THE INFLUENCE OF MOBILE-PHASE FLOW-RATE IN RP-LC ON THERMODYNAMIC PARAMETERS STUDIED FOR POLAR COMPOUNDS

2011 ◽  
Vol 34 (7) ◽  
pp. 521-536 ◽  
Author(s):  
Toma Galaon ◽  
Constantin Mihailciuc ◽  
Andrei Medvedovici ◽  
Victor David
Keyword(s):  
Thermodynamic Parameters ◽  
Flow Rate ◽  
Mobile Phase ◽  
Polar Compounds ◽  
Phase Flow ◽  
Mobile Phase Flow Rate

scholarly journals Purification of Flavonoids from Mulberry Leaves via High-Speed Counter-Current Chromatography

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 91 ◽  
Author(s):  
Pian Zhang ◽  
Kang-Ling Zhu ◽  
Jun Zhang ◽  
Yan Li ◽  
Heng Zhang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Mobile Phase ◽  
High Speed ◽  
Separation Efficiency ◽  
Phase Flow ◽  
Mobile Phase Flow Rate ◽  
Mulberry Leaves ◽  
Mulberry Leaf ◽  
Solvent Systems ◽  
Counter Current

In order to obtain high-purity flavonoid products, the extracts from mulberry leaves were separated and purified via high-speed counter-current chromatography (HSCCC). Moreover, the product was detected via high-performance liquid chromatography (HPLC). The characteristic absorption wavelength of the rutin standard for HSCCC detection and HPLC analysis at 257 nm was tested by ultraviolet scanning analysis. The effect of solvent systems and mobile phase flow rate on the separation efficiency were then researched. Finally, the solvent system of V(ethyl acetate):V(n-butanol):V(water) = 4:1:5 was selected as the operating system for HSCCC. This work theoretically analyzed the impact of the molecular structure and polarity of flavonoids on the choice of solvent systems. The results showed that the mobile phase flow rate had a great influence on the separation efficiency. Furthermore, the separation efficiency increased as the mobile phase flow rate decreased. When the mobile phase flow rate was 5 mL/min, the peak time for flavonoids was 140 min, the retention of the stationary phase was 56.4%, and the purity of the product reached 93.8%. The results of this study greatly improved the purity of flavonoids in mulberry leaf and provided a strong support for the separation and purification of mulberry leaf extract.

scholarly journals Flow-dependent separation selectivity for organic molecules on metal–organic frameworks containing adsorbents

2016 ◽  
Vol 52 (30) ◽  
pp. 5301-5304 ◽  
Author(s):  
Anton Peristyy ◽  
Pavel N. Nesterenko ◽  
Anita Das ◽  
Deanna M. D'Alessandro ◽  
Emily F. Hilder ◽  
...  
Keyword(s):  
Flow Rate ◽  
Mobile Phase ◽  
Organic Molecules ◽  
Metal Organic Frameworks ◽  
Phase Flow ◽  
Mobile Phase Flow Rate ◽  
Separation Selectivity ◽  
Metal Organic

A new effect was discovered which allows changes of selectivity by variation of the mobile phase flow rate.

Gas chromatography with programming the mobile phase flow rate

1979 ◽  
Vol 12 (5) ◽  
pp. 271-276 ◽  
Author(s):  
S. A. Volkov ◽  
Yu. A. Sultanovich ◽  
K. I. Sakodinskii
Keyword(s):  
Gas Chromatography ◽  
Flow Rate ◽  
Mobile Phase ◽  
Phase Flow ◽  
Mobile Phase Flow Rate

scholarly journals DETERMINATION OF ARGININE AND ASCORBIC ACID IN EFFERVESCENT TABLETS BY MULTIDIMENSIONAL CHROMATOGRAPHY

2017 ◽  
Vol 1 (2) ◽  
pp. 44-52
Author(s):  
Andrea E. Rech ◽  
Cristina P. Farina ◽  
Pamela C. Lukasewicz Ferreira ◽  
Diogo Miron
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Flow Rate ◽  
Phosphate Buffer ◽  
Mobile Phase ◽  
Direct Method ◽  
Phase Flow ◽  
Mobile Phase Flow Rate ◽  
Multidimensional Chromatography

This paper describes a fast and direct method for quantification of arginine and ascorbic acid (vitamin C) in effervescent tablets. HPLC-UV multidimensional chromatography (RP18 and cyanopropyl columns) was developed and validated. Phosphate buffer 10 mMpH 3.4 was used as mobile phase. Satisfactory resolution between the drugs was obtained with analysis time less than 8.0 min. Method was linear in the ranges of 140-320 mg.mL-1 and 240-560 mg.mL-1 for arginine and ascorbic acid, respectively. Precision showed RSD <2.0%. Recovery was 99.5% and 100.0% for arginine and ascorbic acid, respectively. Robustness was confirmed through factorial analysis 22 (pH and mobile phase flow rate as factors).

Determination of Serum Diclofenac by High-performance Liquid Chromatography by Electromechanical Detection

1985 ◽  
Vol 4 (3) ◽  
pp. 317-322 ◽  
Author(s):  
F. Plavsic ◽  
J. Čulig
Keyword(s):  
Entire Range ◽  
Mobile Phase ◽  
High Performance ◽  
Dose Interval ◽  
Phase Flow ◽  
Electrochemical Detector ◽  
Mobile Phase Flow Rate ◽  
Coefficients Of Variation ◽  
Double Extraction

Diclofenac was isolated from plasma by double extraction with organic solvent. Chromatography was performed on Lichrosorb NH2 column with acetonitrile and perchloric acid (0.0025 mol/l; 35:65, v/v) as the mobile phase (flow rate 0.9 ml/min). The electrochemical detector was operated at +900 mV and sensitivity of 5-10 nA. The sensitivity of the method was 10 μg/1 and the coefficients of variation below 10% in the entire range of the concentration in a dose interval.

scholarly journals Development and Validation of LC Method for the Determination of Famciclovir in Pharmaceutical Formulation Using an Experimental Design

2008 ◽  
Vol 5 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Srinivas Vishnumulaka ◽  
Narasimha Rao Medicherla ◽  
Allam Appa Rao ◽  
G. Edela Srinubabu
Keyword(s):  
Experimental Design ◽  
Flow Rate ◽  
Mobile Phase ◽  
Internal Standard ◽  
Pharmaceutical Formulations ◽  
Hplc Method ◽  
Internal Standard Method ◽  
Intermediate Precision ◽  
Mobile Phase Flow Rate ◽  
Development And Validation

A rapid and sensitive RP-HPLC method with UV detection (242 nm) for routine analysis of famciclovir in pharmaceutical formulations was developed. Chromatography was performed with mobile phase containing a mixture of methanol and phosphate buffer (50:50,v/v) with flow rate 1.0 mL min−1. Quantitation was accomplished with internal standard method. The procedure was validated for linearity (correlation coefficient =0.9999), accuracy, robustness and intermediate precision. Experimental design was used for validation of robustness and intermediate precision. To test robustness, three factors were considered; percentage v/v of methanol in mobile phase, flow rate and pH; flow rate, the percentage of organic modifier and pH have considerable important effect on the response. For intermediate precision measure the variables considered were: analyst, equipment and number of days. The RSD value (0.86%,n=24) indicated an acceptable precision of the analytical method. The proposed method was simple, sensitive, precise, accurate and quick and useful for routine quality control.

scholarly journals RP-HPLC Method Development and Validation for the Estimation of Lansoprazole in Presence of Related Substances by QbD Approach

2021 ◽  
pp. 138-150
Author(s):  
Sachin B. Gholve ◽  
Jaiprakash N. Sangshetti ◽  
Omprakash G. Bhusnure ◽  
Ram S. Sakhare ◽  
Pratap H. Bhosale ◽  
...  
Keyword(s):  
Flow Rate ◽  
Mobile Phase ◽  
Method Development ◽  
Hplc Method ◽  
Drug Substance ◽  
Gastric Ulcers ◽  
Mobile Phase Flow Rate ◽  
Column Temperature ◽  
Rp Hplc

A rapid specific RP-HPLC method has been developed for the determination of Lansoprazole impurities in the drug substance. The control of pharmaceutical impurities is currently a critical issue in the pharmaceutical industry. The International Council for Harmonization (ICH) has formulated a workable guideline regarding the control of impurities. The objective of the recent study was to develop and validate a HPLC method for the quantitative determination of process-related impurities of Lansoprazole in pharmaceutical drug substance. Lansoprazole, 2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl] methyl]-sulfinyl]- 1H-benzimidazole is an proton pump inhibitor used in the management of gastric ulcers. Chromatographic identification of the impurities was carried out by response surface methodology, applying a three-level Box Behnken design with three center points. Three factors selected were a mobile phase, flow rate, column temperature. Evaluation of the main factor, their interaction, and the quadric effect on peak resolution were done on Waters Symmetry C8, 250 x 4.6mm, 5µm column is used for the development of the method. The mobile phase consists of buffer and acetonitrile. The flow rate of the mobile phase was 1.0 ml/min with gradient elution. The column temperature is ambient and the detection wavelength is 235 nm. The injection volume was 10 µL. The method was validated as per ICH guidelines for linearity in the range of 50-150 µg/ml and the LOD & LOQ values obtained were 0.437×10-4 and 0.1325×10-3 µg/ml respectively which specifies the method's sensitivity. The proposed method was successfully used to determine the Lansoprazole impurities in drug substances.

scholarly journals PENETAPAN KADAR DIOSGENIN DALAM EKSTRAK AIR Costus speciosus SECARA HPLC

2017 ◽  
Vol 22 (1) ◽  
pp. 1
Author(s):  
Hari Susanti ◽  
Subagus Wahyuono ◽  
Ratna Asmah Susidarti ◽  
Ika Puspita Sari
Keyword(s):  
Biological Activity ◽  
Mobile Phase ◽  
Chemical Constituents ◽  
Water Extract ◽  
Hplc Method ◽  
Phase Flow ◽  
Column Length ◽  
Mobile Phase Flow Rate ◽  
Costus Speciosus ◽  
Freeze Dryer

Costus speciosus has been reported to have biological activity among antidiabetic, antihyperlipidemia, antioxidants. One of the chemical constituents that is responsible for some of the biological activity is diosgenin. This study aimed to determine diosgenin content of Costus speciosus water extract (CS). Water extract of CS was obtained with infundation method. The extract was dried using freeze dryer. The assay of diosgenin was performed by HPLC method. HPLC system used: LiChrospher® 100 RP-18 endcapped (5 µm) column length 25cm, colimn id 4 mm as stationary phase, acetonitrile-water (9: 1 v/v) as mobile phase, flow rate 2mL/min and UV detection at 205 nm. HPLC method developed was linear in the range 20-200 μg mL with R = 0.9999 ; slope = 6423.7; and intercept = -4280.5; LOD = 2.14 ug/mL and LOQ = 6.50 mg/mL; and recovery 100.63 %. Diosgenin levels in CS was 0.279 %. The developed HPLC method is relatively simple, rapid, sensitive, and accurate to determine the content of diosgenin in water extracts of Costus speciosus.

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