Optimization of experimental conditions for spectrofluorimetric determination of europium, samarium, and terbium as their hexafluoroacetylacetone-trioctylphosphine oxide complexes

1971 ◽  
Vol 43 (3) ◽  
pp. 454-455 ◽  
Author(s):  
Robert Perry. Fisher ◽  
James D. Winefordner
Keyword(s):  
Trioctylphosphine Oxide ◽  
Experimental Conditions ◽  
Spectrofluorimetric Determination ◽  
Optimization Of Experimental Conditions

scholarly journals Spectrofluorimetric determination of amlodipine in human plasma without derivatization

2012 ◽  
Vol 48 (4) ◽  
pp. 719-725 ◽  
Author(s):  
Yucel Kadioglu ◽  
Murat Ozturk
Keyword(s):  
Channel Blocker ◽  
Limit Of Detection ◽  
Plasma Samples ◽  
Experimental Conditions ◽  
Spectrofluorimetric Method ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Spectrofluorimetric Determination ◽  
Better Than

A rapid and sensitive spectrofluorimetric method was developed for the determination of amlodipine (AD), a calcium channel blocker, in the plasma. The type of solvent, the wavelength range, and the range of AD concentration were selected to optimize the experimental conditions. The calibration curves were linear (r² >0.997) in the concentration range of 0.1-12.5 ppm of AD. The limit of quantitation and limit of detection values for the method for plasma samples were 0.1 ppm and 0.07 ppm, respectively. The precision calculated as the relative standard deviation was less than 3.5%, and the accuracy (relative error) was better than 5.5% (n=6). The method developed in this study can be directly and easily applied for the determination of AD in the plasma without derivatization in plasma.

Fluorescence Enhancement of Carbendazim in the Presence of Cyclodextrins and Micellar Media: A Reappraisal

2005 ◽  
Vol 59 (7) ◽  
pp. 873-880 ◽  
Author(s):  
Rubén M. Maggio ◽  
Gisela N. Piccirilli ◽  
Graciela M. Escandar
Keyword(s):  
Sodium Dodecyl ◽  
Fluorescence Emission ◽  
Hexadecyltrimethylammonium Bromide ◽  
Micellar Media ◽  
Experimental Conditions ◽  
Decyltrimethylammonium Bromide ◽  
Spectrofluorimetric Determination ◽  
Organized Media ◽  
Organized Assemblies

This study focuses on the spectrofluorimetric behavior of the pesticide carbendazim in the presence of selected organized assemblies and also on their potential analytical applications. The relatively weak fluorescence emission band of carbendazim is significantly enhanced by micellar media formed by sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, and decyltrimethylammonium bromide. The influence of the surfactant structures, concentrations, and working experimental conditions on the fluorescence spectra of carbendazim was thoroughly evaluated and discussed. Although the interaction of carbendazim with different cyclodextrins is rather weak, it was corroborated that the fluorescence intensity of this compound in the presence of (2-hydroxy)propyl β-cyclodextrin is increased by a factor of two. Among the studied organized media, the cationic surfactant hexadecyltrimethylammonium bromide produced the largest signals for the compound of interest. Consequently, the optimal working conditions for the spectrofluorimetric determination of carbendazim in the presence of the latter detergent were analyzed, concluding that previous literature reports should be reconsidered.

scholarly journals Highly Sensitive Spectrofluorimetric Determination of Ephedrine Hydrochloride in Pharmaceutical Preparations

2006 ◽  
Vol 89 (5) ◽  
pp. 1263-1267 ◽  
Author(s):  
Sevgi Tatar Ulu
Keyword(s):  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Official Method ◽  
Good Precision ◽  
Experimental Conditions ◽  
Ephedrine Hydrochloride ◽  
Highly Sensitive ◽  
Relative Standard ◽  
Spectrofluorimetric Determination

Abstract A sensitive and specific spectrofluorimetry method was developed and validated for the quantification of ephedrine (EP) in pharmaceutical preparations. The method is based on the fluorescent enhancing reaction of EP with 7-chloro-4-nitrobenzofurazan (NBD-CI; derivatization reagent), in borate buffer of pH 9 to yield a yellow, fluorescent product. Under these experimental conditions, the derivatized product of EP had excitation and emission wavelength maxima at 458 and 516 nm, respectively. The linear range of this method was 202500 ng/mL. The detection limit was 7.3 ng/mL EP. Intra- and interday precisions of the assay at 3 concentrations within this range were 0.0371.77%. The low relative standard deviation values indicate good precision, and high recovery values indicate excellent accuracy of the method. The proposed method was applied to the determination of the examined drugs in pharmaceutical formulations, and the results indicate that the method is equally as accurate, precise, and reproducible as the official method.

Antithrombin-mediated Inhibition of Factor Vlla-Tissue Factor Complex by the Synthetic Pentasaccharide Representing the Heparin Binding Site to Antithrombin

1996 ◽  
Vol 76 (01) ◽  
pp. 005-008 ◽  
Author(s):  
Jean Claude Lormeau ◽  
Jean Pascal Herault ◽  
Jean Marc Herbert
Keyword(s):  
Binding Site ◽  
Tissue Factor ◽  
Residual Activity ◽  
Coagulation Factors ◽  
Heparin Binding ◽  
Experimental Conditions ◽  
First Order ◽  
Heparin Binding Site ◽  
Coagulant Activity

SummaryWe examined the effect of the synthetic pentasaccharide representing the minimal binding site of heparin to antithrombin on the antithrombin-mediated inactivation of factor Vila bound to tissue factor. This effect was compared to the effect of unfractionated heparin. Using purified recombinant human coagulation factors and either a clotting or an amidolytic assay for the determination of the residual activity of factor Vila, we showed that the pentasaccharide was an efficient antithrombin-dependent inhibitor of the coagulant activity of tissue factor-factor Vila complex. In our experimental conditions, assuming a mean MW of 14,000 for heparin, the molar pseudo-first order rate constants for ATIII-mediated FVIIa inhibition by ATIII-binding heparin and by the synthetic pentasaccharide were found to be similar with respective values of 104,000 ± 10,500 min-1 and 112,000 ± 12,000 min-1 (mean ± s.e.m., n = 3)

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