Simultaneous determination of cadmium, lead, and copper in the constituent parts of the illegal cigarettes by Square Wave Anodic Stripping Voltammetry

Abstract

Smoking is a present-day disease that affects a significant part of the world population and the search for analytical data regarding toxic elements in cigarettes is still an issue of analytical interest. This work describes an efficient, fast, and reliable analytical methodology for the determination of Cd, Pb and Cu in different constituent parts of cigarettes (filters, ashes, and tobacco) samples using Square Wave Anodic Stripping Voltammetry. The electrochemical system consisted of a cell with three electrodes: work – mercury film modified glassy carbon electrode, reference – Ag/AgCl(sat) and auxiliary – platinum, using as supporting electrolyte hydrochloric acid 10 mmol L−1. The results obtained after the previous digestion of the samples in a microwave oven confirmed the efficiency of the procedure. The method was validated using 11 samples and the results showed recovery values between 80 and 111%. The accuracy was also evaluated by means of a matching reference sample of tomato leaves to prove the reliability of the method. The detection limits were 0.72, 0.89 and 1.43 μg L−1 for Cd, Pb and Cu, respectively. Regarding the analytical results, the cadmium contents remained below the detection limits, while the average values found for lead were in the range 0.21, 2.84 and 4.86 μg/cigarette for the post-burning filter, ashes, and tobacco, respectively. The average values found of copper were in the range 0.49, 4.22 and 12.8 μg/cigarette for the post-burning filter, ashes, and tobacco, respectively.