The role of the mobile phase in the resolution of racemic esters of aminoacids by normal phase high-performance liquid chromatography

1988 ◽  
Vol 25 (7) ◽  
pp. 636-638 ◽  
Author(s):  
J. N. Akanya ◽  
D. R. Taylor
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Normal Phase

Mobile phase compositions for ceramide III by normal phase high performance liquid chromatography

2004 ◽  
Vol 9 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Seung Pyo Hong ◽  
Chong Ho Lee ◽  
Se Kyung Kim ◽  
Hyun Shik Yun ◽  
Jung Heon Lee ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Normal Phase

scholarly journals Chiral Separation and Determination of Etoxazole Enantiomers in Vegetables by Normal-Phase and Reverse-Phase High Performance Liquid Chromatography

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3134
Author(s):  
Ping Zhang ◽  
Yuhan He ◽  
Sheng Wang ◽  
Dongmei Shi ◽  
Yangyang Xu ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Chiral Separation ◽  
Mobile Phase ◽  
High Performance ◽  
Normal Phase ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Normal Phase Hplc ◽  
Chiralpak Ic

The chiral separation of etoxazole enantiomers on Lux Cellulose-1, Lux Cellulose-3, Chiralpak IC, and Chiralpak AD chiral columns was carefully investigated by normal-phase high performance liquid chromatography and reverse-phase high performance liquid chromatography (HPLC). Hexane/isopropanol, hexane/n-butanol, methanol/water, and acetonitrile/water were used as mobile phase at a flow rate of 0.8 mL/min. The effects of chiral stationary phase, mobile phase component, mobile phase ratio, and temperature on etoxazole separation were also studied. Etoxazole enantiomers were baseline separated on Lux Cellulose-1, Chiralpak IC, and Chiralpak AD chiral columns, and partially separated on Lux Cellulose-3 chiral column under normal-phase HPLC. However, the complete separation on Lux Cellulose-1, Chiralpak IC, and partial separation on Chiralpak AD were obtained under reverse-phase HPLC. Normal-phase HPLC presented better resolution for etoxazole enantiomers than reverse-phase HPLC. Thermodynamic parameters, including ΔH and ΔS, were also calculated based on column temperature changes from 10 °C to 40 °C, and the maximum resolutions (Rs) were not always acquired at the lowest temperature. Furthermore, the optimized method was successfully applied to determine etoxazole enantiomers in cucumber, cabbage, tomato, and soil. The results of chiral separation efficiency of etoxazole enantiomers under normal-phase and reverse-phase HPLC were compared, and contribute to the comprehensive environmental risk assessment of etoxazole at the enantiomer level.

scholarly journals SEPARATION AND DETERMINATION OF THE R-ISOMER OF ETODOLAC IN A BULK DRUG SUBSTANCE BY NORMAL-PHASE LIQUID CHROMATOGRAPHY

2016 ◽  
Vol 9 (6) ◽  
pp. 327
Author(s):  
Appasaheb Bajirao Lawande
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Analytical Method ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Normal Phase ◽  
Limit Of Quantification ◽  
Bulk Drug

ABSTRACT Objective:  The objective of the this work is to develop and validate a novel, simple,rapid and reliable analytical method for separation and determination of R-isomer impurity in Etodolac bulk drug material by normal-phase high-performance liquid chromatography as per International Conference on Harmonization guidelines. Methods: The Etodolac R- isomer and S-isomer were separated on a Chiralcel OD-H (150 x 4.0 mm, 5 micron) column by using Ethanol : n-Hexane:Trifluoroacetic acid (50:50:0.1 v/v.) mobile phase with equipped detector at wavelength 225 nm and 25 °C column oven temperature. The resolution between R-isomer and S-isomer were more than two recorded on chromatogram. The specified method was developed and validated for various parameters like reproducibility, limit of detection, limit of quantification, linearity and range, robustness, solution stability and mobile phase stability according to the International Conference on Harmonization (ICH) guidelines.  Results: Linearity were found for Etodolac R-isomer over the concentration range of 600–6000 ng/ml, with the linear regression (Correlation coefficient R = 0.998) and proved to be robust. Limit of detection and limit of quantification of Etodolac R-isomer was found to be 200 and 600 ng/ml. The retention time of R-isomer was considered to be 2.8 min. The percentage recovery of Etodolac R-isomer has been ranged from 97.0 to 102.0 in bulk drug material sample. The proposed analytical method has been found to be suitable, precise,reliable and accurate for the separation and quantitative determination of Etodolac R-isomer in bulk drug sample.                                                                                                                   Conclusion: A novel, speedy, accurate, precise, reliable and rugged analytical method has been developed and validated for normal phase high performance liquid chromatography to determine R-isomer impurity in Etodolac bulk drugs material as per ICH guideline. Keywords: Etodolac, HPLC, Known Impurity. Normal Phase, Validation.

Analysis of organic impurities of besifloxacin hydrochloride by high performance liquid chromatography with isocratic and gradient elution.

2019 ◽  
Vol 16 ◽  
Author(s):  
Joanna Wittckind Manoel ◽  
Camila Ferrazza Alves Giordani ◽  
Livia Maronesi Bueno ◽  
Sarah Chagas Campanharo ◽  
Elfrides Eva Sherman Schapoval ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Gradient Elution ◽  
Pharmaceutical Product ◽  
Raw Material ◽  
Isocratic Elution ◽  
Organic Impurities ◽  
Elution Method

Introduction: Impurity analysis is an important step in the quality control of pharmaceutical ingredients and final product. Impurities can arise from drug synthesis or excipients and even at small concentrations may affect product efficacy and safety. In this work two methods using high performance liquid chromatography (HPLC) were developed and validated for the evaluation of besifloxacin and its impurity synthesis, with isocratic elution and another with gradient elution. Method: The analysis by HPLC in isocratic elution mode was performed using a cyano column maintained at 25 °C. The mobile phase was composed by 0.5% triethylamine (pH 3.0): acetonitrile (88:12 v/v) eluted at a flow rate of 1.0 ml/min with detection at 330 nm. The gradient elution method was carried out with the same column and mobile phase components only modifying the rate between organic and aqueous phase during analysis. The procedures have been validated according to internationally accepted guidelines, observing results within acceptable limits. Results: The methods presented were found to be linear in the 140 to 260 µg/ml range for besifloxacin and 0.3 to 2.3 µg/ml for an impurity named A. The limits of detection and quantification were respectively 0.07 and 0.3 µg/ml for impurity A, with a 20 µL injection volume. The precision achieved for all analyses performed provided RSD inter-day equal to 6.47 and 6.36% for impurity A with isocratic elution and gradient, respectively. The accuracy was higher than 99% and robustness exhibited satisfactory results. In the isocratic method an analysis time of 25 min and 15 min was obtained for gradient. For impurity A, the number of theoretical plates in the isocratic mode was about 5000 while in the gradient mode it was about 45000, hence, it made the column more efficient by changing the mobile phase composition during elution. In besifloxacin raw material and in pharmaceutical product used in this study, other related impurities were present but but impurity A was searched for and not detected Conclusion: The proposed methods can be applied for quantitative determination of impurities in the analysis of the besifloxacin raw material, as well as in ophthalmic suspension of the drug, considering the quantitation limit.

Separation and Determination of Some Aromatic Sulfones by Reversed-Phase High-Performance Liquid Chromatography

1994 ◽  
Vol 59 (3) ◽  
pp. 569-574 ◽  
Author(s):  
Josef Královský ◽  
Marta Kalhousová ◽  
Petr Šlosar
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Uv Spectra ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Technical Grade

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.

Sign in / Sign up

Export Citation Format

Share Document