Exposed Features And Risk Assessment Of Lipophilic Shellfish Toxins And Heavy Metals In Shellfish

This study aims to establish an accurate and reliable high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for the simultaneous detection of 12 lipophilic shellfish toxins,and to understand the contamination status of lipophilic shellfish toxins in shellfish from Shenzhen and other coastal cities in Guangdong Province,to explore the exposure characteristics and compound exposure characteristics of heavy metals and lipophilic shellfish toxins in shellfish samples sold in Shenzhen in terms of time,shellfish species and origin,and to provide a theoretical basis for the risk monitoring system of heavy metals and lipophilic shellfish toxins in shellfish sold in Shenzhen.This study will provide a data base and theoretical basis for the risk monitoring system of heavy metals and lipophilic shellfish toxins in shellfish sold in Shenzhen.The first chapter of this article introduces the classification,physical and chemical properties and toxic effects of lipophilic shellfish toxins,the pollution of heavy metals in the ocean,the toxic effects of lipophilic shellfish toxins and heavy metals on shellfish.In the second chapter of this article,methanol was used to repeatedly extract lipophilic shellfish toxins,-80? freezing centrifugal filtration membrane to remove impurities,chromatographic conditions and mass spectrometry conditions were optimized,and a LC-MS/MS detection method for simultaneous detection of 12 lipophilic shellfish toxins(OA,DTX1,DTX2,h YTX,YTX,GYM,AZA1,AZA2,AZA3,SPX1,PTX2,Pn TX)was established.The detection limit in shellfish is0.3 ?g/kg?1 ?g/kg,the quantification limit is 1 ?g/kg?3 ?g/kg,the average recovery rate is between 79.2%?126%,and the relative standard deviation is 1.08% ?11.8%,the analysis results applied to the quality control of standard reference materials are all within the reference range.360 shellfish samples from 12 coastal cities in Guangdong Province were tested in July 2018,July 2019,and July2020,and six types of lipophilic shellfish were detected: YTX,h YTX,GYM,AZA1,AZA2 and SPX1 Toxins.In chapter 3 of this paper,550 samples of shellfish sold in Shenzhen City from July to December 2020 were tested for lipophilic shellfish toxins and heavy metals,and fourteen heavy metals and eleven LSTs were detected.heavy metal content was significantly different among shellfish species(P<0.05),and Cr,Cu,Zn,Cd and Pb were exceeded;the detection rate of LSTs was 57.2%,and there was no exceedance.The detection rates of h YTX and GYM were 31.51% and31.59%.The detection rates of LSTs ranged from 33% to 76% and from 1 ?g/kg to 422 ?g/kg in different origins.For the temporal distribution of the LSTs showed an overall trend of gradually decreasing in summer and autumn and increasing in autumn and winter.For correlation analysis,most heavy metals were significantly correlated with each other(P<0.05);h YTX was positively correlated with GYM and SPX1 concentrations(P<0.05);YTX was positively correlated with PTX2 concentration(P<0.05)and negatively correlated with GYM concentration(P<0.05);heavy metals Sn was positively correlated with GYM,Cr and SPX1 concentrations(P<0.05),and Mn was negatively correlated with PTX2 concentration(P<0.05).