A CRITICAL EXAMINATION OF SOME NEWLY AVAILABLE STANDARDS FOR LIQUID SCINTILLATION COUNTING

Abstract Some newly available encapsulated sources of carbon-14 and tritium have been evaluated for their usefulness as accurate, convenient internal standards in liquid scintillation counting. They have been found to be as accurate and reproducible as claimed and provide the practitioner with a clean, rapid method for using the widely applicable internal standard method. The water-soluble tritium standard (sucrose) requires a minimum water concentration (1.3% for Aquasol-2) in a detergent cocktail before it will completely dissolve. Efficiency determination of colored and gelled samples is considerably simplified as is the preparation of quenched standard sets in any cocktail system.