Extractive scintillators for alpha liquid scintillation counting: Anomalies in quenching evaluation

Two important effects in quenching evaluation when using some commercial ex tractive scintillators in alpha liquid scintillation counting are described . One affects the system quenching value but not the efficiency, while the other modifies the efficiency with no important change in the quenching. Fo r these cocktails, alternative procedures for efficiency evaluation must he chosen. We propose an inner standard procedure which gave adequate results in the application to different kinds of samples.