PL
W krajowych naturalnych wodach mineralnych oraz sokach owocowych oznaczano śladowe zawartości selenu wykorzystując trzy niezależne metody spektralne: 1 -metodę absorpcyjnych widm atomowych (ASA); 2-metodę spektrofotometrii absorpcyjnej (UV - VIS) oraz 3-metodę spektrofluorymetryczną (SF). Badania nasze wykazały, że zawartość selenu w badanych próbkach jest bardzo mała i nie przekracza poziomu 0,464 µg/dm3.
EN
Considering the essential nutritional role of selenium and the necessity to assess its contribution to the environmental risk, the problem of reliable determination of selenium in typical food products continues to be very important. In this work, the authors determined trace quantities of selenium in various commercial natural mineral waters and fruit juices by three independent methods: 1) atomic absorption spectrometry (AAS), 2) spectrophotometry (UV-VIS), and 3) spectrofluorometry (SF). A Prolabo (France) MX 350 Maxidigest microwave oven was used to mineralise the samples. Hydrochloric acid and 3,3'-diaminobenzidine (DAB), which forms violet/yellow-coloured piazoselenium with SeO32-, were added to the colourless clear mineralisates. Absorbancy readings of the coloured toluene solutions were taken at the wavelength of λ = 420 nm (UV-VIS) or 265/563 nm (SF). With the AAS method, SeO32- -containing mineralisates were directly analysed. Selenium content in the analysed samples was very low, within 0.464 µg/l. The results also show a considerable variation in selenium content of the examined natural mineral waters and fruit juices.