Abstract:

Objective A method was established for simultaneous determination of microcystins （microcystin-LR，-RR，-YR） in source water using high-performance liquid chromatography （HPLC）. Methods Water samples （500 mL） were filtered through a 0.45 μm membrane on a C18 column，then eluted with sequential use of 10 ml of ultra-pure water，20 mL of 20% methanol and 15 mL of 80% methanol containing 0.05% tallow fatty acid（TFA）. The eluate was dried and the residues were dissolved in 1 mL of ultra-pure water for testing. The eluate was fractionated on a C18  column with a mobile phase of 0.1% aqueous phosphoric acid-acetonitrile （67：33） at a flow rate of 1 ml/min at a column temperature of 45 ℃. Compounds were detected with a UV detector at a wavelength of 238 nm. Results Microcystin-LR，-RR，and -YR showed good peak shape and good linearity in the range of 0.05-1.0 μg/mL（r=0.9987， 0.9992，and 0.9997）. Recoveries ranged from 80% to 110%，relative standard deviation（RSD） was 5.0%-9.6%，and limits of detection were 0.028，0.037，and 0.056 μg/L. Conclusions The method described here can be used for accurate，highly sensitive，and reproducible simultaneous detection of microcystin-LR，-RR and -YR in source water.

Key words: Source water, Microcystins, High performance liquid chromatography, Water eutrophication