SAMPLE COLLECTION AND PREPARATION FOR ANALYSIS OF AIRBORNE PARTICULATE MATTER BY TOTAL-REFLECTION X-RAY-FLUORESCENCE SPECTROMETRY

The steady interest in clarifying the relevance of atmospheric particl es for health risks requires fast and easy to handle methods for the c ollection and characterization of airborne particulate matter. For the present study, airborne dust was collected by filtration as well as b y impaction with a six stage Berner type impactor. Filtration was perf ormed with cellulose nitrate filters, and in the Berner type impactor a thin spray film was employed as collection medium. The exposed porti ons of both materials were punched out and digested. Three different d igestion techniques were studied and intercompared: open digestion (OD ) with nitric acid and hydrogen peroxide, high pressure acid digestion (HPA), and cool plasma ashing (CPA). Decomposition by CPA showed high est reliability and practicability for these materials. After digestio n of the samples, the residues were dissolved with nitric and hydrochl oric acid, mixed with an internal standard element and analyzed by Tot al Reflection X-Ray Fluorescence Spectrometry (TXRF). Due to the high detection power of TXRF, the sampling time could be reduced to less th an 1 h. By this means it was possible to collect and analyze several s amples successively during one day. A diurnal variation was establishe d with both sampling systems in parallel.