Online Sample Pretreatment Systems for Determination of Cadmium by the ETAAS Method

Trace and ultratrace determinations of cadmium in environmental and biological samples have become of increasing interest due to the high toxicity of this metal and because electrothermal atomic absorption spectrometry is probably the method of choice for its determination. The measured signals are, however, inherently very susceptible to the composition of the sample matrix and notably to variation within it. The most effective way to avoid these problems is to perform appropriate sample pretreatment such as preconcentration and separation. Such procedures are most advantageously performed in flow systems where all unit operations can be executed online. This paper reviews selected systems, such as solid-phase extraction, liquid-liquid extraction, coprecipitation and chemical vapor generation using to improve sample pretreatment for cadmium determination.