Working environment of tritium analysis for photoluminescence control

The conventional tritium analysis process using a liquid scintillation counter (LSC) requires over 24 h of waiting time to reduce the interference from the luminescence of the sample cocktail. The working efficiency of tritium measurement using an LSC worsens as the waiting time for luminescence decay increases. We hypothesize that this waiting time can be shortened by using light-emitting diode (LED) lamps as lighting equipment in a measurement laboratory because the emission spectra of some LED lamps contain no ultraviolet rays. Thus, a sample cocktail was prepared under an LED lamp. The count rate of this cocktail was reduced to the background of the LSC (ca. 3 cpm) within several hours. By contrast, the luminescence of a cocktail placed under daylight took approximately 100 h to decay. Therefore, the use of LED lamps is effective for luminescence control and shortening the waiting time in a measurement process.