scholarly journals Automated isocratic high-performance liquid chromatography of inositol phosphate isomers

1989 ◽  
Vol 262 (3) ◽  
pp. 997-1000 ◽  
Author(s):  
K A Wreggett ◽  
R F Irvine
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Anion Exchange ◽  
High Performance ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Direct Analysis ◽  
Isocratic Elution ◽  
Anion Exchange Resins ◽  
Exchange Resins

Isomers of inositol phosphates from biological samples can be analysed by anion-exchange h.p.l.c., by using isocratic elution with phosphate buffers. The method involves the preliminary processing of the extracted samples with conventional soft-gel anion-exchange resins, including the commonly used Dowex resins, followed by direct analysis with h.p.l.c. of a portion of relevant fractions. Run times (up to 20 min) and collected fraction numbers (up to 24) are minimal, so that if the method is used in conjunction with automated h.p.l.c. injection a high throughput of samples is achieved.

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.

Anion-exchange chromatography of proteins on AG MP-1 using high-performance liquid chromatography equipment

1984 ◽  
Vol 142 (2) ◽  
pp. 373-377 ◽  
Author(s):  
John T. Axelson ◽  
James W. Bodley ◽  
Jeou-Yuan Chen ◽  
Patricia C. Dunlop ◽  
Luann P. Rosenthal ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Anion Exchange ◽  
High Performance ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography
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