Method for rapid tritiated water extraction from environmental samples

Abstract

We have developed a thermal vacuum desorption process to rapidly extract water from environmental samples for tritium analysis. Thermal vacuum desorption allows for extraction of the moisture from the sample within a few hours in a form and quantity suitable for liquid scintillation counting and allows detection of tritium at the levels of <2 Bq/1 of milk, <0.5 Bq/g of vegetation, and <0.5 Bq/g of soil. We developed a prototype unit that can process batches of twenty or more samples within 24 hours. Early data shows that a high percentage of water is extracted reproducibly without enrichment or depletion of the tritium content. The quench coefficient of the extracted water is low allowing for accurate, direct liquid scintillation counting. In most samples, good comparison has been observed with results using freeze-dry lyophilization as the water extraction method. Introduction +

Study of the comparative dynamics of the incorporation of tissue free-water tritium (TFWT) in bulrushes (Typha latifolia) and carp (Cyprinus carpio) in the Almaraz nuclear power plant cooling reservoir

“…For the carp and bulrush samples, it was necessary to extract the free-water to determine the tissue free-water tritium (TFWT) by means of a pre-treatment consisting of an extractive Dean-Stark type distillation with cyclohexane (LIBRA, 2002). This extraction procedure is less troublesome to apply than other methods of extracting of the free-water fraction, such as liophilization or thermal desorption in vacuo (Failor et al, 1998;Choi et al, 2002), since the equipment used is much simpler. One starts with an appropriate aliquot of the sample -50 g-fresh for both the bulrushes and the carp muscle.…”