Determination of thallium in biological material by flame spectrophotometry and atomic absorption

Abstract

Flame-spectrophotometric and atomic-absorption methods of assaying trace amounts of thallium in biological material have been investigated. With the Perkin-Elmer, Model 303, spectrophotometer atomic absorption is the more sensitive and yields detection limits comparable with those reported in the literature for the most sensitive types of flame-emission equipment. A simple and rapid method of micro sampling by using a tantalum boat is described. It enables nanogram amounts of thallium (down to 3 ng) in 50 to 100 µl of blood and urine to be determined with an accuracy and precision of 3 to 5 per cent. This represents an increase in sensitivity of at least twenty-five times over conventional atomic-absorption spectrophotometry. The results obtained with the tantalum boat are susceptible to inter-element interferences, and calibration by using the additions method is essential for accurate quantitative results.