scholarly journals Simultaneous Kinetic Spectrophotometric Determination Of Ascorbic Acid And Cysteine With An Optical Probe By Mean Centering Of Ratio Kinetic Profiles Method

2019 ◽  
Vol 14 (3) ◽  
pp. 163-170
Author(s):  
A.B. Vishnikin ◽  
Yu.V. Miekh ◽  
Ya.R. Bazel ◽  
M.E.A. Al-Shwaiyat ◽  
G.O. Petrushina
Keyword(s):  
Ascorbic Acid ◽  
Binary Mixture ◽  
Standard Addition ◽  
Optical Probe ◽  
Addition Method ◽  
Kinetic Measurements ◽  
Mean Centering ◽  
The Difference ◽  
Kinetic Spectrophotometric

A procedure for simultaneous kinetic analysis of a binary mixture of ascorbic acid (Asc) and cysteine (Cys) was developed using the method of mean centering of ratio kinetic profiles. The method is based on the difference in the rate of reactions of Asc and Cys with the complex of iron(III) with o-phenanthroline at pH 7.05. The use of an optical probe simplifies the carrying out of kinetic measurements, allows to obtain highly reproducible (Sr=0.01-0.02) results, and significantly reduces the time of analysis. The method of mean centering of ratio kinetic profiles is superior to the H-Point standard addition method, since it does not require such a long measurement time and there is no restriction on the constancy of absorbance of one of the components. Asc and Cys can be determined in the concentration range from 1 to 10 mg/L. The method was successfully used to determine Asc and Cys in dietary supplements.

Simultaneous Kinetic Spectrophotometric Determination of Ascorbic Acid and L-Cysteine by H-Point Standard Addition Method

2004 ◽  
Vol 148 (3-4) ◽  
pp. 259-265 ◽  
Author(s):  
Jahanbakhsh Ghasemi ◽  
Soodabe Seifi ◽  
Mozafar Sharifi ◽  
Rostam Ghorbani ◽  
Ali Amini
Keyword(s):  
Ascorbic Acid ◽  
Spectrophotometric Determination ◽  
Standard Addition ◽  
Standard Addition Method ◽  
Addition Method ◽  
Kinetic Spectrophotometric

scholarly journals Comparative Study of Novel Ratio Spectra and Isoabsorptive Point Based Spectrophotometric Methods: Application on a Binary Mixture of Ascorbic Acid and Rutin

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Hany W. Darwish ◽  
Ahmed H. Bakheit ◽  
Ibrahim A. Naguib
Keyword(s):  
Ascorbic Acid ◽  
Binary Mixture ◽  
High Performance ◽  
Pharmaceutical Tablets ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
Ratio Difference ◽  
Mean Centering ◽  
Assay Conditions

This paper presents novel methods for spectrophotometric determination of ascorbic acid (AA) in presence of rutin (RU) (coformulated drug) in their combined pharmaceutical formulation. The seven methods are ratio difference (RD), isoabsorptive_RD (Iso_RD), amplitude summation (A_Sum), isoabsorptive point, first derivative of the ratio spectra (1DD), mean centering (MCN), and ratio subtraction (RS). On the other hand, RU was determined directly by measuring the absorbance at 358 nm in addition to the two novel Iso_RD and A_Sum methods. The work introduced in this paper aims to compare these different methods, showing the advantages for each and making a comparison of analysis results. The calibration curve is linear over the concentration range of 4–50 μg/mL for AA and RU. The results show the high performance of proposed methods for the analysis of the binary mixture. The optimum assay conditions were established and the proposed methods were successfully applied for the assay of the two drugs in laboratory prepared mixtures and combined pharmaceutical tablets with excellent recoveries. No interference was observed from common pharmaceutical additives.

scholarly journals H-Point Standard Addition Method for Simultaneous Determination of Eosin and Erytrosine

2011 ◽  
Vol 8 (4) ◽  
pp. 1979-1985 ◽  
Author(s):  
Amandeep Kaur ◽  
Usha Gupta
Keyword(s):  
Binary Mixture ◽  
Simultaneous Determination ◽  
Standard Addition ◽  
Standard Addition Method ◽  
Micellar Media ◽  
Addition Method ◽  
Commercial Products ◽  
Food Dyes ◽  
Triton X

A new, simple, sensitive and selectiveH-point standard addition method (HPSAM) has been developed for resolving binary mixture of food colorants eosin and erythrosine, which show overlapped spectra. The method is based on the complexation of food dyes eosin and erythrosine with Fe(III) complexing reagent at pH 5.5 and solubilizing complexes in triton x-100 micellar media. Absorbances at the two pairs of wavelengths, 540 and 550 nm (when eosin acts as analyte) or 518 and 542 nm (when erythrosine act as analyte) were monitored. This method has satisfactorily been applied for the determination of eosin and erythrosine dyes in synthetic mixtures and commercial products.

scholarly journals Spectrophotometric determination of trace iron(III) in natural water after its preconcentration with a chelating resin

2002 ◽  
Vol 67 (10) ◽  
pp. 669-676 ◽  
Author(s):  
Zenovia Moldovan ◽  
Eleonora-Ana Neagu
Keyword(s):  
Ascorbic Acid ◽  
Spectrophotometric Determination ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Standard Addition ◽  
Chelating Resin ◽  
Addition Method ◽  
Strong Base ◽  
Phenanthroline Complex

A method for the determination of Fe(III) at trace levels is described. Thus prior to the spectrophotometric determination, a preconcentration of the trace amounts of iron(III) using a chelate forming resin is proposed. A strong base anion-exchange resin (Dowex 2X4) loaded with Ferron (7-iodo-8-hydroxyquinoline-5-sulphonic acid) was used for Fe(III) preconcentration, at pH 2.2. After desorption with 5% ascorbic acid in 0.5 M HCl, the analyze (converted from Fe(III) to Fe(II) was determined spectrophotometrically at 510 nm as Fe(II)-o-phenanthroline complex. The accuracy of the proposed method was verified by comparing the obtained results with those obtained using AAS with the standard addition method. The sensitivity of the spectrophotometric method (after preconcentration) was 0.01?g Fe(III)/ml. The recovery for iron(III) at the 7?g/l level was 97%.

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