Detection And Analysis On Paralytic Shellfish Toxins In Fujian Aquaculture Area

Paralytic shellfish toxins(PSTs)are the most widely distributed and harmful shellfish toxins in the world.The toxins can be accumulated by feeding toxic red-tide algae in shellfish and transformed to human-beings via food chain,causing poisoning incidents and even death.Fujian province is a big province of shellfish cultivation with a high incidence of harmful algae blooms(HABs).In recent years,paralytic shellfish toxins incidents have been outbreaking frequently in the coastal areas of Fujian province,but there were few reports on the related detection of paralytic shellfish toxins.In this study,numbers of shellfish samples were collected from the coastal areas of Fujian during 2017 to 2018,including oyster,mussel,sinonovacula constricta and clams.The systematic and comprehensive research of paralytic shellfish toxins in these samples were completed by mouse bioassay(MBA)and high performance liquid chromatography-tandem mass spectometry(HPLC-MS/MS).The study contents are as follows:1.Paralytic shellfish toxins from shellfish samples from Fujian aquaculture regions were investigated by MBA.Sixtenn batches of oystr were collected from the key monitoring regions,the detection rate of PST was 43.8%and the detection range was 124.3-1450.7 ?g/100g;For 19 batches of mussel samples,the detection rate was 84.2%and the detection range was 40.91-3434.4 ?g/100g;For 6 batches of razor clam samples,the detection rate was 0%;For 3 batches of clam samples was 0%.For 24 batches of oyster,24 batches of mussel,14 batches of razor clam,and 7 batches of clam samples in regular monitoring regions,the detection rate was 0%.The results showed that different shellfish samples had significant differences in the accumulation and digestion rate of PST.The impact of harmful algae blooms on mussel was greater than that of on oyster during the outbreak of Gymnodinium catenatum redtide in the coastal water of Fujian province in 2017;but there was no impact on razor clam and clam.The content of PST in shellfish was not necessarily related to the sampling seasons,but closely telated to the species and density of algae in the environment.2.HPLC-MS/MS method was established for the study of nine PSTs.Nine major PST toxins included STX,dcSTX,GTX1-5 and dcGTX2-3.The purification effect of C18 and HLB as well as the separateon effect of BEH-C18 and HILIC-A were compared.The experimental results showed that nine toxins had a good linear relationship with a concentration range of 10.0-200 ng/mL;the correlation coefficient R2 was greater than 0.9972;the average recovery was 78.9%-89.7%;the relative standard deviation(RSD)was between 1.5%-9.5%.This method could be used in the detection on paralytic shellfish toxins with good stability and repeatability.3.The HPLC-MS/MS detection results of paralytic shellfish toxin from shellfish samples from Fujian aquaculture regions.17 out of total 60 samples were found to be positive,and the detection range was 31.4?g/kg-759.0 ?g/kg;In those 17 positive samples,dcSTX detection rate was 100%,GTX1/4 detection rates were 29.4%,GTX2/3 detection rates were 11.8%,GTX5 detection rate was 23.5%,dcGTX2/3 detection rates were 17.6%,and STX had not been detected.The results showed that there were differences in shellfish components and contents among different regions in the aquaculture area in Fujian,but they were generaly similar.dcSTX was the principal components,GTX1-5 and dcGTX2-3 were the second,and STX had a lower proportion.The components of PSTs in different shellfish had little difference due to the similar aquaculture environment.