scholarly journals The Use of Water Structure Breakers, Urea and Guanidium Chloride, New Mobile Phase Modifiers in Reversed-phase Partition High-Performance Liquid Chromatography

2001 ◽  
Vol 17 (7) ◽  
pp. 847-851 ◽  
Author(s):  
Toru TAKAHASHI ◽  
Hitoshi HOSHINO ◽  
Takao YOTSUYANAGI
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.


1977 ◽  
Vol 23 (12) ◽  
pp. 2288-2291 ◽  
Author(s):  
P H Culbreth ◽  
I W Duncan ◽  
C A Burtis

Abstract We used paired-ion high-performance liquid chromatography to determine the 4-nitrophenol content of 4-nitrophenyl phosphate, a substrate for alkaline phosphatase analysis. This was done on a reversed-phase column with a mobile phase of methanol/water, 45/55 by vol, containing 3 ml of tetrabutylammonium phosphate reagent per 200 ml of solvent. At a flow rate of 1 ml/min, 4-nitrophenol was eluted at 9 min and monitored at 404 nm; 4-nitrophenyl phosphate was eluted at 5 min and could be monitored at 311 nm. Samples of 4-nitrophenyl phosphate obtained from several sources contained 0.3 to 7.8 mole of 4-nitrophenol per mole of 4-nitrophenyl phosphate.


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.


Author(s):  
Mannem Durga Babu ◽  
Kesana Surendrababu

Objective: The objective of the study was to develop and validate a novel, specific, precise, and simple reversed-phase high-performance liquid chromatography method for the estimation of guaifenesin present in methocarbamol API and its pharmaceutical dosage forms. Methods: The baseline separation for methocarbamol and guaifenesin was achieved by utilizing a Inertsil ODS C18 (250 mm × 4.6 mm) 5 μm column particle size and an isocratic elution method. The mobile phase contains a mixture of water and acetonitrile in the ratio of 70:30 v/v, respectively. The flow rate of the mobile phase was 1.0 mL/min with a column temperature of 25°C and detection wavelength at 272 nm. The method was validated for a limit of detection (LOD), limit of quantification (LOQ), linearity, accuracy, and reproducibility with the help of the exhibit and simulated samples. Results: The LOD for guaifenesin was 0.62 μg/mL. The LOQ for guaifenesin was 1.87 μg/mL. The correlation coefficient obtained for impurity was >0.99. The recovery was obtained for impurity was 106.56% at 50%, 95.20% at 100%, and 100.45% at 150%. In tablet analysis, we can found 0.26% (<0.5%). Conclusion: The developed method was validated as per the ICH guidelines with respect to specificity, precision, linearity, accuracy, LOD and quantification, ruggedness, robustness, and solution stability.


Author(s):  
M. I. UVAROVA ◽  
G. D. BRYKINA ◽  
O. A. SHPIGUN

In this work the influence of the porphyrin structure and of the nature of the mobile phase upon retention parameters is examined by means of reversed phase high-performance liquid chromatography (HPLC). Acetonitrile–ethyl acetate and other mixtures were used as eluents. An increase in the retention of azo- and benzosubstituted porphyrins as well as of those containing a large number of carbon atoms as substituents of macrocycles may be noted. A variation in the polarity of the mobile phase affects the retention of the ligands more than that of their zinc complexes. The retention of the most hydrophobic compounds may be well described in coordinates lg k'– lg M. For less hydrophobic porphyrins these dependences are close to linear only within limited intervals of mobile phase ethyl acetate concentration. The best separation of zinc complexes was achieved with acetonitrile as the eluent. The detection limit of porphyrin ligands and complexes with metals is n × 10-8 M.


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