Some analytical problems encountered for trace elements determination in the airborne particulate matter of urban and rural areas

The determination of trace elements (TE) in airborne particulate matter col lected onto filters requires an accurate evaluation of the entire analytica l procedure. Since many elements have to be determined at a few milligrams of air dust at nanogram levels, possible sources of error can arise from un controlled parameters such as blank of the filters, sample homogeneity, pre -analytical treatment, primary and comparator standards. These potential cr itical points are presented here and discussed on the basis of the experien ce developed in our laboratory in previous studies where several TE monitor ing campaigns have been performed for air particulate matter collected in u rban as well as in rural residential areas of north Italy. Instrumental neu tron activation analysis (INAA) and electrothermal atomic absorption spectr oscopy (ET-AAS) have been used for the investigation of more than 30 trace elements. (C) 2000 Elsevier Science B.V. All rights reserved.