Multivariate calibration and spectrum position correction for simultaneous determination of alpha and beta emitting plutonium isotopes by liquid scintillation

A new approach to the determination of alpha and beta emitting plutonium isotopes is presented here. Liquid scintillation (LS) was used as a single detection technique. The lack of resolution of LS was overcome by applying multivariate calibration. An important drawback is the spectral instability, which is related to the extraction procedure used in the preparation of the samples. The effect of spectral instability was corrected by using a quenching composition parameter. Furthermore, replicate determinations should be performed. The procedure can be applied to the simultaneous determination of beta 241Pu and alpha 242Pu, 238Pu and 239+240Pu activities in environmental samples, which is faster than separate determination of alpha and beta emitters.