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A fast determination of yohimbine in pharmaceuticals by micellar electrokinetic chromatography

100%

Vítková K., Pechová M., Petr J., Znaleziona J., Ranc V., Maier V., Ševčík J.

Open Chemistry

2010

vol. 8

issue 2

273-277

A method for the fast determination of yohimbine, a potent adrenoreceptor antagonist used for the treatment of sexual dysfunctions, is proposed in this article. MEKC under basic and acidic conditions (sodium borate, pH 9.5 and sodium phosphate, pH 2.5) with SDS was developed. The effect of the experimental parameters, e.g. pH, SDS concentration and injection time, on yohimbine migration was also studied. Both methods were validated in terms of linearity, limits of detection and quantification, accuracy, and precision using caffeine as an internal standard. The application for the determination of yohimbine in hand-made medicaments is also investigated in this study. [...]

Separation of ketoprofen enantiomers at nanomolar concentration levels by micellar electrokinetic chromatography with on-line electrokinetic preconcentration

100%

Petr J., Ginterová P., Znaleziona J., Knob R., Lošťáková M., Maier V., Ševčík J.

Open Chemistry

2013

vol. 11

issue 3

335-340

Abstract Separation of enantiomers represents an extremely important task in the field of analytical chemistry. This paper contributes to the field of the on-line preconcentration of enantiomers by developing a novel setup based on the electrokinetic accumulation of ketoprofen enantiomers on the pH boundary followed by enantioselective mobilization by a mixture of SDS, sulfated-β-cyclodextrin (S-β-CD), and trimethyl-β-cyclodextrin (TM-β-CD). Under the best conditions, where the injection electrolyte was composed of 50 mmol L−1 borate/NaOH pH 9.5 with 60% (v/v) methanol, the background electrolyte contained 50 mmol L−1 phosphate/NaOH pH 2.5, and the mobilization electrolyte consisted of 50 mmol L−1 phosphate/NaOH pH 2.5 with 4.0% (w/v) S-β-CD, 0.5% (w/v) TM-β-CD, and 20 mmol L−1 SDS, the determination of nanomolar concentration levels of ketoprofen enantiomers was successful by using micellar electrokinetic chromatography with a common UV detection. LODs were 2.5 nmol L−1 and 3.4 nmol L−1, which represent enhancement factors of 9921 and 8529, respectively. The method was also applied to the determination of ketoprofen enantiomers in waste water samples by using simple filtration as a clean-up step. Here, the recovery of ketoprofen enantiomers was 91% at the concentration level of 5×10−9 mol L−1. Graphical abstract [...]

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2 Open Chemistry

1 2013

1 2010

2 Maier V.

2 Petr J.

2 Znaleziona J.

2 Ševčík J.

1 Ginterová P.

1 Knob R.

1 Lošťáková M.

1 Pechová M.

1 Ranc V.

1 Vítková K.

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A fast determination of yohimbine in pharmaceuticals by micellar electrokinetic chromatography

Separation of ketoprofen enantiomers at nanomolar concentration levels by micellar electrokinetic chromatography with on-line electrokinetic preconcentration