Analysis of submicrogramme levels of cadmium in whole blood, urine and hair by graphite furnace atomic absorption spectroscopy.

Toxicological studies require the analysis of heavy metals in many widely differing samples. In this paper, a simple and accurate method is described for the determination of cadmium in whole blood, urine, and hair. The blood and urine samples were digested in nitric acid at 70 degrees C, and the hair was digested in a 1:1 mixture of nitric and sulphuric acid. Although a low temperature necessitated longer digestion, the operation was conveniently carried out overnight. The digestion and any subsequent extraction or dilution was carried out in the same tube. The methods used optimised digestion efficiency and minimised sample contamination. The method was also found to be precise and highly reproducible with relative standard deviation (RSD) values within 5%.