Limit of detection for the determination of Pt in biological material by RNAA using electrolytic separation of gold

Neutron activation analysis based on the¹⁹⁹Au indicator for platinum requires the separation of gold at high radiochemical purity. The limit of detection is strongly affected by the presence of gold; with a gold content of 50 pg/g, irradiating for 5 days at 5·10¹³ n/cm²s is needed to achieve a limit of detection of approximately 30 pg/g. In this case the nuclear interference from gold will exceed the level of platinum by several orders of magnitude and has to be determined with exceedingly high precision. Preliminary results for SRM 1577 Bovine Liver with 95% yield gave consistent results for Au, but Pt could not be detected.