A critical evaluation of fluorometric methods for determination of selenium in plant materials with 2,3-diaminonaphthalene

The published methods for fluorometric determination of Se in plants are reviewed, with particular attention to those using 2,3-diaminonaphthalene as the fluorometric reagent. Two steps in the analysis are shown to be critical: the final stages of the digestion and the complete conversion of the Se to Se(IV). A modified experimental procedure is given.