Free and organically bound tritium by liquid scintillation

Biota

Sediment

H

This method both in French (original language) and English (italic characters) specifies the minimum requirements and laboratory methods for the preparation of samples and material to carry out analysis of Tritium in environmental samples with liquid scintillation.

After collection in the field, the samples are either frozen or keep fresh until return to the laboratory taking the necessary precautions to avoid any exchange with the air (samples must be put in sealed bags under vacuum as soon as possible after sampling). In order to determine tritium concentrations, environmental samples are generally first freeze-dried. The tritium obtained in the condensate is the HTO fraction of the sample (tissue free water tritium). Then the residue is burnt in a special tubular furnace with oxygen in the presence of a catalyst. The water fraction trapped, designated as Organically Bound Tritium (OBT), is adjusted at pH 7, distilled and, measured using a liquid scintillation counter (Pointurier et al., 2004; Cossonnet et al., 2009).