STUDIES ON THE DETERMINATION OF THE METAL CONTENT OF AIRBORNE-PARTICULATES BY FURNACE ATOMIZATION NONTHERMAL EXCITATION SPECTROMETRY

Quantifying the metal content of airborne particulates is of outstanding relevance because of its potentially toxic and carcinogenic behaviour. The most widely used measuring strategy is based on filtration of particles from ambient air followed by analysis of the loaded filter tissue after wet digestion. In the present work an alternative approach was investigated which is based on drawing the air through the wall of a porous graphite tube in such a way that particulates are collected on the inner surface of the tube. Moreover, the graphite tube acts not only as an efficient collector but can also be employed as an electrothermal atomizer when applying furnace atomization non-thermal excitation spectrometry. If combined with an echelle polychromator, simultaneous multi-element determinations are possible. The amount of metals in air dust collected in this way were determined at the ng m-3 level, with limits of detection, calculated on the 3s criterion, ranging between 0.1 and 1 ng m-3. The precision represented by the relative standard deviation varied from 0.12 to 0.26 depending upon the concentration of metals in the air.