RESUMEN
Water chestnut is one of the most popular vegetables in Asian countries that grows in shallow water. Eighteen water chestnut samples were collected from Lake Tai and six samples were bought at markets in Wuxi, China, in October 2007. Extraction solution of water chestnut was cleaned up with a solid phase extraction column and immunoaffinity chromatography cartridges, then the microcystin (MC) level was detected by indirect competitive enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-mass spectrometry (LC-MS). The results of ELISA showed that there were six samples collected from Lake Tai which contained MCs; the highest level of total MCs was 7.02 ng/g. The results of LC-MS confirmed that MC-LR and MC-RR were present in five samples. The highest level of MC-LR was 1.02 ng/g and that of MC-RR was 4.44 ng/g. Heavy cyanobacterial blooms had occurred, and MCs were detected in water at the points in Lake Tai where MCs occurred in water chestnuts collected in 2007. MCs were not detected in the six samples bought at Wuxi markets. The results suggest that MCs can accumulate in water chestnuts, which is a potential hazard for human health.
Asunto(s)
Cianobacterias/química , Eleocharis/química , Eutrofización , Microcistinas/análisis , Anticuerpos Monoclonales/química , Cromatografía Líquida de Alta Presión , Ensayo de Inmunoadsorción Enzimática , Espectrometría de Masas , Extractos Vegetales/análisisRESUMEN
Microcystin-LR (MC-LR) is a heptapeptide hepatotoxin produced by cyanobacteria. Immunoaffinity chromatography (IAC) column was prepared with CNBr-activated Sepharose 4B and monoclonal antibody of MC-LR. Water sample was cleaned up by IAC column and the content of MC-LR in water was determined by liquid chromatography-mass spectrometry (LC-MS). The results suggested that the IAC column exhibited highly selective specificity for MC-LR and selective removed interference from complex water sample. Water sample was concentrated for 2,000-fold through once purification. Cyanobacterial blooms had broken out in 2007 in Lake Tai, the third largest freshwater lake in China. Water samples from two parts of Lake Tai had been analyzed. The highest concentration of MC-LR in water from Lake Tai was 0.522 microg/L.