Evaluation of different parameters affecting the liquid scintillation spectrometry measurement of gross alpha and beta index in water samples

► Developed method for simultaneously quantifying gross alpha and gross beta indexes based on LSC was as accurate and precise as the results obtained from methods based on gas proportional counting and ZnS alpha counting. ► Alpha/beta crossover and/or quenching corrections were applied and the results obtained did not improve accuracy within 25% dispersion, a widespread acceptance limit for gross alpha and beta counting. ► Interferences corrections should not be neglected if alpha and beta count rates differ in one order of magnitude or more. ► Limitation of the technique lies on high quenched samples; procedure was no longer reliable due to the interrelated influence of quenching on the counting efficiency and also on alpha and beta interferences.