Microwave decomposition for airborne particulate matter for the determination of trace elements by inductively coupled plasma mass spectrometry

Abstract

A microwave digestion method utilizing an acid mixture of HNO₃–HClO₄–HF (3 + 5 + 2 v/v) in closed vessels was developed for the determination of major, minor and trace elements in very small amounts of airborne particulate matter collected on Teflon filters by a dichotomous sampler, and was tested on NIST Standard Reference Material (SRM 1648 Urban Particulate Matter). Analyses were carried out by inductively coupled plasma mass spectrometry (ICP-MS). Sixteen elements (Al, As, Ba, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sb, V and Zn) were determined. The results generally showed high reproducibility and good agreement with the certified values, except for As and Cr. The feasibility of applying the microwave digestion pre-treatment with ICP-MS to real samples was also examined. It was demonstrated that the suggested method is more suitable than conventional methods for real sample analysis.