Stabilization of the counting rate by irradiation of the liquid scintillation counting solutions with UVlight
Abstract
While counting certain compounds, labeled with tritium or S ^{35}, by liquid scintillation counting, we observed that the counting rates decreased rapidly during the first 23 hours. Even after this time, the counting rates continued to decline, but at a slower rate. The influence of temperature, agitation of the vials, and addition of alcohol upon this phenomenon was investigated. In each case the counting rates decreased, except with additions of 2 ml or more of ethanol. All ethanol additions to the stock solutions produced a quenching of the counting rates. However, an irradiation of the stock solutions with UVlight of 2537 Å (Hgline) stabilized the counting rates even without appearance of quenching. A possible theoretical explanation of these observations is given.
 Publication:

Nuclear Instruments and Methods
 Pub Date:
 July 1961
 DOI:
 10.1016/0029554X(61)901483
 Bibcode:
 1961NucIM..12..329L