scholarly journals Rapid determination of theaflavins by HPLC with a new monolithic column

2019 ◽  
Vol 37 (No. 2) ◽  
pp. 112-119 ◽  
Author(s):  
Jianyong Zhang ◽  
Hongchun Cui ◽  
Heyuan Jiang ◽  
Lei Fang ◽  
Weiwei Wang ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Mobile Phase ◽  
High Performance ◽  
Rapid Determination ◽  
Monolithic Column ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
New Strategy

The quantitative determination of four theaflavin monomers by a rapid reversed-phase high performance liquid chromatographic method was developed. A new RP-18 end-capped column with particle size 2 µm and equilibrated to 35°C in a Shimadzu temperature controller module was used. Four theaflavin monomers were successfully separated in 8 min by the new strategy, comparing to 20–85 min by HPLC in the peer literature reports. Linear gradient elution: from 92% mobile phase A (v) to 76% mobile phase A (v) during early 3 min and then 92% mobile phase A (v) till 8 min at elution flow rate 1.5 ml/min. The limits of detection and quantification were in the range of 0.1–0.3 and 0.4–1.1 mg/l. Satisfactory recoveries of theaflavin, theaflavin-3-gallate, theaflavin-3’-gallate and theaflavin-3,3’-gallate were 97.5–102.6, 98.6–102.4, 99.6–105.4, and 95.5–105.4%, respectively. The new method was applied to quantitative analysis theaflavins of tea samples, including 10 black teas, 5 oolong teas, and 5 green teas. This method is suitable for the rapid, accurate and inexpensive quantitative analysis of theaflavins under the basic detection conditions of HPLC.

scholarly journals DEVELOPMENT AND VALIDATION OF A HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD DETERMINATION OF ZIDOVUDINE ENCAPSULATED IN PCL NANOPARTICLES

2017 ◽  
Vol 1 (2) ◽  
pp. 1-8
Author(s):  
Milena Cristina Ribeiro Souza Magalhães ◽  
Alisson Samuel Portes Caldeira ◽  
Hanna De Sousa Rocha Almeida ◽  
Sílvia Ligório Fialho ◽  
Armando Da Silva Cunha Junior
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Liquid Chromatographic Method ◽  
Development And Validation ◽  
Liquid Chromatographic ◽  
Isocratic Mode

A reversed-phase high-performance liquid chromatographic (HPLC) method was developed and validated for the determination of encapsulation efficiency of zidovudine in nanoparticules. The method was carried out in isocratic mode using 0.040M sodium acetate: methanol: acetonitrile: glacial acetic acid (880:100:20:2) as mobile phase, a C8 column at 25ºC and UV detection at 240 nm. The method was linear (r2 ˃ 0.99) over the range of 25.0-150.0 μg/mL, precise (RSD ˂ 5%), accurate (recovery = 100.5%), robust and selective. The validated HPLC-UV method can be successfully applied to determine the rate of zidovudine in nanoparticules.

A high-performance liquid-chromatographic method for routine simultaneous determination of nicotine and cotinine in plasma.

1988 ◽  
Vol 34 (4) ◽  
pp. 724-729 ◽  
Author(s):  
M Hariharan ◽  
T VanNoord ◽  
J F Greden
Keyword(s):  
Simultaneous Determination ◽  
Mobile Phase ◽  
High Performance ◽  
Methylene Chloride ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Standard Curve ◽  
Liquid Chromatographic

Abstract We describe a rapid, sensitive method for the routine simultaneous determination of nicotine and cotinine in 1 mL of plasma. Extraction in 10-mL screw-capped Teflon tubes with methylene chloride after deproteinization with trichloroacetic acid eliminated emulsion formation. The extract, after evaporation and reconstitution in 30 microL of mobile phase, is injected into a reversed-phase C-18 ion-pair column of an isocratic high-performance liquid-chromatographic unit. Absorbance is monitored at 256 nm. The mobile phase is a citrate-phosphate (30 mmol each per liter) buffer mixture containing 50 mL of acetonitrile and 1 mmol of sodium heptanesulfonate per liter. 2-Phenylimidazole is the internal standard. The detection limit is 1 microgram/L for nicotine and 3 micrograms/L for cotinine. The standard curve is linear from 0 to 700 micrograms/L for both compounds. The average CV for nicotine in the concentration range 0-100 micrograms/L is 6.5%, and that for cotinine in the concentration range 50-700 micrograms/L is 4%.

scholarly journals Determination of Pantoprazole Sodium and Lansoprazole in Individual Tablet Dosage Forms by RP-HPLC Using Single Mobile Phase

2009 ◽  
Vol 6 (2) ◽  
pp. 489-494 ◽  
Author(s):  
B. Prasanna Kumar Reddy ◽  
Y. Ramanjaneya Reddy ◽  
D. Ramachandran
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Pharmaceutical Products ◽  
Liquid Chromatographic Method ◽  
Phase Liquid ◽  
Tablet Dosage ◽  
Liquid Chromatographic

A simple, sensitive and precise high performance liquid chromatographic method for the analysis of pantoprazole sodium and lansoprazole has been developed, validated and used for the determination of compounds in commercial pharmaceutical products. The compounds were well separated an isocratically on a C18column [Inertsil C18, 5μ, 150 mm x 4.6 mm] utilizing a mobile phase consisting of acetonitrile: phosphate buffer (60:40, v/v, pH 7.0) at a flow rate of 1.0 mL/min with UV detection at 230 nm. The retention time of pantoprazole sodium and lansoprazole was found to be 2.017 min and 2.538. The procedure was validated for linearity (Correlation coefficient=0.999). The study showed that reversed-phase liquid chromatography is sensitive and selective for the determination of pantoprazole sodium and lansoprazole using single mobile phase.

scholarly journals DETERMINATION OF 5H-BENZO[2,3][1,4]OXAZEPINO[5,6-B]INDOLES IN RAT PLASMA BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC-ULTRAVIOLET METHOD: APPLICATION TO PHARMACOKINETIC STUDIES

2017 ◽  
Vol 10 (12) ◽  
pp. 425 ◽  
Author(s):  
Ashok K Singh ◽  
Vinit Raj ◽  
Amit Rai ◽  
Amit K Keshari ◽  
Pranesh Kumar ◽  
...  
Keyword(s):  
High Performance ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Rat Plasma ◽  
Reversed Phase ◽  
Pharmacokinetic Studies ◽  
Relative Standard ◽  
Liquid Chromatographic

Objective: Recently, we reported newly synthesized 5H-benzo[2,3][1,4]oxazepino[5,6-b]indole) derivatives and proved their cytotoxicity against hepatocellular carcinoma specific Hep-G2 cell lines. We attempted herein to describe a reversed-phase high-performance liquid chromatographic method for the determination of three most active compounds 6a, 10a, and 15a in rat plasma to predict their pharmacokinetics parameters before in vivo study.Methods: A rapid and sensitive reversed-phase high-performance liquid chromatographic was employed for the determination of 6a, 10a, and 15a in rat plasma. Each compound was separated by a gradient elution of acetonitrile and water with 1 mL/min flow rate. The detector was set at 270, 285, and 275 nm for 6a, 10a, and 15a and the recorded elution times were 2.00, 2.87, and 1.88 min, respectively.Results: The calibration curve was linear with R2 of 0.938, 0.875, and 0.923 over the concentration range of 0.1–50 μg/mL. The inter- and intra-day variations of the assay were lower than 12.26%; the average recovery of 6a, 10a, and 15a was 97.31, 92.56, and 95.23 % with relative standard deviation of 2.12%, 3.25%, and 2.28%, respectively. The Cmax and Tmax were ~ 46.34, 18.56, and 25.65 μg/mL and 2.0, 4.0, and 4.0 h for 6a, 10a, and 15a, respectively, which indicate a robust method of detection in the present experiment.Conclusion: The study suggests that all of the three compounds have a lower rate of absorption, higher volume of distribution, and lower clearance rate, indicating good therapeutic response for in vivo activity. 

Liquid-chromatographic determination of alpha- and gamma-tocopherols in erythrocytes, with fluorescence detection.

1983 ◽  
Vol 29 (10) ◽  
pp. 1840-1842 ◽  
Author(s):  
J Lehmann ◽  
H L Martin
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We have adapted to erythrocytes a method for the determination of alpha- and gamma-tocopherols in plasma and platelets. Erythrocytes (50 microL) were extracted with methanol containing tocol (internal standard) and pyrogallol. Tocopherols were partitioned into chloroform, washed, and injected in methanol onto a reversed-phase (C18) "high-performance" liquid-chromatographic column. The mobile phase was methanol/water (99/1 by vol) at a flow rate of 2 mL/min and detection was with a "high-performance" spectrophotofluorometer. The limit of detection for either tocopherol is 0.10 microgram/mL of packed cells. Analytical recoveries ranged from 93 to 104%. Some values for tocopherols in human erythrocytes are presented.

Quantitative Determination of Anthraquinones and Resveratrol in Polygonum Cillinerve (Nakai) Ohwi by HPLC-PAD

2017 ◽  
Vol 100 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Yanfang Wu ◽  
Xinsheng Wang ◽  
Pu Liu ◽  
Qingshan Niu ◽  
Qinan Wu
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Geographical Area ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Column Temperature ◽  
Photodiode Array ◽  
Funiu Mountain ◽  
Phase Column

Abstract A simple, sensitive, and validated high-performance liquid chromatography-photodiode array method has been established for the simultaneous determination of anthraquinones and resveratrol in Polygonum Cillinerve (Nakai) Ohwi (Zhushaqi in Chinese). The evaluation was performed using a Sunfire C18 reversed-phase column with 30°C column temperature. The mobile phase was composed of a gradient elution of 0.5% acetic acid (solvent A) and methanol (solvent B) with flow rate of 1.0 mL/min. The detection wavelength was at 254nm. The method developed and validated is simple, shows good linearity, sensitivity, precision, and recovery, and is applied to analyze anthraquinones and resveratrol in 13 batches of Zhushaqi. The results show that the target compounds of Zhushaqi are significantly different among these samples. Based on results of the statistical analysis, the samples collected from Funiu Mountain were clustered together, and the samples obtained fromBozhou Market were close together. The developed method can be a useful tool in quality control and used to evaluate difference and to identify the geographical area of Zhushaqi, and also to provide technical support for the pharmacological and clinical research of related drugs.

scholarly journals Application of Factorial and Doehlert Designs for the Optimization of the Simultaneous Separation and Determination of Antimigraine Drugs in Pharmaceutical Formulations by RP-HPLC-UV

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Sami Jebali ◽  
Chaouki Belgacem ◽  
Mohamed Radhouen Louhaichi ◽  
Senda Bahri ◽  
Latifa Latrous El Atarche
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Sodium Perchlorate ◽  
Pharmaceutical Formulations ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Pharmaceutical Products ◽  
Rp Hplc ◽  
Simultaneous Separation

A sensitive, precise, accurate, and specific isocratic reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the simultaneous separation and determination of zolmitriptan, naratriptan, dihydroergotamine, ketotifen, and pizotifen in pharmaceutical formulations has been developed and validated. An experimental design was applied for the optimization of the chromatographic parameters. A two-level full factorial 2k was used for studying the interaction between the variables to be optimized: the percentage of acetonitrile in the mobile phase, mobile-phase pH, nature of the buffer, and column oven temperature. The most significant parameters are the percentage of acetonitrile and the mobile-phase pH. These significant parameters were optimized using the Doehlert matrix. The optimum separation was achieved by means of a Waters XBridge C18 column (250 mm × 4.6 mm, 5 μm) with a mobile phase consisting of acetonitrile and a 10 mM sodium perchlorate buffer (38 : 62, v/v) at a flow rate of 1.0 mL·min−1 and UV detection at 220 nm. The selectivity, method linearity, accuracy, and precision were examined as part of the method validation. The described method shows excellent linearity over a range of 30 to 70 μg·mL−1 for all compounds with correlation coefficients higher than 0.995. The standard deviations of the intraday and interday precision were between 0.75 and 1.94%. The validated method was successfully applied to perform routine analysis of these compounds in different pharmaceutical products such as syrups and tablets. In the presence of some preservatives, it was found that there were no peaks at the related peak locations.

scholarly journals Qualitative and Quantitative Analysis of the Main Constituents of Radix Ilicis Pubescentis by LC-Coupled with DAD and ESIMS Detection

2010 ◽  
Vol 5 (1) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Wen-Yuan Liu ◽  
Feng Feng ◽  
Cheng-Xia Yu ◽  
Ning Xie
Keyword(s):  
Quantitative Analysis ◽  
High Performance ◽  
Southern China ◽  
Accurate Determination ◽  
Extraction Procedure ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Array Detector ◽  
Phase Detection

A sensitive and selective high performance liquid chromatographic method coupled with DAD detection is presented for quality control of Radix Ilicis Pubescentis. By means of this analytical procedure the major individual constituents (ilexoside O, ilexgenin A, ilexsaponin A1, ilexsaponin B1, liriodendin and acanthoside B) could be quantified simultaneously. LC-ESIMS was applied for identification of the six compounds in the plant by comparing their m/z value and retention times with those of selected standards. For quantitative analysis, the extraction procedure and the extraction solvent were optimized in order to ensure the exhaustive extraction of the plant material. The HPLC conditions were evaluated and optimized for the exact quantification of all six individual compounds. Chromatographic separation was carried out on a C18 column using gradient elution with acetonitrile and 0.1% phosphoric acid as the mobile phase. Detection was carried out using a photodiode array detector. The calibration curves for determination of the six constituents showed good linearity over the investigated ranges (r2>0.999). Measurement of intra-day and inter-day variability (expressed as RSD value) was conducted to assess precisions of the method, and RSD (%) of intra- and inter-day variation were between 1.56-3.36% and 1.61-3.58%, respectively. The recoveries of the six compounds were between 96.4-102.2%, with RSD (%) values ranging from 1.7-3.8%. These validation results demonstrated the suitability of the method for the precise and accurate determination of the main constituents in Radix Ilicis Pubescentis. The method was successfully applied for quality evaluation of 12 batches of Radix Ilicis Pubescentis obtained from different regions of southern China. The contents of the six major constituents varied significantly due to their different origins, which can be used as an aid to assessing the quality of Radix Ilicis Pubescentis.

Liquid-chromatographic determination of aminoglutethimide in plasma.

1983 ◽  
Vol 29 (6) ◽  
pp. 1104-1105 ◽  
Author(s):  
B A Robinson ◽  
F N Cornell
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Ammonium Phosphate ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple, rapid "high-performance" liquid-chromatographic procedure is presented for the determination of aminoglutethimide in plasma. After precipitation of the protein with acetonitrile, an aliquot of the supernate is injected directly onto a radially compressed, reversed-phase column. The aminoglutethimide is isocratically eluted with a mobile phase of acetonitrile/water/tert-butyl ammonium phosphate. The method is both accurate and precise and has been in routine use in our laboratory for more than 12 months.

scholarly journals Determination of Catechin and Epicatechin Content in Chocolates by High-Performance Liquid Chromatography

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Raju V. S. S. Gottumukkala ◽  
Nareshraju Nadimpalli ◽  
Kannababu Sukala ◽  
Gottumukkala V. Subbaraju
Keyword(s):  
High Performance ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
High Concentration ◽  
Uv Visible ◽  
Liquid Chromatographic ◽  
Interday Precision

A simple and sensitive reversed phase high-performance liquid chromatographic (HPLC) method has been developed for the determination of catechin and epicatechin in cocoa powder and chocolates. The separation was achieved on a reversed phase C 18 column (TARGA) 5 μm by gradient elution with a flow rate of 1.0 mL/minute with an operating temperature of 30°C and detection with a UV-Visible detector was at 280 nm. The method was validated for linearity, precision, intra- and interday precision, and accuracy. The developed method is successfully applied for the determination of catechin and epicatechin content in chocolates. The Godiva brand chocolate contains high concentration of epicatechin.

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