Development of a rapid, economical and sensitive method for the routine determination of excreted uranium in urine

A rapid and economical method, for the routine determination of excreted uranium in urine, which is capable of processing several hundred samples per week, with a detection limit of 2.5 mBq/L (alpha detection, counting overnight), is reported. The sample is mixed with an excess or equal volume of concentrated hydrochloric acid and the uranium is adsorbed onto ion exchange resin, where it is purified and eluted. The uranium can then either be electrodeposited for alpha spectrometry (AS) or extracted with a scintillant for photon electron rejecting alpha liquid scintillation spectrometry (PERALS). The whole method, up to the electrodeposition or extraction, takes 2 hours and may be automated using a standard Zymark workstation. The method has been validated by analyzing urine samples from uranium workers who have been shown to excrete up to 40 mBq/d total uranium