Novel MEKC method for determination of sodium 2-mercaptoethanesulfonate in human plasma with in-capillary derivatization and UV detection

•Simple, cheap and fast MEKC assay for total mesna in human plasma was elaborated.•For the first time CMLT as an effective derivatization reagent in CE was used.•In-capillary derivatization of mesna with CMLT was applied.•Stacking with high salt concentration in MEKC was successfully employed.•The method exploits cheap and user friendly UV detection.

Sensitive electrophoretic method for determination of total sodium 2-mercaptoethanesulfonate (mesna) in human plasma, based on the stacking with high salt concentration in MEKC and in-capillary derivatization with 2-chloro-1-methyllepidinium tetrafluoroborate followed by UV detection was developed. In the method 0.03 mol L−1 pH 7 phosphate buffer with the addition of 0.01 mol L−1 SDS, and 10% ACN was used as a BGE. The limit of quantification (LOQ) of the method was 0.5 μmol L−1. Linearity in detector response was observed over the range of 0.5–10 μmol L−1 with the correlation coefficient 0.9971. The intra- and inter-day accuracy (three concentration levels, 5 days, n = 3) of the method ranged from 97.2 to 110.0% and from 94.0 to 101.2%, respectively. The novel MEKC method with UV detection proved to be suitable for determination of total mesna in human plasma.