Determination of inorganic thallium compounds in the particulate matter of emissions and workplace air by sequential dissolution.

Inorganic thallium compounds in the atmospheric particulate matter of emissions and in the workplace air of specific industrial production can be determined through selective sequential extractions: Tl(I) is separated from Tl(0) and Tl(III) in the first step, Tl(0) in the second one, while in the final extraction both Tl(III) soluble and insoluble compounds are determined. The procedure has been tested on 1633a Coal Fly Ash standard reference material. The thallium recovery was in the range 91 - 98%.