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(68-04) Determination of microcystins in surface water by HPLC-MS/MS. DeBlois, Christian*,1, Laverdiere, Annie1, Houde, Francois1, Tremblay, Hélène2, Dassylva, Nathalie1, 1 Ministère de l'Environnement du Québec, Ste-Foy, Québec, Canada2 Ministère de l'Environnement du Québec, Québec, Qyébec, Canada ABSTRACT- Surface water temperature increase significantly in southern Canada during summer season, as well as the duration of the day, which leads to ideal conditions for algae blooms. These blooms appear from the beginning of June, and depending of the meteorological conditions, they can persist until October. They are caused by blue-green algae, amongst others, called cyanobacterias. These cyanobacterias release toxins in the water, such as microcystins and anatoxin-A. The presence of microcystin-LR, -RR, -YR and anatoxin-A was determined with a liquid chromatograph coupled to a tandem mass spectrometer (LC-MS/MS). Surface water where algae-blooms were observed during the last few years were monitored for toxins concentrations during the summer and autumn of 2001. Intracellular toxins concentrations were also determined for evaluation of the maximum quantity of toxins that can potentially be liberated by the cells. Some of the lakes monitored are used as drinking water treatment plants sources. For this reason, drinking water generated by these plants were also screened for toxins contamination. None of the measured concentrations of microcystin-LR in drinking water was over the Canadian provisional maximum acceptable concentration of 1.5 Key words: microcystin, anatoxin, hplc-ms/ms, cyanobacteria |
g/L. The measured concentrations in surface water were from < 0.005 to 210