| dc.description.abstract | Overbreeding of aquatic plants and algae not only causes deterioration of water quality, but some species of algae also produce toxins, one of the most commonly found being microcystin. Microcystin is toxic to the liver and nervous system, and also promotes tumor growth, with microcystin-LR (MC-LR) being the most prevalent and most toxic out of all the isoforms possible. In addition to the hidden dangers of exposure to environmental microcystin in water, humans may also come into contact with microcystin through our foods, as the toxin accumulates via the food chain.
In this study, a solid phase extraction (SPE) method coupled with thiol derivation and matrix-assisted laser desorption/ ionization time of flight mass spectrometry (MALDI-TOF MS) was developed, and was able to successfully detect microcystins in water. The best experimental conditions included water sample at a flow rate of 1 mL / min, washing with 10% methanol (in water), and elution with 5 mL methanol for SPE (Supelclean ENVI-18). The eluent was dried under nitrogen and reconstituted with β-mercaptoethanol to derivatize the analyte.
In this study, the linear ranges of MC-LR and MC-YR were 0.5-10 μg/L, with coefficients of determination (r2) of 0.9939 and 0.9876, respectively. Limit of detection (LOD) was 0.2 μg/L. The method had good accuracy (recovery 93-116%) and precision (RSD < 9%). The concentrations of microcystin-LR and microcystin-YR in water samples were lower than the limits of detection. | en_US |