Teicoplanínová a vancomycínová kolóna sa použila na separáciu niektorých dansyl derivátov α-aminokyselín. Navrhli sa separačné mechanizmy separácie chirálnych látok na základe nameraných chromatografických údajov použitím rôznych kolón. Skúmali sa interakcie medzi molekulami separovaných látok a stacionárnou fázou.
Teicoplanin and vancomycin columns were used for the separation of some dansyl derivates of α-amino acids. By comparison of chromatographic data which were measured in various column it is possible to propose the separation mechanisms of chiral compounds. The interaction between molecules of compound of interest and the stationary phase was investigated.
A novel and sensitive derivatization procedure for the determination of 2-cynaoacetamide in pharmaceutical samples using liquid chromatography with the fluorescence detection was discovered. The method is based on derivatization of 2-cynaoacetamide using 2-hydroxyacetophenone as a new derivatization reagent. The product of derivatization reaction was isolated and characterized using spectroscopic techniques namely LC-MS, NMR and IR. The structure of 2-cyanoacetamide derivative was unambiguously assigned as a 2-amino-4-phenylfuran-3-carboxamide. Two derivatization systems were optimized in terms of reaction temperature, reaction time, pH and concentration of 2-hydroxyacetophenone, and a new pre- and post-derivatization HPLC methods were developed. The separations on HPLC with pre-column derivatization were accomplished using stationary phase based on a XBridge C18 column (100×4.6, 3.5μm) and isocratic elution using the mobile phase acetonitrile - 0.1% formic acid (30:70, v/v). The separations on the HPLC with post-column derivatization were performed on stationary phase on a TSKgel Amide-80 column (150×4.6mm, 3μm). The mobile phase was a mixture of acetonitrile, methanol and 10mM sodium formate buffer at pH=4.5 in ratio 3:2:95 (v/v). Both HPLC methods were fully validated in terms of linearity, sensitivity (limit of detection and limit of quantification), accuracy and precision according to ICH guidelines. The pre-column derivatization method was linear in the range 1.1-2000μg/l with method accuracy≥98.2% and method precision RSD≤4.8%. The post-column derivatization method was linear in the range 12-2000μg/l. Method accuracy≥96.3% and method precision RSD≤3.5%. Proposed new methods were proved to be highly sensitive, simple and rapid, and were successfully applied to the determinations of 2-cynaoacetamide in pregabalin.
- MeSH
- Acetophenones chemistry MeSH
- Mass Spectrometry MeSH
- Indicators and Reagents * MeSH
- Magnetic Resonance Spectroscopy MeSH
- Nitriles analysis MeSH
- Pregabalin chemistry MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Chromatography, High Pressure Liquid methods MeSH
- Publication type
- Journal Article MeSH
- Validation Study MeSH
o-Phthaldialdehyde was used in combination with a series of six thiosugars for the pre-column chiral derivatization of selected primary amino acids. The diastereomers were resolved on a conventional reversed-phase column and with fluorescence detection. A surprisingly effective resolution of 1-isoindolyl-(1-thioglycosides) derived from 1-thio-beta-L-fucose was observed.
1795 s.
- Conspectus
- Biochemie. Molekulární biologie. Biofyzika
- NML Fields
- biochemie
298 s.
- Conspectus
- Biotechnologie. Genetické inženýrství
- NML Fields
- biomedicínské inženýrství
A differential pulse polarographic (DPP) method has been developed for the determination of ascorbic acid (AA) and dehydroascorbic acid (DHA), the two main forms of Vitamin C. The method consists of the DPP analysis of a quinoxaline obtained by the derivatization of DHA with o-phenylenediamine. Results using the proposed method correlated well with those obtained by two reference methodologies: the common iodometric method and a published chromatographic methodology. It was also used in the study of Vitamin C degradation in fruit juices, showing that it involves an initial oxidation of AA to DHA, followed by hydrolytic degradation of the latter.
