A simple method of the recovery of selenium from food samples for the determination by ICP-MS

Abstract By using subcritical water (SW), a simple method of the recovery of selenium (Se) from food samples was developed for the determination of Se by inductively coupled plasma mass spectrometry (ICP-MS). A portion of powdery dried sample was precisely weighed and mixed with pure water (liquid/solid ratio, 100). This was placed in a sealed vessel, and heated in an electric oven. The resulting aqueous phase was analyzed for Se by ICP-MS. The optimum conditions for the recovery of Se were studied by using certified reference materials of biological samples (NMIJ-7402a and TORT-2). In order to validate the SW treatment as an analytical pretreatment, fourteen food samples under the optimum conditions (treatment temperature, 220 °C; time 120 min) were tested. The samples include fishes, shellfishes, meats, and dried seaweeds. The Se concentrations obtained using the SW treatment were about the same as those with the conventional method, microwave-assisted acid digestion. The dissolution behavior of Se during the SW treatment was clearly elucidated by using water extraction and SEC-ICP-MS analysis.