On the estimation of precision in the measurement of elemental concentration in atmospheric particulate

The measurement of elemental concentration of atmospheric particulate involves collection, preparation and processing protocols that contribute to the result uncertainty, which is often attributed to the sole error given by the final used analytical technique. In this work, a detailed estimation of precision to associate to the characterization of PM1 collected near the airstrip of Venice airport is presented. This evaluation is particularly critical for example in the analyses performed by Positive Matrix Factorization receptor model, that allows to identify and to estimate the emission contribution of the sources affecting the atmosphere of a monitored area. PM1 air concentration was determined gravimetrically after appropriate stabilization of the samples, that were subsequently digested with a mixture of acids. The digested samples were then twice diluted, and analyzed by Inductively Coupled Plasma – Optical Emission Spectroscopy. The processing steps that give the higher contribution to the result uncertainty are pointed out.