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.