scholarly journals Qualitative and Quantitative Reversed-Phase Liquid Chromatography of a New Bisisoxazolylnaphthoquinone

2002 ◽  
Vol 85 (2) ◽  
pp. 349-354
Author(s):  
Carola F Ferreyra ◽  
Cristina S Ortiz ◽  
María M de Bertorello
Keyword(s):  
Degradation Products ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Symmetry Factor ◽  
Phase Liquid ◽  
Internal Standardization ◽  
The Stability ◽  
Ph Range ◽  
Liquid Chromatographic ◽  
Decomposition Path

Abstract The main objective of this study was to develop and test the applicability of a sensitive, accurate, and precise liquid chromatographic (LC) method for evaluating the stability characteristics of a new bisisoxazolylnaphthoquinone, 2-(3,5-dimethyl-4-isoxazolylamino)-N-(3,5-dimethyl-4-isoxazolyl)-1,4-naphthoquinone-4-imine compound 1. The method was shown to be selective and stability-indicating. Isocratic elution with a mobile phase of methanol–water (75 + 25, v/v) on a reversed-phase column with UV detection at ambient temperature completely resolved compound 1 from its degradation products. The LC system was calibrated by plotting peak responses versus known concentrations of a reference standard by using an internal standardization procedure. Complete elution occurred after 12 min with a peak symmetry factor of 0.95 for the drug peak. The kinetic degradation of compound 1 was studied over a pH range of 0.88–14.00 to determine the kinetic parameters involved in its decomposition path in aqueous solution.

scholarly journals Liquid Chromatographic/Mass Spectrometric Determination of Desmedipham and Phenmedipham and Their Metabolites in Soil

2001 ◽  
Vol 84 (5) ◽  
pp. 1407-1412 ◽  
Author(s):  
Daniela Perret ◽  
Alessandra Gentili ◽  
Stefano Marchese ◽  
Aldo Marino ◽  
Federica Bruno
Keyword(s):  
Reversed Phase ◽  
Soil Types ◽  
Liquid Chromatography Mass Spectrometry ◽  
Reversed Phase Liquid Chromatography ◽  
Soil Suspension ◽  
Simple Method ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Chromatographic Mass

Abstract A simple method is described for the simultaneous determination of residues of 2 carbamate herbicides (phenmedipham and desmedipham) and related metabolites (m-aminophenol, aniline, and m-toluidine) in soil. The analytes are extracted from spiked soils with methanol. The solvent/soil suspension is centrifuged, and the supernatant is directly injected, without any further cleanup, into a reversed-phase liquid chromatography/mass spectrometry apparatus equipped with a TurboIonSpray interface. The method was tested on 5 soils having different physicochemical properties. Recoveries from the soil types, spiked over the range of 50–200 ppb, were essentially quantitative for each analyte. The detection limits of the method are ≤25 ng/g.

scholarly journals Simultaneous Determination of Hyoscine Butylbromide and Ketoprofen in Pharmaceutical Preparations by Spectrophotometric and Liquid Chromatographic Methods

2007 ◽  
Vol 90 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Yasser Shaker El-Saharty ◽  
Fadia H Metwally ◽  
Mohamed Refaat ◽  
Sonia Zaki El-Khateeb
Keyword(s):  
Pharmaceutical Preparations ◽  
Standard Addition ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Hyoscine Butylbromide ◽  
Mathematical Algorithm ◽  
Accuracy And Precision ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A binary mixture of hyoscine butylbromide and ketoprofen was determined by 4 different methods. The first involved determination of hyoscine butylbromide and ketoprofen using the ratio-spectra first-derivative spectrophotometric technique at 211 and 234 nm over the concentration ranges of 2-14 and 5-45 μg/mL with mean accuracies 99.84 ± 0.92 and 99.98 ± 0.64%, respectively. The second method utilized second-derivative spectrophotometry over the concentration ranges of 2-14 and 5-35 μg/mL with mean accuracies 99.32 ± 1.06 and 99.55 ± 1.15%, respectively. The third method was based on the resolution of the 2 components by bivariate calibration depending on a simple and rapid mathematical algorithm and quantitative evaluation of the absorbances at 206 and 254 nm over concentration ranges of 2-16 and 5-35 μg/mL; mean accuracies of 100.21 ± 1.30 and 100.19 ± 1.07% were obtained for hyoscine butylbromide and ketoprofen, respectively. The fourth method was reversed-phase liquid chromatography using 0.05 M ammonium dihydrogen phosphateacetonitrilemethanol (20 + 30 + 6, v/v) as the mobile phase with ultraviolet detection at 220 nm over concentration ranges of 1-90 and 5-70 μg/mL; mean accuracies were 99.92 ± 1.02 and 99.61 ± 0.98%, respectively. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical preparations. The methods retained their accuracy and precision when the standard addition technique was applied. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.

scholarly journals Liquid Chromatographic Method for Determining Thiodicarb in Technical Products and Formulations: CIPAC Collaborative Study

1998 ◽  
Vol 81 (2) ◽  
pp. 341-343
Author(s):  
Alan R Hanks ◽  
◽  
J Abedi ◽  
E De Aguila ◽  
F Bodzian ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Liquid Chromatographic Method ◽  
Wettable Powder ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Technical Products

abstract A liquid chromatographic method for determining thiodicarb in technical products and formulations was evaluated by 25 participants from 19 laboratories. Data from 19 laboratories were used in statistical analysis to characterize method performance.Two technical materials, a suspension concentrate, a wettable powder, and a water dispersable granule were analyzed. Thiodicarb was determined by reversed-phase liquid chromatography using a mobile phase of methanol and water. Chromatography was performed on a C8 column with detection at 254 nm. Quantitation was achieved by using an internal standard and peak area ratios.

Normal-phase and reversed-phase liquid chromatographic techniques for the determination of dithranol and its degradation products

1989 ◽  
Vol 467 ◽  
pp. 414-422 ◽  
Author(s):  
Irene C.L. Cheah ◽  
Balvant R. Sitaram ◽  
Arthur Pappas ◽  
Nguyen L. Thi ◽  
Barrie C. Finnin ◽  
...  
Keyword(s):  
Degradation Products ◽  
Reversed Phase ◽  
Normal Phase ◽  
Chromatographic Techniques ◽  
Phase Liquid ◽  
Liquid Chromatographic

Stability-indicating LC method for the determination of cephalothin in lyophilized powder for injection

2014 ◽  
Vol 6 (12) ◽  
pp. 4437-4445 ◽  
Author(s):  
Karen de Souza Rugani ◽  
Hérida Regina Nunes Salgado
Keyword(s):  
Liquid Chromatography ◽  
Degradation Products ◽  
Reversed Phase ◽  
Forced Degradation ◽  
Antimicrobial Compound ◽  
Reversed Phase Liquid Chromatography ◽  
Stability Indicating ◽  
Forced Degradation Studies ◽  
Phase Liquid

A stability-indicating gradient reversed phase liquid chromatography (RP-LC) method has been developed for the quantitative determination of cephalothin (CET), an antimicrobial compound, in the presence of its impurities and degradation products generated from forced degradation studies.

scholarly journals Studies on Paliperidone in OROS Tablets: Extraction Procedure and Chromatographic Analysis

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Fábio Barbosa ◽  
Luciano Mantovani ◽  
Cássia V. Garcia ◽  
Andreas S. L. Mendez
Keyword(s):  
Oral Delivery ◽  
Degradation Products ◽  
Extraction Procedure ◽  
Reversed Phase ◽  
Forced Degradation ◽  
Phase System ◽  
Stability Indicating ◽  
Ultrasonic Bath ◽  
The Stability ◽  
Liquid Chromatographic

A stability-indicating liquid chromatographic (LC) method was studied for the determination of paliperidone in osmotic-controlled release oral delivery system (OROS) tablets. A tablet extraction procedure was developed by testing the efficiency of solvents (water, HCl, NaOH, acetonitrile, methanol) and techniques (ultrasonic bath, magnetic stirrer), and evaluating the release of the drug with respect to time. A forced degradation study was conducted to demonstrate the stability-indicating power of the method. Chromatographic separation was achieved using an isocratic elution in a reversed-phase system with a mobile phase prepared from a mixture of phosphate buffer and acetonitrile. The use of an ultrasonic bath demonstrated paliperidone release from OROS tablets in a total time of 60 min. Verifying the efficiency of the chromatographic procedure, the theoretical plates (N=12634.21) and tailing factor (tf=1.31) were constant during repeated injections. The retention time of paliperidone was 4.8 min, and the method was validated within the concentration range of 10–50 μg mL-1 (r=0.9999). Adequate reproducibility (RSD% = 0.30–0.59), interday precision (RSD%=1.81), and accuracy were obtained. The proposed method was successfully applied to paliperidone determination in the presence of degradation products, and an efficient extraction procedure from the OROS tablets was developed.

Simultaneous Assay of Corticosterone and Cortisol in Plasma by Reversed-Phase Liquid Chromatography

1992 ◽  
Vol 38 (3) ◽  
pp. 346-352 ◽  
Author(s):  
M Hariharan ◽  
S Naga ◽  
T VanNoord ◽  
E K Kindt
Keyword(s):  
Extraction Method ◽  
Solid Phase ◽  
Internal Standard ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Ultraviolet Detector ◽  
Liquid Chromatographic Method ◽  
Analytical Recovery ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract We have developed a simple, specific, and sensitive reversed-phase liquid-chromatographic method for accurate and simultaneous analysis of corticosterone and cortisol in human plasma. We achieved a detection limit of 300 ng/L for both steroids by modifying the old solid-phase extraction method to make use of "Tef Elutor" C18 columns, using a minibore (100 x 2 mm) analytical column, and using an ultraviolet detector with a 10-mm-pathlength flow cell. With the new extraction method absolute extraction efficiencies were greater than 90% for all the analytes, including the internal standard, flumethasone. The mobile phase was water (containing 5 mL of triethylamine per liter and citric acid to adjust the pH to 6.5), tetrahydrofuran, and acetonitrile (82/10/8 by vol). The average interassay CV for corticosterone at 0-25 micrograms/L was 6.5%; that for cortisol at 0-300 micrograms/L was 3.8%. The analytical recovery relative to the internal standard was 100.2% for cortisol and 102.6% for corticosterone. Possible interferences from drugs and other steroids were studied.

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