Single Particle Characterization by Time-of-Flight Mass Spectrometry

We have built a particle analyzer capable of real-time detection and characterization of individual particles. Particle analysis is accomplished by pulsed laser ablation of a particle followed by time-of-flight mass spectrometry of the resulting atomic and molecular ions. The detected ions are characteristic of a particle's molecular composition. Particles of different sizes (0.02–10 μm) and compositions (ammonium sulfate, silica, rubidium nitrate, and cesium nitrate) have been detected and characterized. Even refractory materials, e.g. silica, are easily detected.