Identification and determination of microcystins in source water and waterbloom sample from Meiliang Bay, Taihu Lake, China.

To identify and determine the congener and level of microcystins in the source water of Taihu Lake. Improved method of SPE combined with HPLC was employed to detect the concentration and varieties of microcystins in source water and bloom samples collected from Meiliang Bay, Taihu Lake. The contents of two predominant microcystin components, MC-RR, and MC-LR, were relatively high in samples during warm months and correlated with the phase of algae growth. The maximum concentrations of MC-RR and MC-LR in water sample reached 3.09 +/- 0.53 microg/L and 2.39 +/- 0.41 microg/L during the period of water bloom in September 2004, respectively. Even without waterbloom, the concentration of MC-LR in source water sample was still higher than the guideline value. The status of microcystin pollution in this region is serious and measures to monitor and control the growth of cyanobacteria are urgently needed.