Time-resolved signals from particles injected into the inductively coupled plasma

Atomic emission signals derived from single particles in the 1–10 µm size range have been observed after injection of refractory oxides and silicates into the inductively coupled plasma by the nebulization of dilute suspensions. Detection limits by mass are in the 1 × 10–13–1 × 10–11 g range because of the discrete nature of the signal and the low 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 identification of uncommon particles in complex mixtures.