Determination of trace amounts of cadmium in sea water by a flameless atomic absorption method

Determination of trace amounts of cadmium in sea water has been developed by a flameless atomic absorption method using a carbon rod atomizer. Sea water is diluted with isopropyl alcohol and the white salt formed is removed by filtration, then the filtrate is fed to the instrument as a sample for measurement. A complete separation of the salt is not needed in this pre-treatment. The effect of the residual salt can be avoided by separating the atomic absorption of cadmium and the molecular absorption of the residual salt by means of controlling the temperature and the time of ashing and atomization of the sample in the carbon rod. The repeatability and the accuracy are 2.0--8.5% in the coefficient of variation and 0.8--5.3% respectively. (auth.)