Fluorimetric determination of diarrhetic shellfish toxins in scallops and mussels by high-performance liquid chromatography.

The fluorimetric determination of okadaic acid (OA) and dinophysistoxin-1 (DTX-1), the principal toxins of diarrhetic poisoning, is reported. The digestive glands of mussels or scallops were homogenized with 2-propanol. OA and DTX-1 were extracted from the homogenate, with hexane-ethyl acetate and labelled with 2,3-(anthracenedicarboximido)ethyl trifluoromethanesulfonate in dry acetonitrile. After cleaning up by passage through a short silica gel column, the fluorescent derivatives were determined by HPLC. The derivatives were at first separated on a Develosil Ph-5 column, and only the target fraction obtained was introduced into a Develosil ODS K-5 column by a valve-switching device. Both toxins were determined in the range 2.5-500 pg, and the detection limits were 0.8 pg (OA) and 1.3 pg (DTX-1) with a signal-to-noise ratio of 3.