Chemical speciation of trace metals in fine airborne particles:: advances in operational performance of a new sequential extraction scheme

A speciation method of inorganic metal compounds in airborne particulate matter based on selective sequential extractions is described. The sequential leaching procedure was perfected for improvement of performance at different stages of scheme. The loss of fine particles during the leaching procedure was the main source of error that was assessed and corrected. Loss of sample volume due to the heating steps and due to the absorption on filter material was also a difficulty to solve. New experimental conditions were optimized for the operational scheme to remove the different sources of loss. Microwave assistance with an optimum programme as a heating system, filtration of extractable solutions, and the use of internal standards were the main contributions.