It is well established that some hydrogen bonded chelates undergo proton transfer in the singlet excited state resulting in a significantly red-shifted emission band.“,?’ The quantum yield of this fluorescence is generally low, but there are known examples in which it is fairly large, for example in the case of salicylamide.“’ Salicylamide is chemically stable and has very good radiation and photochemical stability. The fluorescence of salicylamide, with a maximum about 430-440 nm, overlaps the region of maximum sensitivity of photomultipliers used in commercial liquid scintillation counters. The large Stoke’s shift together with the very low cost (IO-30 times lower than typical scintillators currently available on the market) inspired us to investigate this compound as a potential scintillator in liquid scintillation counting. An Intertechnique SL30 liquid scintillation counter was used for radioactivity determination. Based upon the solubility as well as the energy transfer properties, p-xylene, alone or as a mixture with dioxane, was chosen as a solvent. For these solvents the optimum concentration of salicylamide varied between 2 and 3 g/L. Counting efficiencies in the vicinity of 75Y6 were easily achieved for solutions of salicylamide in p-xylene containing a “C-labelled standard. The addition of up to 5% water by volume to the salicylamide solution (3 g,L) in the mixed solvent (pxylene-dioxane-ethanol, 8:2:5) caused a small decrease in Table I. Counting efficiency (in “,) of a “‘Cl-lab&d standard in solutions of salicylamide and salicylic acid at a concentrafion Z g/L in various solvents