| Kinetic method for the determination of traces of thyroxine by its catalytic effect on the Mn(III) metaphosphate-As(III) reaction. | |
| | |
MedLine Citation:
|
PMID: 18371817 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
A new, highly sensitive and simple kinetic method for the determination of thyroxine was proposed. The method was based on the catalytic effect of thyroxine on the oxidation of As(III) by Mn(III) metaphosphate. The kinetics of the reaction was studied in the presence of orthophosphoric acid. The reaction rate was followed spectrophotometrically at 516 nm. It was established that orthophosphoric acid increased the reaction rate and that the extent of the non-catalytic reaction was extremely small. A kinetic equation was postulated and the apparent rate constant was calculated. The dependence of the reaction rate on temperature was investigated and the energy of activation and other kinetic parameters were determined. Thyroxine was determined under the optimal experimental conditions in the range 7.0 x 10(-9) to 3.0 x 10(-8) mol L(-1) with a relative standard deviation up to 6.7% and a detection limit of 2.7 x 10(-9) molL(-1). In the presence of 0.08 mol L(-1) chloride, the detection limit decreased to 6.6 x 10(-10) mol L(-1). The proposed method was applied for the determination of thyroxine in tablets. The accuracy of the method was evaluated by comparison with the HPLC method. |
| | |
Authors:
|
Ferenc T Pastor; Gordana A Milovanović; Marija Todorović |
Related Documents
:
|
4023277 - Substoichiometric determination of cobalt in crud. 18965457 - Column chromatographic preconcentration of palladium in alloys with 9,10 phenanthrenequ... 16458577 - Indirect spectrophotometric determination of arbutin, whitening agent through oxidation... 18968957 - Determination of ethanol in beverages by flow injection, pervaporation and density meas... 22445847 - Nanographene-based tyrosinase biosensor for rapid detection of bisphenol a. 15830947 - Determination of l-carnitine in food supplement formulations using ion-pair chromatogra... |
Publication Detail:
|
Type: Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't Date: 2007-10-02 |
Journal Detail:
|
Title: Talanta Volume: 74 ISSN: 1873-3573 ISO Abbreviation: Talanta Publication Date: 2008 Feb |
Date Detail:
|
Created Date: 2008-03-28 Completed Date: 2008-04-30 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 2984816R Medline TA: Talanta Country: England |
Other Details:
|
Languages: eng Pagination: 1556-61 Citation Subset: IM |
Affiliation:
|
Faculty of Chemistry, University of Belgrade, P.O. Box 158, 11001 Belgrade, Studentski trg 12-16, Serbia. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Arsenic
/
chemistry Catalysis Kinetics Manganese / chemistry Phosphoric Acids Phosphorous Acids / chemistry Spectrum Analysis Tablets / analysis Temperature Thyroxine / analysis* |
| Chemical | |
Reg. No./Substance:
|
0/Phosphoric Acids; 0/Phosphorous Acids; 0/Tablets; 10343-62-1/metaphosphoric acid; 7439-96-5/Manganese; 7440-38-2/Arsenic; 7488-70-2/Thyroxine; 7664-38-2/phosphoric acid |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Evaluation of semiquantitative analysis mode in ICP-MS.
Next Document: Comparison between the electrocatalytic properties of different metal ion phthalocyanines and porphy...