MULTIVARIATE CALIBRATION AND SPECTRUM POSITION CORRECTION FOR SIMULTANEOUS DETERMINATION OF ALPHA-EMITTING AND BETA-EMITTING PLUTONIUM ISOTOPES BY LIQUID SCINTILLATION

A new approach to the determination of alpha and beta emitting plutoni um 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 sp ectral 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 ap plied to the simultaneous determination of beta Pu-241 and alpha Pu-24 2, Pu-238 and Pu239+240 activities in environmental samples, which is faster than separate determination of alpha and beta emitters. (C) 199 7 Elsevier Science B.V.