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1

Temperature influence on the electrode process in the presence of 6-thioguanine and surfactants

Nosal-Wiercińska Agnieszka, Kaliszczak Waldemar, Martyna Marlena, Szabelska Anna, Gołębiowska Beata, Wiśniewska Małgorzata

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 6

14--21

EN

The measurements concerning the process of the electroreduction of Bi(III) ions in the presence of 6–thioguanine (6TG) and Triton X-100 as well as Tween 80 in the 2 mol·dm-3 chlorates(VII) demonstrate a dependence of the process rate on temperature. The applied electrochemical techniques (DC polarography, cyclic and SWV voltammetry) allowed to determine the kinetic and thermodynamic parameters as well as their correlation with changes in kinetics of the electrode process. The catalytic activity of 6TG was confirmed by the decrease of overall enthalpies of activation. Different values of ∆𝐻# and ∆𝑆° for Bi(III) electroreduction in the presence of 6–thioguanine as well as Triton X-100 and Tween 80 suggest changes in kinetics of the electrode process towards inhibition.

2

Spectrophotometric determination of thiols in pure sub stances and pharmaceutical preparation

Skowron M., Ciesielski W.

Chemia Analityczna

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2009

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Vol. 54, No. 4

743-751

EN

A spectrophotometric method for determination of mesna (MA), 6-mercaptopurine (MP), 6-thioguanine (TG), and 6-propyl-2-thiouracil (PTU) has been developed. The method was based on the reaction of thiouracils with N,N-dimethyi-p-phenylenediamine (DMPD) in acidic solution in the presence of the Fe3++ ion, an oxidising agent. Absorbance of the obtained coloured products was measured at the corresponding optimum wavelengths: 490 nm for MA (ε=1.9x103L mol-1 cm-1), 455 nm for MP (ε = 1.9 x 10-1 I, mol-1 cm-1), 460nmforTG(ε=l.6x 103 L mol cm-1), and 465 nm for PTU (s = 2.l x 10-1L mol-1 cm-1). Beer's law was obeyed in the following concentration ranges: 8.2 x 10-2-9.0 x 10-2 g L-1 for MA, 6.0 x 10-1-3.8x 10-1gL--1forMP,4.2x 1Q-M.2 x 10-2 g L-1 for TG and 4.2 x 10--3--3.9 x 10-2 g L-1 for PTU. The method has been applied for determination of thiols in pharmaceuticals.

PL

Opracowano spektrofotometryczną metodę oznaczania mesny (MA). 6-merkaptopu-ryny (MP), 6-tioguaniny (TG) i 6-propylo-2-tiouracylu (PTU). Metoda W7korzystuje reakcję tiouracyli z N,N-dimetylo-p-fenylenodiamią w środowisku kwaśnym, w obecności jonów Fe+2 jako utleniacza. Absorbancję barwnych produktów reakcji mierzono przy długościach fali K = 490 nm dla MA (e = 1.9 x 103L mol cm-1), X = 455 nm dla MP (E = 1.9 x l05 L mol-1 cm-1), K = 460 nm dla TG (e = 1.6 x l0M, mol-1 cm-1) i X. = 475 nm dla PTU (ε= 2. l x l0-1 L mol-1 cnr')- Prawo Beera jest spełnione w zakresie stężeń 8.2 x &epsilon-9.0x 10-1 g L-1dla MA, 6.0 x 10--13.8x 10-1g L-1dla MP, 4.2 x 10MA.2 x 10'-2 g L-2dla TG and 4.2 x 10-1-3.9 x 1010-2 g L-1 dla PTU. Opracowaną metodę wykorzystano do oznaczaniazwiązków w preparatach farmaceutycznych.

3

Spektrofotometryczna nowa metoda oznaczania palladu(II) za pomocą 6-tioguaniny

Sikorska-Tomicka H., Filipiuk D.

Zeszyty Naukowe Politechniki Białostockiej. Matematyka, Fizyka, Chemia

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1998

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Z. 18

83-90

PL

Opracowano nową metodę oznaczania palladu(II) z zastosowaniem 6-tioguaniny. Oznaczono pallad(II) w zakresie stężenia od 1,0 - 8 mg/cm3 przy pH od 1,0 - 2,0. Badano wpływ obcych jonów na wyniki oznaczania palladu(II). Ustalono skład tworzącego się kompleksu Pd-TG, który wynosi 1 : 2. Opracowaną metodą oznaczono pallad(II) w katalizatorze palladowym.

EN

The reaction of 6-thioguanine (TG) with palladium(II) has been applied in spectrophotometric determination of palladium(II) in a concentration range 1,0 - 8,0 mg/cm3 at optimal range pH 1,0 - 2,0. The effects of substances and ions on the results of the determination was evaluated. The molar ratio of palladium(II) with thioguanine is 1 : 2. The method was used for the determination of palladium(II) in catalyst.