Abstract
Minute amounts of silver, copper, cadmium, lead and thallium in whole blood can be determined simultaneously by isotope dilution surface ionization mass spectrometry using 107Ag, 65Cu, 116Cd, 206Pb and 203Tl as spikes. A whole blood sample weighing 2~4 g is treated with a mixture of nitric and perchloric acids and evaporated to form a white residue. The residue is dissolved in a dilute nitric acid and spiked with 10-10 mol of the spikes. Metal components are separated from foreign elements by being shaked with a dithizone chloroform solution from which they are back extracted into a nitric acid solution. An aliquot of the solution is loaded onto the center of a rhenium single filament, ionization unit of a Hitachi RMU-6 type mass spectrometer. The present method can detect the presence of 10-15 mol of thallium and 10-14 mol of the other metals in the sample. Their concentrations can be measured with the relative error better than several percent, the best in comparison with those by the methods applied to blood samples during the past ten years.
