TIME-RESOLVED SIGNALS FROM PARTICLES INJECTED INTO THE INDUCTIVELY-COUPLED PLASMA

Atomic emission signals derived from single particles in the 1-10 mu m size range have been observed after injection of refractory oxides an d silicates into the inductively coupled plasma by the nebulization of dilate suspensions. Detection limits by mass are in the 1x10(-13)-1x1 0(-11) g range because of the discrete nature of the signal and the lo w background against which the signals are observed. True calibration is currently impossible because of the unavailability of particles of accurately known mass, but element-specific particle counting is easy and a valuable capability in itself for discrimination and identificat ion of uncommon particles in complex mixtures.