Determination of 5-nitroindazole using silver solid amalgam electrode

Monatshefte für Chemie - Chemical Monthly - The voltammetric behavior of 5-nitroindazole was investigated at polished (p-AgSAE) and at mercury meniscus-modified (m-AgSAE) silver solid amalgam...     

The oxidation of organic substances with compounds of trivalent manganese: XXII. The oxidation of glyceraldehyde with manganese(III) sulfate

The oxidation of glyceraldehyde with manganese(III) sulfate was studied. The reaction stoichiometry was found and a procedure for an indirect determination of 5–17 mg of the test substance has been proposed. The recommended procedure is based on the oxidation of glyceraldehyde with the reagent, the excess of which is back-titrated with standard solution of ferrous sulfate.     

Coulometric redox titrations of some biologically active thiols with iodine in methanol and bromine in acetic acid

The possibility of coulometric titrations of cysteine, 2-thio-uracil, 6-mercaptopurine, and 6-thioguanine with iodine and bromine in methanol and with bromine in acetic acid has been investigated. Conditions have been found for the direct titration of the test substances with iodine in methanol based on their 1-electron oxidation to the corresponding disulphides and for their direct and indirect determination with bromine in acetic acid based on their 6-electron oxidation to the corresponding sulphonic acids.On leave from Department of Analytical Chemistry, Charles University, Prague, Czechoslovakia     

Oxidation of organic substances by compounds of trivalent manganese : XXV. Determination of benzene polyhydroxy and aminohydroxy derivatives with a standard solution of the fluoride complex of trivalent manganese

The redox potential of the Mn(III)/Mn(II) system in a medium of potassium fluoride and sulfuric acid was measured and its dependence on the concentration of both substances was found. Furthermore, the influence of the concentration of potassium fluoride and sulfuric acid on the visible absorption spectrum of trivalent manganese was studied.     

The use of redox reactions in the analysis of dyes and dye intermediates: XIV. Direct current polarography of 4,4′-disubstituted azobenzenes in acetonitrile

The polarographic reduction of some 4,4′-disubstituted azobenzenes in an acetonitrile medium was studied. The diffusion character of the observed limiting currents was confirmed and a mechansim of polarographic reduction proposed. The possibility of analytical application is briefly discussed.     

Application of Non‐Stop‐Flow Differential Pulse Voltammetry at a Tubular Detector of Silver Solid Amalgam for Electrochemical Determination of Lomustine (CCNU)

An application of the flow differential pulse voltammetry with tubular detector based on silver solid amalgam for determination of antineoplastic drug lomustine in pharmaceutical preparations is presented. The highest sensitivity was obtained in [0.10 mol dm^?3 MES; 2.00 mol dm^?3 NaCl; pH 6.0]:EtOH (9 : 1) with flow rate 0.50 mL min^?1, and the magnitude of the modulation amplitude ?0.070 V. The calibration dependence was linear in the range 1×10^?6–1 × 10^?4 mol dm^?3 (R²=0.999). The limit of detection was 1.5×10^?7 mol dm^?3. This method was successfully used for determination of lomustine in real samples of chemotherapy drug CeeNU Lomustine 40 mg.