Rebirth of recycling liquid chromatography with modern chromatographic columns : extension to gradient elution

2021 ◽  
pp. 462424
Author(s):  
Fabrice Gritti
2019 ◽  
Vol 15 (5) ◽  
pp. 505-510
Author(s):  
Yanjuan Zheng ◽  
Qiushi Peng ◽  
Rui Dong ◽  
Tingyu Chen ◽  
Yi Bao ◽  
...  

Introduction: A rapid, and accurate Ultra Performance Liquid Chromatography (UPLC) method was developed to simultaneously analyze Methocarbamol, Paracetamol and the related substances Materials and Methods: Waters ACQUITY UPLC® BEH Phenyl C18 column was used in conjunction with UV detection at 225nm. Gradient elution with 0.05M, pH 6 phosphate buffer and acetonitrile flow at 0.3mL /min rate were used to separate the substances. The retention times for 4-Aminopheno, Paracetamol, Guaifenesin, Methocarbamol, and 4-Chloroacetanilide were 1.319 minute, 2.224 minute, 4.467 minute, 4.769 minute and 5.433 minute respectively. The concentration was linear in the range of 2-100 µg/ml for Methocarbamol, and 1-100 µg/mL for Paracetamol. The percentage recoveries were between 99.28±1.23% to 100.57±0.99% for Methocarbamol, and between 99.08±1.23% to 101.23±1.39% for Paracetamol. Results and Discussion: The validated optimal protocol is robust and accurate for simultaneous analysis of Methocarbamol, Paracetamol and the related substances, applicable for bulk powder as well as pharmaceutical formulation. Conclusion: In this paper, a highly sensitive, accurate, and precise UPLC method with UV-Vis detection was developed and validated for quality control of MET and PAR in bulk as well as in pharmaceutical preparations.


2019 ◽  
Vol 16 ◽  
Author(s):  
Joanna Wittckind Manoel ◽  
Camila Ferrazza Alves Giordani ◽  
Livia Maronesi Bueno ◽  
Sarah Chagas Campanharo ◽  
Elfrides Eva Sherman Schapoval ◽  
...  

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.


2019 ◽  
Vol 15 (2) ◽  
pp. 130-137
Author(s):  
Hui Jiang ◽  
Lianhao Fu ◽  
Yu Wang ◽  
Shaozhi Wang ◽  
Xiaoxu Zhang ◽  
...  

Background: Jingzhiguanxin (JZGX) tablet, a traditional Chinese prescription, is commonly used for treating coronary heart disease and angina pectoris in the clinic. There are six active components (Danshensu (DSS), Protocatechuic aldehyde (PD), Paeoniflorin (PF), Ferulic acid (FA), Salvianolic acid B (Sal B) and Tanshinone IIA (TA)) in JZGX tablet. </P><P> Objective: In this paper, a simple and reliable method was used for simultaneous determining the six active components by high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). Methods: These six active components were separated on an Agilent Zorbax Eclipse XDB-C18 column (150 mmx4.6 mm, 5 µm) at 30 °C. Acetonitrile (A), methanol (B) and 0.5% H3PO4 aqueous solution (C) were used as mobile phase for gradient elution. The flow rate was 1 mL/min and the detection wavelengths were set at 280 nm for DSS, PD and Sal B, 230 nm for PF, 320 nm for FA and 270 nm for TA, respectively. Results: All of the six components showed good linearity regressions (r2≥0.9997) in the detected concentration range. The recovery rates and coefficient of variation (CV) for all analytes were 98.66%- 100.18% and 0.75%-1.89%, respectively. This method was successfully applied to simultaneously determine the six components in JZGX tablet from different batches and manufacturers. Conclusion: The validated method can be used in routine quality control analysis of JZGX tablet without any interference.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2123
Author(s):  
Luboš Fical ◽  
Maria Khalikova ◽  
Hana Kočová Vlčková ◽  
Ivona Lhotská ◽  
Zuzana Hadysová ◽  
...  

Two new ultra-high performance liquid chromatography (UHPLC) methods for analyzing 21 selected antivirals and their metabolites were optimized, including sample preparation step, LC separation conditions, and tandem mass spectrometry detection. Micro-solid phase extraction in pipette tips was used to extract antivirals from the biological material of Hanks balanced salt medium of pH 7.4 and 6.5. These media were used in experiments to evaluate the membrane transport of antiviral drugs. Challenging diversity of physicochemical properties was overcome using combined sorbent composed of C18 and ion exchange moiety, which finally allowed to cover the whole range of tested antivirals. For separation, reversed-phase (RP) chromatography and hydrophilic interaction liquid chromatography (HILIC), were optimized using extensive screening of stationary and mobile phase combinations. Optimized RP-UHPLC separation was carried out using BEH Shield RP18 stationary phase and gradient elution with 25 mmol/L formic acid in acetonitrile and in water. HILIC separation was accomplished with a Cortecs HILIC column and gradient elution with 25 mmol/L ammonium formate pH 3 and acetonitrile. Tandem mass spectrometry (MS/MS) conditions were optimized in both chromatographic modes, but obtained results revealed only a little difference in parameters of capillary voltage and cone voltage. While RP-UHPLC-MS/MS exhibited superior separation selectivity, HILIC-UHPLC-MS/MS has shown substantially higher sensitivity of two orders of magnitude for many compounds. Method validation results indicated that HILIC mode was more suitable for multianalyte methods. Despite better separation selectivity achieved in RP-UHPLC-MS/MS, the matrix effects were noticed while using both chromatographic modes leading to signal enhancement in RP and signal suppression in HILIC.


1989 ◽  
Vol 56 (4) ◽  
pp. 603-611 ◽  
Author(s):  
Marcel A. Juillerat ◽  
Robert Baechler ◽  
Raphael Berrocal ◽  
Serge Chanton ◽  
Jean-Claude Scherz ◽  
...  

SummaryTryptic phosphopeptides were obtained from whole bovine casein by chromatography on the anion exchange resin QAE-Sephadex A 25. Salt gradient elution of the column allowed separation of non-phosphorylated peptides from phosphorylated species. The preparations obtained contained at least seven distinct phosphopeptides of which the following casein fragments were identified: αs1(43–58):2P, αs1(59–79): 5P, αs2(46–70): 4P, β(1–28): 4P, β(2–28): 4P, and β(33–48): 1P. Fast protein liquid chromatography (FPLC) on Mono Q HR 5/5 resin showed that the phosphopeptides were eluted in the same order as from the QAE-Sephadex resin. However, on the analytical column HR 5/5 the fragments αs1(59–79): 5P and β(2–28): 4P, having the same net charge under the conditions of chromatography, co-eluted, whereas they were at least partly separated on the preparative column HR 16/10. Following enzymic dephosphorylation, the peptides eluted at lower salt strength in the gradient. FPLC on Mono Q resin thus permitted dephosphorylation to be monitored and intermediates between the parent species and the fully dephosphorylated peptide to be identified.


1994 ◽  
Vol 683 (2) ◽  
pp. 321-334 ◽  
Author(s):  
Lillian S. Madamba-Tan ◽  
Joost K. Strasters ◽  
Morteza G. Khaledi

Sign in / Sign up

Export Citation Format

Share Document