Determination of DSP toxins: comparative study of HPLC and bioassay to reduce the observation time of the mouse bioassay

 The progressive increase of DSP toxic episodes in shellfish in the last few years has generated a series of criticisms centered on the suitability of the mouse bioassay as a reference method to regulate the harvest of mussels from the growth area. The observation time in injected mice is currently fixed in 12 h by the actual Spanish rules. The revision of this time period and the lack of a established DSP toxin threshold which permits the commercialization of mussels contaminated under certain levels, are some of the actual demands from the industry. In this study, the results obtained in a comparative study of DSP toxic mussels are shown using the HPLC method and the mouse bioassay. Based on these results, we consider feasible the reduction to 5 h of the observation times of the mouse bioassay currently established in the actual legislation, as well as the establishment of a DSP-toxin threshold of 2 μg okadaic acid/g hepatopancreas, which regulates the possibility of harvesting and commercialization of contaminated mussels. Received: 10 October 1995/Accepted: 7 December 1995