Quantitative Determination of Microcystins in Rat Plasma by LC-ESI Tandem MS

A rapid and sensitive method was developed and validated for the determination of MCYST (microcystin)-RR, -LR, and [Dha(7)] MCYST-LR in rat plasma by liquid chromatography-tandem mass spectrometry. The analytes were extracted from rat plasma by protein precipitation, followed by solid-phase extraction. Liquid chromatography with electrospray ionization mass spectrometry, operating in selected reaction monitoring (SRM) mode, was used to quantify MCYST-RR, -LR, and [Dha(7)] MCYST-LR in rat plasma. The recoveries for each analyte in rat plasma ranged from 70.8 to 88.7%. The calibration curve was linear within the range from 0.005 to 1.25 mu g mL(-1). The limit of detection were 1.4, 1.0, 0.6 ng mL(-1) for MCYST-RR, -LR, and [Dha(7)] MCYST-LR. The overall precision was determined on three different days. The values for within- and between-day precision in rat plasma were within 15%. This method was applied to the identification and quantification of microcystins in rat plasma with acute exposure of microcystins via intravenous injection.