Determination of cadmium by electrothermal atomic absorption spectrometry

Abstract

In the presence of organic compounds, such as EDTA, citric acid or triethanolamine, the absorbance signal of Cd during atomization in a tube of electrographite or covered with pyrolytic graphite appears at a lower temperature than the signal from CdCl2. Some of these compounds, e.g. EDTA, eliminate the interfering effect of NaCl and MgCl2. With urine, however, addition of these compounds often causes splitting of the single absorbance pulse of Cd or an increase of one of the components of a splitted pulse. Addition of a simple modifier HNO3 is therefore recommended for analyses of urine using atomization in a tube of electrographite. The evaluation of the cadmium concentration was done from integrated absorbances by the method of standard additions.