Determination of lead in sheep's blood by graphite furnace atomic absorption spectrometry using a modified chelation and extraction procedure

Abstract

Ammonium tetramethylene dithiocarbamate and isobutyl methyl ketone are used to chelate and extract lead from haemolysed whole blood in a procedure modified for use with a graphite furnace. The ketone layer separates readily without centrifugation. With a pre-atomisation temperature of 350 °C to prevent loss of chelated lead and an atomisation temperature of 1600 °C background correction is unnecessary, and the tubes can withstand about 1000 firings. The method has a detection limit of about 0.018 µg ml^–1 of lead. The between-run precision for a pooled sample of ovine blood containing 0.135 µg ml^–1 of lead (0.100 µg ml^–1 of added lead) was 4.1%, calculated from the results of 41 analyses carried out over a period of 2 months.