TY  - JOUR
AU  - Milovanović, GA
AU  - Čakar, Mira
AU  - Vucić, NB
AU  - Jokanović, M
PY  - 2000
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/240
AB  - In this work it was established that, in the presence of ammonium carbonate, traces of manganese(II) catalyse the oxidation of Nile Blue A by hydrogen peroxide, which enables its: kinetic determination in the concentration range from 6.6 to 65.9 ng cm(-3), the detection limit being 8.0 x 10(-2) ng cm(-3). Antiviral/antitumour substances modify the catalytic activity of manganese (TT): 1-beta -D-ribofuranosyl-1,2,4-triazole-3-carboxamide, ribavirin, increases the catalytic effect of manganese(II), while 2-beta -D-ribofuranosyl-thiazole-4-carboxamide, tiazofurin, acts as an inhibitor. On the basis of these effects, a kinetic method for determining ribavirin concentrations from 0.5 x 10(-1) to 4.0 x 10(-1) mug cm(-3) and tiazofurin concentrations from 0.3 to 2.6 mug cm(-3) is proposed. The kinetics of the indicator reaction were studied ill the presence of the substances examined, the kinetic equations established, and the constants of the corresponding reaction rates calculated. The effect of temperature on these reactions was also investigated. The method was applied to the determination of manganese(II) in mineral water and ribavirin in pharmaceutical preparations.
PB  - Springer-Verlag Wien, Vienna
T2  - Mikrochimica Acta
T1  - Selective indicator reaction for kinetic determination of traces of manganese(II), ribavirin and tiazofurin
VL  - 135
IS  - 3-4
SP  - 173
EP  - 178
DO  - 10.1007/s006040070007
ER  - 

@article{
author = "Milovanović, GA and Čakar, Mira and Vucić, NB and Jokanović, M",
year = "2000",
abstract = "In this work it was established that, in the presence of ammonium carbonate, traces of manganese(II) catalyse the oxidation of Nile Blue A by hydrogen peroxide, which enables its: kinetic determination in the concentration range from 6.6 to 65.9 ng cm(-3), the detection limit being 8.0 x 10(-2) ng cm(-3). Antiviral/antitumour substances modify the catalytic activity of manganese (TT): 1-beta -D-ribofuranosyl-1,2,4-triazole-3-carboxamide, ribavirin, increases the catalytic effect of manganese(II), while 2-beta -D-ribofuranosyl-thiazole-4-carboxamide, tiazofurin, acts as an inhibitor. On the basis of these effects, a kinetic method for determining ribavirin concentrations from 0.5 x 10(-1) to 4.0 x 10(-1) mug cm(-3) and tiazofurin concentrations from 0.3 to 2.6 mug cm(-3) is proposed. The kinetics of the indicator reaction were studied ill the presence of the substances examined, the kinetic equations established, and the constants of the corresponding reaction rates calculated. The effect of temperature on these reactions was also investigated. The method was applied to the determination of manganese(II) in mineral water and ribavirin in pharmaceutical preparations.",
publisher = "Springer-Verlag Wien, Vienna",
journal = "Mikrochimica Acta",
title = "Selective indicator reaction for kinetic determination of traces of manganese(II), ribavirin and tiazofurin",
volume = "135",
number = "3-4",
pages = "173-178",
doi = "10.1007/s006040070007"
}

Milovanović, G., Čakar, M., Vucić, N.,& Jokanović, M.. (2000). Selective indicator reaction for kinetic determination of traces of manganese(II), ribavirin and tiazofurin. in Mikrochimica Acta
Springer-Verlag Wien, Vienna., 135(3-4), 173-178.
https://doi.org/10.1007/s006040070007

Milovanović G, Čakar M, Vucić N, Jokanović M. Selective indicator reaction for kinetic determination of traces of manganese(II), ribavirin and tiazofurin. in Mikrochimica Acta. 2000;135(3-4):173-178.
doi:10.1007/s006040070007 .

Milovanović, GA, Čakar, Mira, Vucić, NB, Jokanović, M, "Selective indicator reaction for kinetic determination of traces of manganese(II), ribavirin and tiazofurin" in Mikrochimica Acta, 135, no. 3-4 (2000):173-178,
https://doi.org/10.1007/s006040070007 . .

TY  - JOUR
AU  - Čakar, Mira
AU  - Vasić, Vesna
AU  - Petkovska, LT
AU  - Stojić, DL
AU  - Avramov-Ivić, M
AU  - Milovanović, GA
PY  - 1999
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/218
AB  - Newly synthesized oximes, mono and bis imidazole derivatives, which promise to be more effective acetylcholinesterase reactivators than standard antidotes used, were investigated by spectrophotometric and electrochemical methods. The electrochemical investigations confirmed the existence of overlapping equilibria, obtained by spectrophotometric methods. Dissociation constants of those oximes were also obtained by numerical treatment of overlapping equilibria, using the Lavendberg-Marquardt least square method, and when compared with the same for some similar compounds, were found to be very effective acetylcholinesterase reactivators. The distribution of ionic forms of the investigated oximes, as a dependence of pH values, was calculated from the obtained values of dissociation constants. The results indicated that many oxime anions will be available at physiological pH 7.4 and a relative increased ability to reactivate inhibited acetylcholinesterase could be expected.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Spectrophotometric and electrochemical study of protolytic equilibria of some oximes-acetylcholinesterase reactivators
VL  - 20
IS  - 4
SP  - 655
EP  - 662
DO  - 10.1016/S0731-7085(99)00056-4
ER  - 

@article{
author = "Čakar, Mira and Vasić, Vesna and Petkovska, LT and Stojić, DL and Avramov-Ivić, M and Milovanović, GA",
year = "1999",
abstract = "Newly synthesized oximes, mono and bis imidazole derivatives, which promise to be more effective acetylcholinesterase reactivators than standard antidotes used, were investigated by spectrophotometric and electrochemical methods. The electrochemical investigations confirmed the existence of overlapping equilibria, obtained by spectrophotometric methods. Dissociation constants of those oximes were also obtained by numerical treatment of overlapping equilibria, using the Lavendberg-Marquardt least square method, and when compared with the same for some similar compounds, were found to be very effective acetylcholinesterase reactivators. The distribution of ionic forms of the investigated oximes, as a dependence of pH values, was calculated from the obtained values of dissociation constants. The results indicated that many oxime anions will be available at physiological pH 7.4 and a relative increased ability to reactivate inhibited acetylcholinesterase could be expected.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Spectrophotometric and electrochemical study of protolytic equilibria of some oximes-acetylcholinesterase reactivators",
volume = "20",
number = "4",
pages = "655-662",
doi = "10.1016/S0731-7085(99)00056-4"
}

Čakar, M., Vasić, V., Petkovska, L., Stojić, D., Avramov-Ivić, M.,& Milovanović, G.. (1999). Spectrophotometric and electrochemical study of protolytic equilibria of some oximes-acetylcholinesterase reactivators. in Journal of Pharmaceutical and Biomedical Analysis
Pergamon-Elsevier Science Ltd, Oxford., 20(4), 655-662.
https://doi.org/10.1016/S0731-7085(99)00056-4

Čakar M, Vasić V, Petkovska L, Stojić D, Avramov-Ivić M, Milovanović G. Spectrophotometric and electrochemical study of protolytic equilibria of some oximes-acetylcholinesterase reactivators. in Journal of Pharmaceutical and Biomedical Analysis. 1999;20(4):655-662.
doi:10.1016/S0731-7085(99)00056-4 .

Čakar, Mira, Vasić, Vesna, Petkovska, LT, Stojić, DL, Avramov-Ivić, M, Milovanović, GA, "Spectrophotometric and electrochemical study of protolytic equilibria of some oximes-acetylcholinesterase reactivators" in Journal of Pharmaceutical and Biomedical Analysis, 20, no. 4 (1999):655-662,
https://doi.org/10.1016/S0731-7085(99)00056-4 . .

TY  - JOUR
AU  - Milovanović, Gordana
AU  - Petronijević, Radivoj
AU  - Čakar, Mira
PY  - 1998
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/177
AB  - A kinetic method for the determination of selenium(IV) traces is proposed, based on its inhibitory action on the oxidation of Nile Blue A by hydrogen peroxide in phosphate buffer (pH 10.5). A linear dependence was established between the rate of the proposed indicator reaction and selenium concentration in the range 9.5 x 10(-2)-1.58 ng cm(-3). The experimental conditions of maximal selenium effect were established. Selenium, determined by the tangent method, was determined at concentrations over the range 0.22-1.26 ng cm(-3), with relative standard deviations up to 4.5%. The reaction rate was followed spectrophotometrically. The effect of foreign ions on the accuracy of this method was also investigated. The method was applied to the determination of selenium in pharmaceutical preparations and wheat flour.
PB  - Springer-Verlag Wien, Vienna
T2  - Mikrochimica Acta
T1  - Kinetic determination of trace levels of selenium(IV) and total selenium by Nile Blue A hydrogen peroxide method
VL  - 128
IS  - 1-2
SP  - 43
EP  - 48
DO  - 10.1007/BF01242188
ER  - 

@article{
author = "Milovanović, Gordana and Petronijević, Radivoj and Čakar, Mira",
year = "1998",
abstract = "A kinetic method for the determination of selenium(IV) traces is proposed, based on its inhibitory action on the oxidation of Nile Blue A by hydrogen peroxide in phosphate buffer (pH 10.5). A linear dependence was established between the rate of the proposed indicator reaction and selenium concentration in the range 9.5 x 10(-2)-1.58 ng cm(-3). The experimental conditions of maximal selenium effect were established. Selenium, determined by the tangent method, was determined at concentrations over the range 0.22-1.26 ng cm(-3), with relative standard deviations up to 4.5%. The reaction rate was followed spectrophotometrically. The effect of foreign ions on the accuracy of this method was also investigated. The method was applied to the determination of selenium in pharmaceutical preparations and wheat flour.",
publisher = "Springer-Verlag Wien, Vienna",
journal = "Mikrochimica Acta",
title = "Kinetic determination of trace levels of selenium(IV) and total selenium by Nile Blue A hydrogen peroxide method",
volume = "128",
number = "1-2",
pages = "43-48",
doi = "10.1007/BF01242188"
}

Milovanović, G., Petronijević, R.,& Čakar, M.. (1998). Kinetic determination of trace levels of selenium(IV) and total selenium by Nile Blue A hydrogen peroxide method. in Mikrochimica Acta
Springer-Verlag Wien, Vienna., 128(1-2), 43-48.
https://doi.org/10.1007/BF01242188

Milovanović G, Petronijević R, Čakar M. Kinetic determination of trace levels of selenium(IV) and total selenium by Nile Blue A hydrogen peroxide method. in Mikrochimica Acta. 1998;128(1-2):43-48.
doi:10.1007/BF01242188 .

Milovanović, Gordana, Petronijević, Radivoj, Čakar, Mira, "Kinetic determination of trace levels of selenium(IV) and total selenium by Nile Blue A hydrogen peroxide method" in Mikrochimica Acta, 128, no. 1-2 (1998):43-48,
https://doi.org/10.1007/BF01242188 . .

TY  - JOUR
AU  - Milovanović, G.A
AU  - Čakar, Mira
AU  - Petronijević, R.B
PY  - 1997
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/164
AB  - A kinetic method for the determination of selenium(IV) in ethanol solution is proposed. The method is based on the action of selenium(IV) upon the oxidation of Nile Blue A by hydrogen peroxide in the presence of phosphate buffer (pH 10.8). The reaction rate was followed spectrophotometrically at 637.5 nm. It was established that the action of selenium(IV) on the indicator reaction is maximal with a 0.25% ethanol solution. The kinetic expression for the reaction in the presence and absence of selenium(IV) are postulated. Optimal experimental conditions for the determination of selenium(IV) were established and selenium(IV) was determined in concentrations from 0.95×10 -2 to 12.6×10 -2 ng cm -3 , with a relative standard deviation of 5.2% A lower detection limit (1.6×10 -3 ng cm -3 ) and higher selectivity compared to the determination in aqueous solution are obtained. The method was applied for the determination of selenium(IV) in mineral water.
PB  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - A kinetic method for the determination of selenium(IV) in ethanol solution
VL  - 62
IS  - 8
SP  - 677
EP  - 681
UR  - https://hdl.handle.net/21.15107/rcub_farfar_164
ER  - 

@article{
author = "Milovanović, G.A and Čakar, Mira and Petronijević, R.B",
year = "1997",
abstract = "A kinetic method for the determination of selenium(IV) in ethanol solution is proposed. The method is based on the action of selenium(IV) upon the oxidation of Nile Blue A by hydrogen peroxide in the presence of phosphate buffer (pH 10.8). The reaction rate was followed spectrophotometrically at 637.5 nm. It was established that the action of selenium(IV) on the indicator reaction is maximal with a 0.25% ethanol solution. The kinetic expression for the reaction in the presence and absence of selenium(IV) are postulated. Optimal experimental conditions for the determination of selenium(IV) were established and selenium(IV) was determined in concentrations from 0.95×10 -2 to 12.6×10 -2 ng cm -3 , with a relative standard deviation of 5.2% A lower detection limit (1.6×10 -3 ng cm -3 ) and higher selectivity compared to the determination in aqueous solution are obtained. The method was applied for the determination of selenium(IV) in mineral water.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "A kinetic method for the determination of selenium(IV) in ethanol solution",
volume = "62",
number = "8",
pages = "677-681",
url = "https://hdl.handle.net/21.15107/rcub_farfar_164"
}

Milovanović, G.A, Čakar, M.,& Petronijević, R.B. (1997). A kinetic method for the determination of selenium(IV) in ethanol solution. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 62(8), 677-681.
https://hdl.handle.net/21.15107/rcub_farfar_164

Milovanović G, Čakar M, Petronijević R. A kinetic method for the determination of selenium(IV) in ethanol solution. in Journal of the Serbian Chemical Society. 1997;62(8):677-681.
https://hdl.handle.net/21.15107/rcub_farfar_164 .

Milovanović, G.A, Čakar, Mira, Petronijević, R.B, "A kinetic method for the determination of selenium(IV) in ethanol solution" in Journal of the Serbian Chemical Society, 62, no. 8 (1997):677-681,
https://hdl.handle.net/21.15107/rcub_farfar_164 .