[en] A method is claimed of preparing a liquid scintillation system consisting in the separation of the mother liquor and the use of the organic extraction phase as a solvent for scintillators and scintillation admixtures. The system is designed for use in the analysis of liquid scintillator-based radiation sources, mainly of alpha and beta sources in which the sources are extracted using an organic solvent and separated in the organic phase and the mother liquor. The scintillators and the scintillation admixtures are added to the liquid scintillation system prior to extraction separation of the sources. (J.P.)