Sequential extraction procedure for speciation of inorganic cadmium in emissions and working areas

A sequential extraction procedure for separating and concentrating soluble Cd(II) salts, CdO, Cd(0), CdS, CdSe and cadmium-aluminosilicates, has been developed for the cadmium speciation in samples such as particulate matter in emissions and working areas. The proposed procedure has been tested first on synthetic samples prepared in a laboratory with the different cadmium salts, then also in the presence of atmospherical particulate matter sampled in a laboratory of the Department of Analytical Chemistry, previously checked for the absence of cadmium. Finally the speciation was tested on particulate matter collected near the emission of a power plant fed by coal, after emission's treatment by electrostatic precipitator: matrix spiking and recovery analyses have been evaluated and the repeatability of the cadmium speciation was assessed by performing multiple analyses of the spiked samples. Quantitative determinations have been made by FAAS and GFAAS through the standard additions method.