HPLC Separation of Diazepam Conformers Coupled with Off‐Line NMR Experiment
| Autor: | Andrea Fedurcová, Jozef Čižmárik, Nada Prónayová, Tibor Liptaj, Jozef Lehotay |
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| Rok vydání: | 2006 |
| Předmět: |
chemistry.chemical_classification
Chromatography Cyclodextrin Elution Clinical Biochemistry Analytical chemistry Pharmaceutical Science Reversed-phase chromatography Atmospheric temperature range Biochemistry High-performance liquid chromatography Analytical Chemistry chemistry Ionic strength Phase (matter) Conformational isomerism |
| Zdroj: | Journal of Liquid Chromatography & Related Technologies. 29:1351-1368 |
| ISSN: | 1520-572X 1082-6076 |
| Popis: | The HPLC analysis of diazepam conformers was carried out in the temperature range 273–313 K, increment 10 K. The pH of the mobile phase was 3.3; 5.5; 5.5 (Ic=const; 6.5; 6.5 Ic=const.). The various flow rates of 0.2; 0.5; 1.0; mL/min were used. Chiral stationary phase based on β‐cyclodextrin (ChiraDex) was used for separation of diazepam. The influence of temperature, flow rate, pH of mobile phase, and ionic strength on the retention and elution profile on two peaks of diazepam conformers were studied. After that, the chiral β‐cyclodextrin (0.001 mol/L; 0.003 mol/L; 0.005 mol/L) was added into the mobile phase. The increasing amount of β‐cyclodextrin in the mobile phase caused the disappearance of the first peak. The complete chiral separation of diazepam was not possible because of simultaneous interconversion. The plateau between two peaks of diazepam appeared in the whole range studied, any inhibitory effects of chromatographic conditions (pH of mobile phase, temperature, flow rate, ionic stre... |
| Databáze: | OpenAIRE |
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