Monitoring of Diarhettic Shellfish Poisons in Aquatic Environment by Solid Phase Adsorbent Toxin Tracking Technology

Abstract:

Due to the deteriorating marine environment and the repetitive red tides, harmful pollutions with shellfish toxins have caused increasing concerns. Diarhettic shellfish poisons (DSP) are one type of the most dangerous shellfish toxins. To develop an effective method of collecting DSP from sea water, we evaluated the adsorption efficiency of HP20 resin for four common diarhettic shellfish poisons including okadaic acid (OA), dinophysistoxin-1 (DTX-1), dinophysistoxin-2 (DTX-2), and gymnodimine (GYM) in the seawater column, based on the solid phase adsorbent and toxin tracking (SPATT) technology. The distribution of DSPs in the seawater column and their levels in shellfish were measured. We selected five sampling sites in an oyster farming area, collected samples of both the seawater and oysters on a weekly basis, and studied the correlation between the contents of DSPs in the seawater and those in oysters. During a 7-day sampling period, HP-20 resin accumulated showed high adsorption ratios for the four DSPs, which were 98.9%, 103.3%, 93.5%, and 76.6% for OA, DTX-1, DTX-2, and GYM respectively. The DSPs were detected throughout the entire study period except for DTX-2. The concentrations of OA, DTX-1, and GYM were 20.451–422.35 µg/kg, 15.954–368.678 µg/kg, and 20.452–282.231 µg/kg respectively. During the monitoring period, the contents of the three DSPs in the seawater varied temporally and showed a uniform pattern of distribution. The levels of DSPs in oysters were raised along with the increase of DSPs in the seawater with a latent appearance of peak values. These results suggested that our method should be efficient in the simultaneous temporal and spatial monitoring of DSPs in aquatic environments and in shellfish samples. This method may also be applied in DSP early warning system.