DETERMINATION OF DINOPHYSIS TOXIN-3 BY THE LC-LC METHOD WITH FLUOROMETRIC DETECTION

A highly sensitive HPLC method for the determination of acid dinophysi s toxins-3 (DTX-3s; 7-O-acyl-35-methylokadaic acids) by labeling 2-(an thracene-2,3-dicarboximido)ethyl trifluoromethanesulfonate (AE-OTf) ha s been reported. The digestive glands of mussels or scallops were homo genized with 2-propanol, followed by extraction with hexane/ethyl acet ate. After evaporation of the solvent, they were labeled with AE-OTf i n dry acetonitrile. Then, after cleaning up with a silica-gel short co lumn, the fluorescent derivatives were injected into an HPLC system. T n this system, the derivatives were at first separated on a phenylated silicagel column; then, only the target fraction was introduced into a separation column (an ODS column) by a valve device for switching th e column. The 7-O-palmitoyl DTX-3 derivative could be determined in th e range of 1.4 - 284 fmol (1.5 - 300 pg) on the column. The detection limit was 0.57 fmol (0.6 pg, S/N=3).