Identification of lead in metal food can seams using Co-57 RXRFS

Radioisotope-induced X-ray fluorescence spectrometry procedures developed f or screening solder for Ph are described. By using Co-57 as an excitation s ource, food cans with Pb-soldered seams were easily distinguished from othe r types of metal cans. Limits of detection (3 sigma) for Ph in metal food c an seams were 0.1 and 0.3 mg Pb/cm(2) for count times of 1 hour and 3 minut es, respectively. Pb/Sn ratios were determined for commercial solders conta ining 0.6% to 84% Pb. Pb content was quantified as low as 0.07%, and Bi and Sb content could be determined for some commercial solders.