OPTIMIZATION OF THIN-LAYER METHODS IN THE ENERGY-DISPERSIVE FLUORESCENCE X-RAY SPECTROSCOPY OF INORGANIC ATMOSPHERIC POLLUTANTS

A comprehensive optimization process was carried out for applying thin -layer and thin-tablet methods in energy-dispersive fluorescence X-ray spectroscopy with respect to sampling of inorganic atmospheric pollut ants. The methods of sampling have been evaluated critically consideri ng the widest concentration range. Optimization was directed preferent ially towards the preparation of thin pressed pellets. An optimal dist ribution of dust particle sizes was defined which could significantly be influenced by the grinding process. Furthermore the measuring head geometry and the measuring process was optimized. The measuring and th e evaluating processes were controlled by complex software. The perfor mance of the method was evaluated by the determination of values for t he relative precision and the limit of detection for the optimal excit ation source Cd-109. Using the optimized parameters gravitation dust s ediment samples were analyzed mainly from city and industrial areas.