Microanalytical concept for multicomponent analysis of airborne particulate matter

Summary A microanalytical concept is presented that permits the determination of four ionic species (NH₄⁺, Cl^–, NO₃^–, SO₄^2–and 16 elements (Al, As, Cd, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Si, V, Zn) in minute samples of filter collected atmospheric particulate matter. The multistage procedure is based on consecutive aqueous extraction and acid digestion of the entire sample. Ion analysis of the extract is made by flow injection analysis (FIA) and single column ion chromatography (SCIC) with total consumption of only 50 l sample volume. Flame and furnace atomic absorption spectroscopy (AAS) is employed for element analysis after acid decomposition in a closed microwave digestion system. Using flow injection sample introduction for flame-AAS a liquid volume of 2 ml is sufficient for determination of 10 elements. Determination of the remaining 6 elements by graphite furnace AAS requires 1 ml. The quality assurance programme is briefly described. It includes the analysis of standard reference materials, intercomparison with other laboratories and the use of alternative methods for accuracy control.