Determination of aluminium-26 using a low-level liquid scintillation spectrometer

Abstract

The lack of a suitable tracer has severely limited the use of radioisotope tracer experiments in environmental and biological studies on aluminium. The only aluminium radioisotope with a half-life greater than 10 min is the long-lived positron emitter ²⁶Al (t_½ 7.2 × 10⁵ years). The expense of this nuclide and the difficulty in attaining sufficiently low determination limits with standard radioanalytical techniques have restricted its application as a radioactive tracer. The development of a simple method for the routine determination of ²⁶Al using Cerenkov counting and a Quantalus 1220 low-level liquid scintilation spectrometer is reported. For a 300 min counting time, determination limits of about 60 mBq in water samples and 120 mBq in biological (fish gill) samples can be attained. With these levels of determination, the use of ²⁶Al as a tracer is a viable technique for the study of aluminium in environmental and biological systems.