SPECIES DETERMINATION OF SELENIUM IN MARINE PLANKTON BODY-FLUID

The vertical distributions of Se(IV) and organic selenium in open sea are similar to those of nutrients. It was therefore considered that Se (IV) and organic selenium in sea water were supplied from the decompos ition of marine biological material. In this study, marine planktons w ere used as biological material. Some pretreatment procedures were inv estigated for the chemical speciation of selenium in marine plankton s amples. Selenium was determined by 2,3-diaminonaphthalene (DAN) fluoro metry. The interference of coexistent fluorescent materials for the fl uorescence spectrum of 4,5-piazselenol (Se-DAN complex) was effectivel y removed by back-extraction with concentrated nitric acid, followed b y a wet-ashing method, and dilution with distilled water to 80 times t he initial sample solution. The contents of selenium species in plankt on body fluid changed with time. The sample pretreatment must therefor e be carried out immediately after plankton thawing.