Extreme sensitivity in trace element detection

Abstract

A technique is demonstrated which can detect extremely low levels of trace elements. This technique uses multicolor, selective multiphoton ionization of a trace impurity species followed by ion-induced nucleation in a supersaturated vapor, which allows the detection of single ions at atmospheric pressures. The combination of these two processes has the potential for use in detection of a wide range of atmospheric contaminants at extremely low levels. This technique is demonstrated by the detection of mercury atoms at a concentration of less than 1 part per 1014 particles. © Springer-Verlag 1999.