Application of total-reflection X-ray fluorescence spectrometry to the analysis of airborne particulate matter

Two fast and simple methods for the collection and characterization of airborne particulate matter were developed. Airborne dust was collected by filtration and by impaction with a six-stage Berner impactor. For both methods cellulose nitrate filters were used as collection media. The exposed parts of the filters were punched out and digested with a cool-plasma asher (CPA). After dissolving the residue with nitric acid and addition of an internal standard element, the analysis was carried out by total-reflection X-ray fluorescence spectrometry (TXRF). The collection time could be reduced to less than 1 h and trace elements be determined in the range of ng m(-3). The detection, however, was limited by blank values caused by the sampling devices, especially by the impactor made of stainless steel. High blank values of chromium, manganese, iron and nickel as typical constituents of stainless steel were found. To avoid these high blanks, a more suitable material was chosen for the construction of an impactor of the same type. Hereby the blank values could be reduced to below the detection limits of about 100 pg m(-3). (C) 1997 Elsevier Science B.V.