i.e., 50-70%.…”

Determination of Arsenic in Biological Materials

“…The heteropoly blue compound formed by condensation of arsenate and molybdate ions to form molybdiarsenic acid which is reduced by hydrazine sulfate to the stable blue compound has been used for many years in the determination of arsenic [4][5][6][7][8][9][10][11][12]. Early workers (8, 7, 9, 11, 13) measured the transmittancy at 610 to 725 µ wave length, probably because of the limited range of their photoelectric colorimeters, but Sultzaberger (13) using a Beckman spectrophotometer found that maximum absorption for tlie arsenic complex is in the infrared at about 840 µ.…”

Light Absorption Spectrometry

“…Molybdogermanic acid, reduced to molybdenum blue by hydroquinone, is the basis for a method for germanium in silicates (40). Similarly, molybdoarsenic acid reduced to molybdenum blue by hydrazine sulfate serves for copper in copper-base alloys (24). The use of tungstosilicic acid in a method for ascorbic acid (8) illustrates the application of heteropoly acids for determining certain reducing substances through the formation of heteropoly blues.…”