Drugs. Differential pulse polarography of cacodylate injections

A method was developed for the analysis of cacodylate injections, using differential pulse polarography for measuring As(III). The cacodylate molecule is decomposed to As(V) by heating with Mg(NO3)2.6H20; As(V) is then chemically reduced to As(III) and polarographed in 1M HCl supporting electrolyte. The method of standard addition is used for quantitation. Recoveries based on the analysis of synthetic cacodylic acid solutions containing approximately 9 mg arsenic/ml ranged from 99.1 to 101.7%.