Generation of atomic and molecular cadmium species from aqueous media.

Generation of atomic and molecular species of cadmium following reaction of acidified sample with sodium tetrahydroborate reductant using a modified parallel path Burgener nebulizer has been accomplished. Once generated, atomic species are stable in water, having a half-life of 2.2 min, and can be preconcentrated for subsequent quantitation. Although the initial products of the reduction reaction appear to be free atoms, subsequent interaction with nascent hydrogen gives rise to the molecular hydride in a transformation moderated by the chemistry of surface groups exposed to the reaction products. Use of a glass spray chamber results in a predominance of atomic vapor whereas a polymeric spray chamber releases the volatile molecular species.