A simple high-performance liquid chromatographic method for the measurement of 2-methylsulfonylpyridine in plasma

A simple and sensitive high-performance liquid chromatographic (HPLC) method for the analysis of 2-methylsulfonylpyridine (2-MSP) in plasma has been developed. Up to 1 mL of plasma containing 2-MSP and an internal standard was extracted with 3 mL of methylene chloride, usually twice, evaporated to dryness, resuspended in mobile phase, and chromatographed on two 15-cm C8 reversed-phase LC columns in series. The mobile phase was 5% acetonitrile in water with a flow rate of 1 mL/min and ultraviolet detection was at 260 nm. Extraction of plasma produced no interfering endogenous components and the recovery of 2-MSP was 60-70%. The intraday and interday statistics of 2-MSP standard curves from 10 to 320 ng in plasma demonstrate that the assay is sensitive and precise using either human or monkey plasma and any plasma volume up to 1 mL.