A RAPID ZEEMAN GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRIC METHOD FOR THE DETERMINATION OF LEAD IN BLOOD

A method is described for the rapid determination of lead in blood. About 100 samples are processed in a 7.5-h shift, with two replicate injections per sample. Whole blood, obtained either by venipuncture or fingerstick, is diluted 1:10 in a phosphate matrix modifier containing Triton X-100 and dilute nitric acid, and 12 mul of the diluted blood is deposited in the graphite furnace. An entire cycle is completed every 90 s. Aqueous standards in the matrix modifier are used for calibration. The within-run standard deviation is typically about 0.25 mug/dl at low concentrations, indicative of very good precision. Considerable amounts of data using various reference materials are provided establishing the accuracy of the method to better than 1 mug/dl at low concentrations (c. 10 mug/dl) of blood lead. The speed and precision of the method is made possible by the use of the new transversely heated graphite furnace with a longitudinal Zeeman field background correction system.