Tag Archives: capillary electrophoresis

Determination of HMG-CoA reductase inhibitors by micellar electrokinetic chromatography

DOI: 10.1515/amma-2016-0006

Objective: In this study we report the development of a simple, rapid and efficient capillary electrophoresis method for the simultaneous determination of atorvastatin, fluvastatin, lovastatin and simvastin.
Methods: Capillary zone electrophoresis proved to be efficient for the simultaneous separation of atorvastatin and fluvastatin, but could not resolve the determination of lovastatin and simvastatin. The simultaneous separation of all four statins was achieved by applying a micellar electrokinetic chromatographic method, after transforming lovastatin and simvastatin in β-hydroxyl acid forms through alkaline hydrolysis. The optimum electrophoretic conditions and analytical parameters were investigated and the analytical performances of the method were verified with regard to linearity, precision, accuracy, LOD and LOQ.
Results: The optimum electrophoretic separation conditions were: 25 mM sodium tetraborate with 25 mM sodium dodecyl sulphate buffer electrolyte at pH 9.5, applied voltage + 25 kV, separation temperature 25 °C, injection pressure/time 50 mbar/1 minutes, UV detection at 230 nm. Using the optimized electrophoretic conditions we succeeded in the simultaneous determination of the four statins in approximately 3 minutes, the order of migration being: atorvastatin, fluvastatin, lovastatin, simvastatin. The proposed method has been applied to the determination of the analytes in pharmaceutical tablets formulations.
Conclusions: The capillary electrophoretic method developed in the present work proved to be suitable for the routine analysis of statins and can be adopted as quality control protocol in pharmaceutical analysis.

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Capillary Electrophoresis in the Analysis of Polyunsaturated Fatty Acids

DOI: 10.1515/amma-2015-0103

The aim of this study to inventory the main electrophoretic methods for identification and quantitative determination of fatty acids from different biological matrices. Critical analysis of electrophoretic methods reported in the literature show that the determination of polyunsaturated fatty acids can be made by: capillary zone electrophoresis, micellar electrokinetic chromatography and microemulsion electrokinetic chromatography using different detection systems such as ultraviolet diode array detection, laser induced fluorescence or mass – spectrometry. Capillary electrophoresis is a fast, low-cost technique used for polyunsaturated fatty acids analysis although their determination is mostly based on gas chromatography.

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Optimization of a Capillary Electrophoresis Method for the Separation of Quinolone Derivatives

Background: In this work the applicability of capillary zone electrophoresis for the separation of quinolones from different generations has been studied.
Objective: Our aim was to develop a capillary electrophoretic method for the simultaneous separation of four quinolones and also to optimize the analytical conditions.
Material and methods: Capillary electrophoresis (CE) is a family of related techniques that use narrow-bore fused-silica capillaries to perform high efficiency separations of both small and large molecules. For this we chose four quinolones: a naftiridine derivate (nalidixic acid), a pyrido-pyrimidine derivate (pipemidic acid) and two second generation fluoroquinolones with different structures (ciprofloxacin, ofloxacin).
Results: A fast and reliable method has been developed, using a separation buffer composed of 40 mM natrium tetraborate and 5% methanol as organic modifier, with whom we achieved the separation of the studied quinolones in less than 10 minutes.
Conclusions: CE proved to be an efficient tool in the separation of quinolones from different generations.

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Development of a Separation Method of Four Penicillin Derivatives by Capillary Electrophoresis

Introduction: The objective of this paper is the development and optimization of a capillary electrophoresis method, which allows the separation of four frequently used penicillin derivatives (amoxicillin, ampicillin, benzilpenicillin and oxacillin), with possible application in the analysis of environmental samples.
Material and method: In our experiments we worked on water solutions of the studied penicillins. The analysis was performed on an Agilent Capillary Electrophoresis System with a diode array detector. The data were recorded and processed by Chemstation software.
Results: Different buffer solutions were tried out in order to reach the most efficient separation of the studied compounds. The influence of different analytical parameters was evaluated by varying the buffer concentration, buffer pH, voltage, temperature, injection time and pressure. The analytical performance of the method was verified, in order to estimate reproducibility and sensitivity.
Conclusions: A micellar electrokinetic capillary chromatography method has been developed for the separation of the four penicillins. We obtained the best results with a buffer solution containing 25 mM sodium tetraborate and 100 mM sodium dodecyl sulfate (pH = 9.3), the separation being achieved in approximately 5 minutes.

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Separation by Capillary Electrophoresis of Six Extensively Used Antibacterial Compounds

Background: Penicillins and fluoroquinolones are two of the most extensively utilized class of antibacterial substances. Taking into account the importance of these compounds in the human and veterinary antibacterial therapy, identification and separation of these compounds in different complex matrices represent a necessity and also a challenge.
Objective: The aim of our study was to elaborate an alternative separation technique, suitable for the identification and separation of four penicillin derivatives – amoxicillin, ampicillin, benzylpenicillin and oxacillin – and two fluoroquinolones: ciprofloxacin and norfloxacin, and to optimize the analytical conditions.
Material and methods: MEKC proved to be the appropriate method of analysis for the separation of the studied compounds. The CE experiments were conducted on the Agilent 6100 CE System; the data were recorded and processed with Agilent Chemstation software.
Results: An optimum separation was achieved using a buffer solution containing 25 mM sodium tetraborate, 100 mM sodium dodecyl sulfate and 100 mM boric acid. The migration order of the six compounds was: amoxicillin, ampicillin, benzylpenicillin, oxacillin, ciprofloxacin and norfloxacin. The analytical performance of the method was evaluated by calculating the standard deviation for the peak area and also by checking the linearity of the determination.
Conclusions: The proposed method proved to be an efficient and useful tool in the separation of the studied substances and can find useful applications in the analysis of the studied substances from environmental samples.

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Study of Cyclodextrin/Fluoroquinolone Inclusion Complexes by Capillary Electrophoresis

DOI: 10.2478/amma-2013-0026

Introduction: In the present work we evaluated the complexation role of cyclodextrins toward fluoroquinolones in an attempt to assess their potential as new formulation additives for more efficient fluoroquinolone delivery and as selectors in capillary electrophoresis.
Material and method: Guest-host interactions of two second generation quinolones, ciprofloxacin and norfloxacin with four cyclodextrins, beta-cyclodextrin (β-CD), gamma-cyclodextrin (γ-CD) and two beta-cyclodextrin derivatives, 2-hydroxypropyl beta-cyclodextrin (HP-β-CD) and randomly methylated beta-cyclodextrin (RAMEB), were tested by capillary electrophoresis in borate running buffer. Experimental parameters like buffer concentration, pH, organic modifier, voltage and cyclodextrin concentration have been varied for a better resolution.
Results: In capillary zone electrophoresis ciprofloxacin and norfloxacin are migrating together, a difference in their migration times and thus separation occured by the addition of cyclodextrins.
Conclusion: Our results suggest formation of inclusion complexes between fluoroquinolones and cyclodextrins. Differences in their affinity to host molecules resulted in separation of the two fluoroquinolones.

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