ENERGY-DISPERSIVE X-RAY-FLUORESCENCE ANALYSIS OF THIN AND INTERMEDIATE ENVIRONMENTAL-SAMPLES

Energy-dispersive x-ray fluorescence (EDXRF) was applied to the analys is of environmental samples, such as algae, microalgae and marine sedi ments, prepared as thin samples by mixing powder with two-component ep oxy resins, and as intermediate samples in the form of pellets. Furthe r, sulphur, the concentration of which is used as an index of degradat ion, was analyzed ill situ on a 16th century mural painting inside the church of S. Stefano Rotondo in Rome. Finally, lead was monitored in air samples from the city of Lecce and a map of the Pb distribution at various locations in the city was obtained. The equipment for EDXRF a nalysis is based on miniaturized x-ray tubes (Oxford, 30 kV, 0.1 mA, M o or Pd anodes; or Hamamatsu, 10 kV, 0.3 mA, Ca anode) and on thermoel ectrically cooled Si-PIN detectors, having an energy resolution of 250 eV at 5.9 keV. Lead was excited,vith a Gilardoni x-ray tube (Radiolig ht, 80 kV, 5 mA, W anode and Mo secondary target) and x-rays were dete cted with an HpGe detector with an energy resolution of 160 eV at 5.9 keV. (C) 1998 John Wiley & Sons, Ltd.