Determination of cadmium by chemical vapour generation coupled with atomic fluorescence spectrometry
Abstrakt
Chemical vapour generation of cadmium in a four-channel system using Cr(3+)/KCN as additives was successfully coupled to an in-house constructed nondispersive atomic fluorescence spectrometer. The atomization conditions in two atomizers - a miniature diffusion flame and a flame-in-gas-shield atomizer - were optimized.
Interfering effects of several hydride forming elements were studied and it was found that Sn, Sb, As, Bi, Hg and Se exhibited no interference on Cd determination up to 100 μg L(-1) while significant interference (response decreased by 13%) was identified for Pb even at 10 μg L(-1). The limits of detection were 1.4 and 0.42 ng L(-1) for the miniature diffusion flame and the flame-in-gas-shield atomizer, respectively.
The accuracy of the developed methodology employing the flame-ingas-shield atomizer was successfully verified by analysis of a certified reference material of fresh water NIST 1643f.