Determination of cadmium, cobalt, iron, nickel and lead in Venezuelan cigarettes by electrothermal atomic absorption spectrometry

Abstract

An electrothermal atomic absorption spectrometric method for the determination of Cd, Co, Fe, Ni and Pb in the constituent parts of Venezuelan cigarettes before and after smoking, is described. Rapid and convenient sample treatment was achieved by means of microwave wet acid digestion. Analyses were performed under optimized conditions using deuterium arc background correction. Atomization was carried out using the L'vov platform and tube-in-tube techniques. Similar accuracy, sensitivity and precision were obtained with both types of atomizer, but the latter provided a longer useful lifetime. Relative standard deviations for aqueous standards of the analyte of interest ranged from 0.66 to 1.28%. Detection limits, in µg ml^–1, were 3.87 × 10^–5 for Cd, 8.03 × 10^–4 for Co, 9.64 × 10^–4 for Ni and 5.34 × 10^–4 for Pb. The detection limit for Fe, determined at 373.7 nm, an absorption line less sensitive than the resonance line, was 5.04 × 10^–2µg ml^–1. The accuracy of the results was checked against National Institute of Standards and Technology Standard Reference Materials and by recovery studies. The results show that Venezuelan cigarettes contain trace metal concentration levels that are similar to those in foreign cigarette brands. Most of the trace metal content found was in the tobacco, with Fe at the highest concentration followed by Pb, Ni, Cd and Co.