The measurement of cadmium in biological materials, using graphite furnaceatomic absorption spectrometry with Zeeman background correction

Cadmium (Cd), a toxic heavy metal and probable carcinogen in humans, appear s to have potential anti-cancer activity in pre-clinical systems. This obse rvation led us to develop a method for measuring cellular Cd and DNA-bound Cd following micromolar exposures to cadmium dichloride. Cultured human ova rian cancer cell lines were used. Following low level exposures to cadmium dichloride (CdCl2), atomic absorption spectrometry with Zeeman background c orrection was used to measure total cell associated Cd in wet-ashed cells, and the lower limits of detection was at 100 pg of Cd per 10(6) cells. In c ellular DNA isolated by cesium chloride density gradient centrifugation, le vels of 1.5 Cd lesions (Cd molecules) per 10(6) nucleotides were reproducib ly detected. Standard curves with 'spiked' samples yielded 76.4+/-6.7% reco very when using picogram quantities of Cd. Manipulation of the total amount of biological material used, can further improve detection limits. Thus, t his method is suitable for the detection of Cd in biological matrixes after low levels of Cd exposure, and shows good performance in terms of the leve l of sensitivity and reproducibility.