Stability and reproducibility of gel-suspension samples for the liquid scintillation counting of¹⁴C using N-lauroyl-L-glutamic-α,γ-dibutylamide

Abstract

Stability and reproducibility of gel-suspension samples were investigated in order to evaluate the characteristic feature of the gel-suspension method for¹⁴C activity measurement. Commercially available gelling agent, N-lauroyl-L-glutamic-α,γ-dibutylamide, was used for the gelformatio of the samples. No change of the counting rate for the gel-suspension sample was observed for more than 2 years after the sample preparation. Four samples used for checking the reproducibility of the sample preparation method. The same values were obtained for the counting rate of¹⁴C activity within the counting error. No change of the counting rate was observed for the “re-gelated” sample. These results show that the gel-suspension method is appropriate for the¹⁴C activity measurement by the liquid scintillation method and is useful for a long-term preservation of the sample for repeated measurement.