Separation of tamsulosin enantiomers by capillary electrophoresis with tandem mass spectrometry and online stacking preconcentration

The aim of our work was to develop a new method for the analysis of tamsulosin enantiomers by capillary electrophoresis connected with tandem mass spectrometry. The pharmacologically active (R)-enantiomer of tamsulosin, is used to treat benign prostatic hyperplasia and chronic prostatitis. Under the optimal conditions, background electrolyte consisting of 200 mM acetic acid titrated with NH₄OH to pH 4.0 containing 4.0 mg mL^-1 sulfated β-cyclodextrin, an injection time of 40 s at 50 mbar, a voltage of 20 kV and an optimized MS set-up (as e.g., sheath liquid containing 75 : 24.9 : 0.1 MeOH, H₂O, and formic acid, v/v), a limit of detection of 1.6 nmol L^-1 was achieved. The method was validated in terms of linearity, detection and quantification limits, precision, recovery, and selectivity. The results showed that the method can be used for the analysis of tamsulosin enantiomers in environmental samples, but generally, it can be applied to many different analytical tasks.