The concentration of lead in blood reflects recent exposure and is extensively utilized for the biological monitoring of population exposed to this metal. Graphite furnace atomic absorption spectrometry is the method of choice for the determination of lead in blood. Attempts have been made to overcome matrix interferences and to improve accuracy and precision. In this work, blood samples were directly diluted with either 1% Triton X-100 in 0.2% nitric acid or 0.1% Triton X-100 in 6.4 x 10(-3) nitric acid. Ammonium phosphate and magnesium nitrate were used as matrix modifiers. Standard reference materials were analyzed to verify the accuracy and precision of this technique. Best accuracy was obtained with samples diluted with 1% Triton X-100 in 0.2% nitric acid, especially for lower concentrations of lead, further indicating that this method is an efficient technique to determine lead in whole blood.
