Trace analysis of lead in blood, aluminium and manganese in serum and chromium in urine by graphite furnace atomic absorption spectrometry.

A graphite furnace atomizer with automatic sampler is used to measure low levels of trace metals in biological samples by atomic absorption spectrometry. With blood and serum, the sample treatment consists of diluting (1:1) with aqueous Triton X-100 solution, centrifuging in the case of blood, and dispensing the liquid directly into a pyrolytic coated graphite tube. Sample volumes for blood and serum range from 5 to 10 microL. Stabilized urine (25 microL) is analyzed directly. The possibility of contamination is minimized by this simple procedure. The methods described minimize sample handling and involve reagents which are virtually free of contamination of the analytes. Background correction is necessary except for the determination of aluminium in serum, and precisions range from 0.7% to 4.3% RSD. The standard additions technique is used to establish the calibration and the required volume of sample and aqueous addition is automatically dispensed directly into the graphite tube.