Determination of Metals in Airborne Particles by Electrothermal Vaporization Inductively Coupled Plasma Mass Spectrometry After Accumulation by Electrostatic Precipitation

Abstract

A method to determine metals in airborne particles by electrothermal vaporization ICP-MS after sampling by electrostatic precipitation into a graphite tube is described. A mobile sampler was used to collect samples. Calibration was performed with dried aerosol produced by the nebulization of a standard solution. For Cr, Fe, Mn, Cu, Zn, Sr, Cd, Sb, Ba and Pb, the absolute detection limits were in the picogram range. The high sensitivity allowed the monitoring of several metals in ambient air with a time resolution of hours. The precision was 10–15%. The addition of 5 µg g ^-1 of Na (as NaNO ₃ ) to the standard solutions improved the signal intensities and reduced the curvature of the calibration curves. The influence of CHF ₃ was investigated but subsequently abandoned owing to a general increase not only of the signals but also of the background.