TY  - JOUR
AU  - Pastor, Ferenc
AU  - Milovanović, Gordana A.
AU  - Todorović, Marija B.
PY  - 2008
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/918
AB  - 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) mol L-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. (C) 2007 Elsevier B.V. All rights reserved.
PB  - Elsevier Science Bv, Amsterdam
T2  - Talanta
T1  - Kinetic method for the determination of traces of thyroxine by its catalytic effect on the Mn(III) metaphosphate-As (III) reaction
VL  - 74
IS  - 5
SP  - 1556
EP  - 1561
DO  - 10.1016/j.talanta.2007.09.033
ER  - 

@article{
author = "Pastor, Ferenc and Milovanović, Gordana A. and Todorović, Marija B.",
year = "2008",
abstract = "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) mol L-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. (C) 2007 Elsevier B.V. All rights reserved.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Talanta",
title = "Kinetic method for the determination of traces of thyroxine by its catalytic effect on the Mn(III) metaphosphate-As (III) reaction",
volume = "74",
number = "5",
pages = "1556-1561",
doi = "10.1016/j.talanta.2007.09.033"
}

Pastor, F., Milovanović, G. A.,& Todorović, M. B.. (2008). Kinetic method for the determination of traces of thyroxine by its catalytic effect on the Mn(III) metaphosphate-As (III) reaction. in Talanta
Elsevier Science Bv, Amsterdam., 74(5), 1556-1561.
https://doi.org/10.1016/j.talanta.2007.09.033

Pastor F, Milovanović GA, Todorović MB. Kinetic method for the determination of traces of thyroxine by its catalytic effect on the Mn(III) metaphosphate-As (III) reaction. in Talanta. 2008;74(5):1556-1561.
doi:10.1016/j.talanta.2007.09.033 .

Pastor, Ferenc, Milovanović, Gordana A., Todorović, Marija B., "Kinetic method for the determination of traces of thyroxine by its catalytic effect on the Mn(III) metaphosphate-As (III) reaction" in Talanta, 74, no. 5 (2008):1556-1561,
https://doi.org/10.1016/j.talanta.2007.09.033 . .

TY  - JOUR
AU  - Milovanović, Gordana A.
AU  - Pastor, Ferenc
AU  - Petkovic, GM
AU  - Todorović, Marija B.
PY  - 2004
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/563
AB  - The kinetics of the iodide-catalyzed Mn(III) metaphosphate-As(III) 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 calculated. The dependence of the reaction rate on temperature was investigated and the energy of activation and other kinetic parameters determined. Iodide was determined under the optimal experimental conditions in the range 0.6-2.5 ng.mL(-1) with a relative standard deviation of up to 6.7% and a detection limit of 0.12 ng mL(-1). The effect of foreign ions on the accuracy of the determinations was also investigated.
PB  - Springer-Verlag Wien, Vienna
T2  - MICROCHIMICA ACTA
T1  - Kinetic determination of iodide traces based on the manganese(III) metaphosphate-arsenic(III) reaction in the presence of orthophosphoric acid
VL  - 144
IS  - 1-3
SP  - 51
EP  - 56
DO  - 10.1007/s00604-003-0100-7
ER  - 

@article{
author = "Milovanović, Gordana A. and Pastor, Ferenc and Petkovic, GM and Todorović, Marija B.",
year = "2004",
abstract = "The kinetics of the iodide-catalyzed Mn(III) metaphosphate-As(III) 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 calculated. The dependence of the reaction rate on temperature was investigated and the energy of activation and other kinetic parameters determined. Iodide was determined under the optimal experimental conditions in the range 0.6-2.5 ng.mL(-1) with a relative standard deviation of up to 6.7% and a detection limit of 0.12 ng mL(-1). The effect of foreign ions on the accuracy of the determinations was also investigated.",
publisher = "Springer-Verlag Wien, Vienna",
journal = "MICROCHIMICA ACTA",
title = "Kinetic determination of iodide traces based on the manganese(III) metaphosphate-arsenic(III) reaction in the presence of orthophosphoric acid",
volume = "144",
number = "1-3",
pages = "51-56",
doi = "10.1007/s00604-003-0100-7"
}

Milovanović, G. A., Pastor, F., Petkovic, G.,& Todorović, M. B.. (2004). Kinetic determination of iodide traces based on the manganese(III) metaphosphate-arsenic(III) reaction in the presence of orthophosphoric acid. in MICROCHIMICA ACTA
Springer-Verlag Wien, Vienna., 144(1-3), 51-56.
https://doi.org/10.1007/s00604-003-0100-7

Milovanović GA, Pastor F, Petkovic G, Todorović MB. Kinetic determination of iodide traces based on the manganese(III) metaphosphate-arsenic(III) reaction in the presence of orthophosphoric acid. in MICROCHIMICA ACTA. 2004;144(1-3):51-56.
doi:10.1007/s00604-003-0100-7 .

Milovanović, Gordana A., Pastor, Ferenc, Petkovic, GM, Todorović, Marija B., "Kinetic determination of iodide traces based on the manganese(III) metaphosphate-arsenic(III) reaction in the presence of orthophosphoric acid" in MICROCHIMICA ACTA, 144, no. 1-3 (2004):51-56,
https://doi.org/10.1007/s00604-003-0100-7 . .