How to collect relevant ambient and occupational air samples for plasma based spectrochemical analysis

Because of analytical progress these last decades, plasma-based spectrochemical methods can now reach ranges of concentrations and achieve levels of precision and reproducibility which cover most of the needs in term of quantification of element or chemical species in their environment.
The main source of uncertainty in this determination results in the significance of the collected sample with regard to its environment and, in lesser extent, the preparation of the sample for analysis. In the case of air sampling, the sampling strategy plays a major role in this uncertainty because it has to take into account both the spatial and temporal variability of the chemical agent concentration in the air, as well as the objective of the measurement itself. For environmental health issues, the objective of measurement is to determine levels of concentration of chemical agents in ambient air to which the whole population may be exposed. In industrial hygiene, this objective is mainly the occupational exposure assessment to chemical agents by sampling and analysis of workplace air in the immediate vicinity of workers. This difference is fundamental and deeply influences sampling and associated analytical methods to assess concentrations of chemical agents in the air.
This short course will then illustrate with concrete examples the resulting differences between occupational and environmental health issues for the following steps in exposure assessment:
· Definition of the conventional size-fractions;
· Personal/static air samplers (efficiency, bias);
· Working ranges of concentrations (flow rates, sampling durations);
· Sample Preparation (sampling medium, digestion methods for refractory elements, direct analysis, sampler wall deposits);
· Analysis.