Observations on impactors in flame atomic-absorption spectroscopy

Abstract

Five techniques for the evaluation of the effects of impact beads and other impactors in atomic-absorption spectroscopy are briefly evaluated: aerosol droplet size distributions; aspiration of dye solutions; aerosol sizing with a second species introduced through the bead; effects on linear absorbance range; and effects on the extent of chemical interferences. The advantages and disadvantages of each technique are considered, and the value of impact beads is critically appraised. A new strand impactor has been designed and found to be satisfactory. The use of a cascade impactor for direct measurement of droplet size distribution is simple and rapid and is more reliable for the elucidation of the effects of impactors on the aerosol size distribution of most interest in analytical spectroscopy.