Transverse heated filter atomizer:: atomic absorption spectrometric determination of Pb and Cd in whole blood

A transverse heated filter atomizer ( THFA) was applied to the direct determination of Cd and Pb in blood, and its analytical performances were investigated using a Perkin Elmer SIMAA 6000 atomic absorption spectrometer. Seronorm human blood reference materials ( RM) and samples of bovine whole blood spiked with Pb were used for the method validation. The blood samples diluted 5 or 10 times with water to reduce their viscosity were injected in the THFA at temperature about 110 - 120degreesC together with blank or analyte solution in 0.2% HNO3. Compared to the transverse heated graphite atomizer with a platform ( THGA), the THFA provided significant reduction of non- specific background absorption and more than 90% recovery of Cd and Pb, without the use of chemical modifiers. The 'hot' sampling and injection of ethanol together with the blood solution improved repeatability of analytical signals. Periodical cleaning at elevated temperature after each 15 - 20 measurements prevented building up of solid residues in the THFA cavity. Limits of detection achieved for Cd and Pb were 0.05 and 1 mug L-1, respectively.