Time sequence particulate sampling and nuclear analysis

A review is given of a series of time-sequence sampling devices for atmospheric particles. The samplers considered are all designed around the sensitive analytical capabilities of Particle Induced X-ray Emission (PIXE) and other charged particle nuclear techniques. Time-sequence samplers, collecting for subsequent chemical (elemental) analysis, are distinguished from automatic devices giving instantaneous readings (optical devices), and automated samplers, which collect multiple samples on discrete substrates. Time-sequence samplers discussed typically sample from 30 to 200 intervals on a single set of substrates. The versatile interpretive possibilities from the multi-elemental, time- and size resolved data are illustrated with examples from industrial hygiene, mesoscale transport, crustal aerosol and visibility studies. Factors that have limited wide-spread acceptance of these samplers are discussed, and suggestions given for further lines of development.