Determination of aluminium in lutetium by instrumental neutron activation analysis

In lutetium metal 45 ppm aluminium have been determined by instrumental neutron activation analysis. Interference from the very intensive gamma-radiation of sup(176m)Lu was eliminated by application of lead filters. The absolute detection limit is determined by the aluminium content of the blank graphite irradiation vials, which was found to be equal with 0.25 μg Al/g graphite. The tenfold of the variance 0.7 μg Al was estimated as detection limit. The relative determination limit is dictated by the interfering matrix activity, which was estimated to be around 3 ppm. (T.G.)