A semiautomated system for analysis of metals in biological materials and its application to mass determination of cadmium in blood.

A semiautomated system was developed for the determination of metals in biological materials by the combination of block-digestion-autosampler-flameless atomic absorption spectrophotometry. For block-digestion which can mineralize 144 samples in 10 h, a Pyrex micro Kjeldahl tube of a special shape was designed when applied to the mass analyses of cadmium in 1761 blood samples from non-exposed subjects, the system as a whole was sensitive enough with the lowest detection limit of 0.2 ng cadmium/ml blood, and able to measure about 50 samples every day, essentially without aid. Experiences are described with necessary comments.