Determination of mephenytoin stereoselective oxidative metabolism in urine by chiral liquid chromatography employing β-cyclodextrin as a mobile phase additive

Author(s):  
K. Róna ◽  
I. Szabó
1994 ◽  
Vol 59 (3) ◽  
pp. 569-574 ◽  
Author(s):  
Josef Královský ◽  
Marta Kalhousová ◽  
Petr Šlosar

The reversed-phase high-performance liquid chromatography of some selected, industrially important aromatic sulfones has been investigated. The chromatographic behaviour of three groups of aromatic sulfones has been studied. The optimum conditions of separation and UV spectra of the sulfones and some of their hydroxy and benzyloxy derivatives are presented. The dependences of capacity factors vs methanol content in mobile phase are mentioned. The results obtained have been applied to the quantitative analysis of different technical-grade samples and isomer mixtures. For all the separation methods mentioned the concentration ranges of linear calibration curves have been determined.


2021 ◽  
Vol 66 (3) ◽  
pp. 172-176
Author(s):  
Lyubov Borisovna Kalikova ◽  
E. R. Boyko

Adenine nucleotides (ATP, ADP and AMP) play a central role in the regulation of metabolism and energy: they provide the energy balance of the cell, determine its redox state, act as allosteric effectors of a number of enzymes, modulate signaling and transcription factors and activate oxidation or biosynthesis substrates. A large number of methods have been developed to determine the level of ATP, ADP and AMP, but the most universal and effective method for the separation and analysis of complex mixtures is the reversed-phase high-performance liquid chromatography method (RP-HPLC). The aim of this study is to determine the optimal conditions for the qualitative separation and quantitative determination of standard solutions of ATP (1 mmol/l), ADP (0,5 mmol/l) and AMP (0,1 mmol/l) by RP-HPLC. The degree of separation of adenine nucleotides was estimated by the time of peak output in the chromatogram. To achieve the goal, the following tasks were set: assess the effect of the temperature of the analysis on the separation and change of the release time of the analytes in the chromatogram; determine the most optimal composition of the mobile phase for the separation of ATP, ADP and AMP in the chromatogram (the content of the organic solvent in the solution); to identify the effect of pH of the mobile phase on the separation of standard solutions of adenine nucleotides; set the optimal molarity of the mobile phase for the separation of ATP, ADP and AMP in the chromatogram. It was found that the temperature of the analysis does not affect the quality of peak separation, while the composition and pH of the mobile phase have a significant effect on the complete and clear separation of the studied nucleotides in the chromatogram. It was determined that the analysis temperature of 37°C and the mobile phase of 0.05 M KH2PO4 (pH 6.0) are optimal for separating the peaks of adenine nucleotides.


Author(s):  
Kishorkumar L. Mule

Objective: To develop and validate new, simple and rapid assay method for Prochlorperazine edisylate drug substance by UPLC as per ICH guidelines.Methods: Ultra performance liquid chromatographic method was developed, optimized and validated on Acquity UPLC by using Acquity BDH300 C4 (100 x 2.1 mm) 1.7µ column. 3.85g ammonium acetate in 1000 ml of water add 0.5 ml trifluoroacetic acid and 1 ml triethylamine (Mobile phase A): 0.5 ml trifluoroacetic acid in 1000 ml acetonitrile mobile phase (Mobile phase B) with gradient program. Detector wavelength 254 nm and column temperature 30 °C.Results: Linearity study was carried out for prochlorperazine edisylate, linearity was calculated from 80 % level to 120% with respect to specification level. The correlation coefficient (r) = 0.999 was proved that the method is robust. The resolution between known impurities and Prochlorperazine edisylate found more than 2.5, it was evident from specificity test that Prochlorperazine edisylate peak are well separated from its related impurities, hence the method is specific. Prochlorperazine edisylate sample solution and mobile phase were found to be stable for at least 3 d.Conclusion: A new, simple and rapid method has been developed and validated for assay determination of prochlorperazine edisylate in drug substance by Ultra Performance Liquid Chromatography (UPLC). The analytical method was developed and validated as per ICH guidelines. The developed method can be used for the fast assay determination of prochlorperazine edisylate drug substances in research laboratories and in the pharmaceutical industry. 


1999 ◽  
Vol 82 (6) ◽  
pp. 1308-1315 ◽  
Author(s):  
Francisco García Sánchez ◽  
Aurora Navas Díaz ◽  
Angeles García Pareja ◽  
Germán Cabrera Montiel

Abstract High-performance liquid chromatography using a combination of photometric, fluorimetric, and diode-laser polarimetric detectors in series for the determination of (+)-quinidine and (–)-quinine was investigated. An RP-8 reversed-phase column and methanol-water (80 + 20, v/v) with 0.2% triethylamine as mobile phase at a flow rate of 1 mL/min were used. A dynamic range of 0-200 μg for (+)-quinidine and (+)-quinine was established, with detection limits of 17.0 and 16.7 μg, respectively. An application of this method in spiked rabbit serum was developed.


Author(s):  
Muhammad Fawad Rasool ◽  
Umbreen Fatima Qureshi ◽  
Nazar Muhammad Ranjha ◽  
Imran Imran ◽  
Mouqadus Un Nisa ◽  
...  

AbstractTh accurate rapid, simple and selective reversed phase high performance liquid chromatography (RP-HPLC) has been established and validated for the determination of captopril (CAP). Chromatographic separation was accomplished using prepacked ODSI C18 column (250 mm × 4.6 mm with 5 μm particle size) in isocratic mode, with mobile phase consisting of water: acetonitrile (60:40 v/v), pH adjusted to 2.5 by using 85% orthophosphoric acid at a flow rate of 1 mL/min and UV detection was performed at 203 nm. RP-HPLC method used for the analysis of CAP in mobile phase and rabbit plasma was established and validated as per ICH-guidelines. It was carried out on a well-defined chromatographic peak of CAP was established with a retention time of 4.9 min and tailing factor of 1.871. The liquid–liquid extraction method was used for extraction of CAP from the plasma. Excellent linearity (R2 = 0.999) was shown over range 3.125–100 µg/mL with mean percentage recoveries ranges from 97 to 100.6%. Parameters of precision and accuracy of the developed method meet the established criteria. Intra and inter-day precision (% relative standard deviation) study was also performed which was less than 2% which indicate good reproducibility of the method. The limit of detection (LOD) and quantification for the CAP in plasma were 3.10 and 9.13 ng/mL respectively. The method was suitably validated and successfully applied to the determination of CAP in rabbit plasma samples.


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