Survey of the distribution of red tide toxins (okadaic acid and dinophytoxin-1) in the Dalian Bay sea area of China by micellar electrokinetic capillary chromatography

Two kinds of diarrhoetic shellfish toxins, okadaic acid (OA) and dinophytox in-1 (DTX-1) were determined by micellar electrokinetic capillary chromatog raphy (MEKC) with ultraviolet detection. A detection limit of 3.25 mug/mL f or both of them was achieved. The UV absorbance of these toxins measured at 200 nm showed good linearity in the range of 6.25-200 mug/mL with R = 0.99 2 for OA and 0.997 for DTX-1. Three kinds of shellfish (Chlamys farreri, My tilus edulis and Ruditaps philippinarum) collected from eight locations (sa mpling in the intertidal zone) along the Dalian Bay sea area of China were surveyed in February and May of 2000. Results indicated that three kinds of shellfish were contaminated by OA and DTX-1. Based on per gram of hepatopa ncreas. in February, the contamination contents ranged from 0 to 1.26 mug f or OA and from 0 to 1.82 mug for DTX-1, and in May, the contents ranged fro m 0 to 1.45 mug for CA and 0 to 2.56 mug for DTX-1. Among the eight locatio ns, Hei Shi Jiao and Long Wang Tang were the most contaminated areas. Of th e three kinds of shellfish, Mytilus edulis was the most significant species in accumulating CA and DTX-1.