Adsorption Of Diarrhetic Shellfish Toxins In Seawater By HP20 Resin And Its Application

In recent years, marine environment has been seriously polluted. Red tide disaster caused by eutrophication occurred frequently. Some harmful algal blooms can produce algal toxins, polluting shellfish and other marine organism though food chain. It threats to the food safety problem and human health. As a shellfish farming countries, aquaculture industry plays a most important position in mariculture economy. Compared to other countries, the shellfish toxin detection techniques are still lagging behind in China. Shellfish toxin monitoring system is not perfect, resulting in the problem of shellfish quality and safety.In this paper, the growth curve and the distribution of intra-and extra-cellular diarrhetic shellfish toxins were monitored in different initial cell density of Prorocentrum lima. DST toxins were acquired by extraction and purification. The influence of different salinities on kinetics and mechanisms of polymeric resin DST was explored by using solid phase adsorption toxin tracking technology (SPATT). HP20 resin were characterized to explore the adsorption mechanism of resin by scanning electron microscopy (SEM) and a gas sorption system. The effect of suspended particle on the process of shellfish accumulating toxin during mussel {Mytilus galloprovincialis) filtering water containing suspended particles and purified DST has been discussed. M. galloprovincialis were fed in the laboratory with P. lima and the coupling relation of SPATT adsorption toxins and mussels accumulating toxins were studied by using SPATT resin bags monitoring DST.The main contents and conclusions were summarized as follow:(1) Under batch culture conditions, the growth cycle of P. lima was more than 70 d, the unit cells of OA and DTX1 fluctuated in logarithmic growth phase and increased to the highest level in the stationary phase phase. But the total amount of DST gradually increased with incubation time and increased to the highest level in the stationary phase.(2)This adsorption process of HP20 resin on toxins has well fitted pseudo-secondary kinetics equation. It appears that film diffusion mainly controls the adsorption process in seawater at half of total salinity (13.5) which reaches a fastest adsorption rate. While intra-particle diffusion governs the adsorption of toxins in seawater at total natural salinity (27) which turns a slowest adsorption rate. It is the first time to confirm that molecules of OA and DTX1 toxins would enter into micropores (< 2 nm) and part mesopores (2 nm< diameter< 10 nm) of HP20 resin in natural seawater.(3) Mussels can filter dissolved OA and DTX1 from the seawater directly. Meanwhile, the presence of suspended particulate matter can affect the toxin-accumulated mechanism in the mussels. Additionally, mussels can accumulate the dissolved DST into shellfish tissue, and transferred the free states into esterification to achieve self-detoxification. The SPATT technology does have a good detection on the toxin contents in seawater, but the relationship between the adsorption contents and toxins accumulated in shellfish still need to be furtherly explored.The results of this paper have important theoretical significance for early warning technology monitoring DST in mariculture zone and guaranteeing the sustainable development of the shellfish farming industry and consumers health.