Determination of mixtures of alpha emitting isotopes (242Pu, 239+240Pu, 238Pu) by using liquid scintillation–moving curve fitting Original Research Article

A new method for the simultaneous determination of alpha emitting plutonium isotopes based on liquid scintillation spectrometry and moving curve fitting (LS–MCF) is presented. This method overcomes the instability of the spectrum position by introducing in the model some freedom in the band location. The method proposed has a higher detection efficiency than that of the classical semiconductor alpha spectrometry. Therefore, it can be used to process smaller samples and has the additional advantage of being a relatively quick procedure. With regard to the use of multivariate calibration, LS–MCF reduces the data treatment time because it does not require a previous spectrum position correction. LS–MCF can also be applied to samples with low activity levels.