scholarly journals The determination of coumestrol in alfalfa (Medicago sativa) by capillary electrophoresis

2011 ◽  
Vol 48 (No. 5) ◽  
pp. 224-229 ◽  
Author(s):  
J. Moravcová ◽  
T. Kleinová ◽  
R. Loučka
Keyword(s):  
Capillary Electrophoresis ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Fused Silica ◽  
Detector Response ◽  
Acid Extraction ◽  
Relative Standard ◽  
Fused Silica Capillary

High performance capillary electrophoresis (HPCE) on an uncoated fused-silica capillary column using a&nbsp;borate buffer at pH 9.2 as electrolyte and diode-array detection was developed for the determination of coumestrol in alfalfa. The linear detector response was established in the concentration range 0.76&ndash;140 mg.dm<sup>&ndash;3</sup>, the minimum detectable limit was 0.39 mg.dm<sup>&ndash;3</sup>, and migration time of coumestrol was 5 min. 3-Isobutyl-1-methylxanthin was used as an internal standard. Coumestrol was isolated by acid extraction employing a&nbsp;mixture hydrochloric acid-acetonitrile at 95&deg;C for 30 min followed by solid phase extraction. Relative standard deviations of reproducibility and repeatability were 1.77% and 5.49%, respectively. Spiking recovery value of 92% was achieved. Alfalfa, variety Morava, contains 148&ndash;248 mg.kg<sup>&ndash;1</sup>&nbsp;coumestrol in dry matter. The proposed method is useful for routine analyses.

scholarly journals The determination of isoflavones and coumestrol by capillary electrophoresis

2013 ◽  
Vol 19 (No. 4) ◽  
pp. 132-138 ◽  
Author(s):  
J. Moravcová ◽  
T. Kleinová
Keyword(s):  
Capillary Electrophoresis ◽  
Fused Silica ◽  
Biochanin A ◽  
Detector Response ◽  
Two Dimensional ◽  
Nmr Spectrum ◽  
Fused Silica Capillary ◽  
First Time ◽  
Silica Capillary

The separation of six isoflavones (biochanin A, isoformononetin, formononetin, prunetin, daidzein and genistein) and coumestrol on an uncoated fused-silica capillary electrophoresis column was optimised using alkaline borate buffer as electrolyte and DAD detection. A baseline separation of all analytes except a pair, formononetin-biochanin A was achieved at pH 10.5 in 25 min. Detection limits were low (0.1 &micro;g/ml) and the linearity of the detector response was established in the concentration range 0.4&ndash;60&nbsp;&micro;g/ml (180 &micro;g/ml for coumestrol). Coumestrol was synthesized and the carbon signals in 13C-NMR spectrum of both coumestrol and di-O-acetylcoumestrol were assigned for the first time using two-dimensional HMQC technique.

Determination of Musk Ambrette in Fragrance Products by Capillary Gas Chromatography with Electron Capture Detection: Interlaboratory Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1467-1471 ◽  
Author(s):  
Harris H Wisneski ◽  
Ronald L Yates ◽  
Donald C Havery
Keyword(s):  
Electron Capture ◽  
Internal Standard ◽  
Fused Silica ◽  
Electron Capture Detection ◽  
Similar Response ◽  
Relative Standard ◽  
Fused Silica Capillary ◽  
Gas Chromatographic Method ◽  
Musk Ambrette

Abstract A gas chromatographic method that uses an internal standard additions technique is described for the determination of musk ambrette (MA) in fragrance products. A solution containing the product and a known amount of an internal standard, musk tibetene (MT), is injected directly into a gas chromatograph equipped with an electron capture detector. The chromatographic separation of the components on a wide-bore fused silica capillary column is recorded and a response constant is calculated from MA and MT peak heights. A similar response constant is also calculated for a standard solution containing known concentrations of MA and MT. The MA content of the fragrance product is then calculated. Average recoveries of MA from fragrance products ranged from 97.6 to 102.3%. The method was also evaluated collaboratively by 6 laboratories. In this study, the reproducibility relative standard deviation for MA in 6 fragrance test samples ranged from 2.78 to 22.87%.

Determination of Ferulic Acid in“SHI-QUAN-DA-BU” Pills by High Performance Capillary Electrophoresis

2013 ◽  
Vol 850-851 ◽  
pp. 1152-1155
Author(s):  
Hai Xing Liu ◽  
Qing Liu ◽  
Xiao Yang Xu ◽  
Guo Dong Feng ◽  
Lin Tong Wang ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Ferulic Acid ◽  
High Performance ◽  
Fused Silica ◽  
Borax Solution ◽  
Fused Silica Capillary ◽  
High Performance Capillary Electrophoresis ◽  
Silica Capillary Column ◽  
Silica Capillary

High performance capillary electrophoresis (HPCE) was used in this text to determine the content of ferulic acid in “SHI-QUAN-DA-BU” Pills. Electrophoretic separation conditions: Uncoated fused silica capillary column(75um×49/58cm), injection height 7.5cm, 30mmol•L-1borax solution, separation voltage 20kV, injection time 15s, detection wavelength 315 nm, experimental temperature 20°C. Linearity was kept in the concentration ranging from 1~31.25 mg·L-1of ferulic acid with correlation coefficient of 0.970. The average recovery was 97.56% and RSD value was 6.4%. The content of ferulic acid was 0.0855 mg/g (n=6).

ICH/FDA Guidelines-Compliant Validated Stability-Indicating HPLC-UV Method for the Determination of Axitinib in Bulk and Dosage Forms

2020 ◽  
Vol 16 (8) ◽  
pp. 1106-1112
Author(s):  
Ibrahim A. Darwish ◽  
Nasr Y. Khalil ◽  
Mohammad AlZeer
Keyword(s):  
High Performance ◽  
Kinase Inhibitor ◽  
Degradation Products ◽  
Internal Standard ◽  
Dosage Forms ◽  
Uv Detector ◽  
Stability Indicating ◽  
Therapeutic Benefits ◽  
Relative Standard

Background: Axitinib (AXT) is a member of the new generation of the kinase inhibitor indicated for the treatment of advanced renal cell carcinoma. Its therapeutic benefits depend on assuring the good-quality of its dosage forms in terms of content and stability of the pharmaceutically active ingredient. Objective: This study was devoted to the development of a simple, sensitive and accurate stabilityindicating high-performance liquid chromatographic method with ultraviolet detection (HPLC-UV) for the determination of AXT in its bulk and dosage forms. Methods: Waters HPLC system was used. The chromatographic separation of AXT, internal standard (olaparib), and degradation products were performed on the Nucleosil CN column (250 × 4.6 mm, 5 μm). The mobile phase consisted of water:acetonitrile:methanol (40:40:20, v/v/v) with a flow rate of 1 ml/min, and the UV detector was set at 225 nm. AXT was subjected to different accelerated stress conditions and the degradation products, when any, were completely resolved from the intact AXT. Results: The method was linear (r = 0.9998) in the concentration range of 5-50 μg/ml. The limits of detection and quantitation were 0.85 and 2.57 μg/ml, respectively. The accuracy of the method, measured as recovery, was in the range of 98.0-103.6% with relative standard deviations in the range of 0.06-3.43%. The results of stability testing revealed that AXT was mostly stable in neutral and oxidative conditions; however, it was unstable in alkaline and acidic conditions. The kinetics of degradation were studied, and the kinetic rate constants were determined. The proposed method was successfully applied for the determination of AXT in bulk drug and dosage forms. Conclusions: A stability-indicating HPLC-UV method was developed and validated for assessing AXT stability in its bulk and dosage forms. The method met the regulatory requirements of the International Conference on Harmonization (ICH) and the Food and Drug Administration (FDA). The results demonstrated that the method would have great value when applied in quality control and stability studies for AXT.

scholarly journals Quantitative Determination of Azithromycin in Human Plasma by Liquid Chromatography–Mass Spectrometry and its Application in Pharmackokinetic Study

2012 ◽  
Vol 11 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Maizbha Uddin Ahmed ◽  
Mohammad Safiqul Islam ◽  
Tasmin Ara Sultana ◽  
AGM Mostofa ◽  
Muhammad Shahdaat Bin Sayeed ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Solid Phase ◽  
Internal Standard ◽  
Extraction Process ◽  
Serum Samples ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Linear Concentration Range ◽  
Linear Concentration

Azithromycin is an effective and well-known antimicrobial agent. In the present study, a simple, sensitive and specific LC/MS/MS method has been developed and validated for the quantification of Azithromycin in  human serum samples using Clarithromycin as internal standard. Azithromycin was extracted from biological matrix  by using solid phase extraction process. The chromatographic separation was performed on Luna C18 (3 ?, 2x150   mm) column with a mobile phase consisting of 35 mM ammonium acetate buffer (mobile phase-A) and acetonitrile  and methanol in ratio of 90:10 ( as mobile phase-B) at a flow rate of 0.25 mL/min. The method was validated over a  linear concentration range of 0.5?50.0 ng/mL and limit of quantification (LOQ) was 0.5 ng/mL with a coefficient of  correlation (r2) = 0.9998. The intra-day and inter-day precision expressed as relative standard deviation were 1.64% – 8.43% and 2.32% – 9.92%, respectively. The average recovery of azithromycin from serum was 98.11%. The method  was successfully applied to a pharmacokinetic study after oral administration of Azithromycin 200 mg/5 ml suspension in healthy Bangladeshi volunteers. DOI: http://dx.doi.org/10.3329/dujps.v11i1.12488 Dhaka Univ. J. Pharm. Sci. 11(1): 55-63, 2012 (June)

High-Performance Liquid Chromatographic Determination of Memantine in Human Urine Following Solid-Phase Extraction and Precolumn Derivatization

2013 ◽  
Vol 96 (6) ◽  
pp. 1302-1307 ◽  
Author(s):  
Karim Michail ◽  
Hoda Daabees ◽  
Youssef Beltagy ◽  
Magdy Abd Elkhalek ◽  
Mona Khamis
Keyword(s):  
Human Urine ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Therapeutic Drug ◽  
Time Interval ◽  
Precolumn Derivatization ◽  
Uv Detector

Abstract A validated HPLC-UV method is presented for the quantification of urinary memantine hydrochloride, a novel medication approved to treat moderate and advanced cases of Alzheimer's disease. The drug and amantadine hydrochloride, the internal standard, were extracted from human urine using SPE. The extract was then buffered and derivatized at room temperature using o-phthalaldehyde in the presence of N-acetyl-L-cyteine. Chromatographic separation of the formed derivatives was achieved on a C18 column using methanol–water mobile phase adjusted to pH 7 and pumped isocratically at 1 mL/min. The UV detector was set at 340 nm. The chromatographic run time did not exceed 10 min. The LOD and LOQ were 8 and 20 ng/mL, respectively. The RSDs for intraday and interday precisions did not exceed 5.5%. The method was used to monitor memantine hydrochloride in human urine in order to determine an appropriate sampling interval for future noninvasive therapeutic drug monitoring. The assay could also be applied to the determination of amantadine. The described assay showed that a postdosing time interval of 25–75 h seems adequate for sampling and monitoring memantine in urine.

scholarly journals High-performance liquid chromatographic determination of famotidine in human plasma using solid-phase column extraction

2003 ◽  
Vol 68 (11) ◽  
pp. 883-892 ◽  
Author(s):  
Dragica Zendelovska ◽  
Trajce Stafilov
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Water Ph ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

A rapid, specific and sensitive high-performance liquid chromatographic method for the determination of famotidine in human plasma has been developed. Famotidine and the internal standard were chromatographically separated from plasma components using a Lichrocart Lichrospher 60 RP select B cartridge for solid-phase separation with a mobile phase composed of 0.1 % (v/v) triethylamine in water (pH 3) and acetonitrile (92:8, v/v). UV detection was set at 270 nm. The calibration curve was linear in the concentration range of 10.0 ? 350.0 ng mL-1. The method was implemented to monitor the famotidine levels in patient samples.

scholarly journals Determination of Chlorinated Phenols in Water and Soil by Capillary Zone Electrophoresis

1997 ◽  
Vol 80 (6) ◽  
pp. 1308-1314 ◽  
Author(s):  
Wayne E Rae ◽  
Charles A Lucy
Keyword(s):  
Capillary Zone Electrophoresis ◽  
Fused Silica ◽  
Soil Samples ◽  
Chlorinated Phenols ◽  
Relative Standard ◽  
Zone Electrophoresis ◽  
Water And Soil Samples ◽  
Fused Silica Capillary ◽  
Capillary Zone

Abstract A capillary zone electrophoresis (CZE) method was developed to separate and determine chlorinated phenols in water and soil samples. A mixture of 16 chlorinated phenols was resolved in 25 min by using a 77 cm (70 cm to detector) × 75 μm fused silica capillary with 0.015M tetraborate/0.045M phosphate (pH 7.3) buffer at 22 kV. Calibration linearities for water samples in the low parts-permillion range were good (correlation coefficient &gt; 0.99) for all solutes except p-chlorophenol. Average precision was 17% relative standard deviation. Typical detection limits were in the 200 μg/L range. Recoveries of chlorinated phenols from synthetic soil samples with methanol were quantitative.

scholarly journals Determination of Tianeptine in Tablets by High-Performance Liquid Chromatography with Fluorescence Detection

2007 ◽  
Vol 90 (3) ◽  
pp. 720-724
Author(s):  
Sevgi Tatar Ulu
Keyword(s):  
Lower Limit ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Linear Calibration ◽  
Fluorescence Detector ◽  
Relative Standard ◽  
Validation Parameters ◽  
Limit Of Quantitation

Abstract A sensitive and selective high-performance liquid chromatographic method has been developed for the determination of tianeptine (Tia) in tablets. The method is based on derivatization of Tia with 4-chloro-7-nitrobenzofurazan (NBD-Cl). A mobile phase consisting of acetonitrile10 mM orthophosphoric acid (pH 2.5; 77 + 23) was used at a flow rate of 1 mL/min on a C18 column. The Tia-NBD derivative was monitored using a fluorescence detector, with emission set at 520 nm and excitation at 458 nm. Gabapentin was selected as an internal standard. Linear calibration graphs were obtained in the concentration range of 45300 ng/mL. The lower limit of detection (LOD) was 10 ng/mL at a signal-to-noise ratio of 4. The lower limit of quantitation (LOQ) was 45 ng/mL. The relative standard values for intra- and interday precision were &lt;0.46 and &lt;0.57%, respectively. The recovery of the drug samples ranged between 98.89 and 99.85%. No chromatographic interference from the tablet excipients was found. The proposed method was validated in terms of precision, robustness, recovery, LOD, and LOQ. All the validation parameters were within the acceptance range. The proposed method was applied for the determination of Tia in commercially available tablets. The results were compared with those obtained by an ultraviolet spectrophotometric method using t- and F-tests.

scholarly journals Determination of Patulin in Apple Juice: Comparative Evaluation of Four Analytical Methods

2007 ◽  
Vol 90 (1) ◽  
pp. 162-166 ◽  
Author(s):  
David R Katerere ◽  
Sonja Stockenström ◽  
Gabriele Balducci ◽  
Gordon S Shephard
Keyword(s):  
Comparative Evaluation ◽  
High Performance ◽  
Apple Juice ◽  
Solid Phase ◽  
Phase Extraction ◽  
Low Concentrations ◽  
Relative Standard ◽  
Purification Methods ◽  
Union Directive

Abstract The performance of 4 purification methods for the analysis of patulin in apple juice was evaluated by high-performance liquid chromatography (HPLC). Samples were spiked with patulin at 10, 20, 50, 100, and 150 ppb (ng/mL) and extracted by one of 4 methods (3 solid-phase extraction and one liquidliquid extraction), and then analyzed by HPLCUV under the same isocratic conditions. The methods were validated for recovery, linearity, and precision at high and low concentrations. Recoveries were all &gt;70% for spiking range 10-150 ppb. The relative standard deviation for repeatability was found to meet European Union Directive requirements. In addition, all the methods showed baseline separation from hydroxymethylfurfural.

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