Method of analyzing gold electroplating solutions for arsenic(III)

A method of analyzing for As(III) as AsO2-1 ion in an Au(I) containing electroplating solution. The concentration of As(III) in the electroplating solution is maintained high enough to avoid formation of "burnt Au" oxides but low enough to avoid bond failures. A sample of the electroplating solution is withdrawn and added to a buffered solution, for example an acetate-ethylene diamine tetraacetic acid (EDTA) buffered solution. A complexing agent for Au(I) ion is added to the buffered solution. This can be an alkali metal cyanide. Next ammonium pyrrolidine dithiocarbamate is added as a complexing agent for the AsO2-1 ion. The ammonium pyrrolidine dithiocarbamate-AsO2-1 ion is extracted, for example with methyl isobutyl ketone (MIBK). The extract is analyzed for As(III) by atomic absorption, as electrothermal atomic absorption spectrometry.