Abstract
Determination of cadmium in environmental water was studied by a coprecipitation method with diethyldithiocarbamate (DDTC) and zinc (II) and the subsequent graphite furnace atomic absorption spectrometry (GFAAS).
One milligram of zinc and 5 ml of 10 w/v% ammonium carbamate buffer were added to sample water containing cadmium, the pH of which was adjusted to 7.5-8.0, followed by adding 5 ml of 2 w/v% DDTC solution.
The precipitated DDTC complex including cadmium was collected onto a membrane filter (0.45μm), and then dissolved by heating with 25 ml of nitric acid (1+40). The solution was used as the sample solution for GFAAS. The detection limit for cadmium was 0.005μg/l, the lower limit of determination was 0.016μg/l in the case of 500 ml of sample water.
This method was not influenced by sample volume, and was satisfactorily applied to the determination of cadmium without any interfering effects of the copresent ions in environmental water.
