Analytical performance of some methods for the determination of trace elements in lichens used as air quality assessment

A study was carried out in Havana City using lichen as monitor of air pollution. The concentration of several trace elements (Ca, Mn, Fe, Ni, Cu, Zn, Sr, Cd, Pb) in a total of 225 samples was determined by Total Reflection X Ray Fluorescence (TRXRF), Flame Atomic Absorption Spectroscopy (FAAS) and Anodic Stripping Voltammetry (ASV). In addition several Biological Certified Reference Materials (CRM's) were analyzed in order to assess the analytical performance of the results. In general a relatively good agreement was found among the techniques. No significant differences were found between the obtained results and the certified reference values. (author)