The use of chemical modifiers in the determination of cadmium in sewage sludge and tin in PVC by solid sampling-graphite furnace atomic absorption spectrometry

The effects of NH4H2PO4 and Pd as chemical modifiers in SS-GFAAS are studie d in the determination of Cd in sewage sludge and of Sn in PVC samples. Whe reas for Cd both modifiers act equally well whether Cd is in solution or in the solid sample, the effect of Pd on tin is different. To make the Pd mod ifier as effective on Sn in PVC as on Sn in solution a two-step pyrolysis m ust be introduced into the temperature programme. It is also shown that the contribution of the application of chemical modifiers to the final impreci sion of the determination is negligible compared to that introduced by the sample inhomogeneity. (C) 1999 Elsevier Science B.V. All rights reserved.