Voltametrické stanovení diacetylu a pyruvátu pomocí derivatizace s o-fenylendiaminem

• Main Author: Kotasová, Marcela
• Other Authors: Vyskočil, Vlastimil
• Format: Dissertation
• Language: Czech
• Published: 2015
• Online Access: http://www.nusl.cz/ntk/nusl-333526

The aim of this Diploma Thesis was to develop sensitive, inexpensive, and less time- consuming voltammetric methods for the determination of diacetyle and pyruvate, when both analytes are derivatized by o­fenylendiamine (OPDA) and the resulting reaction products are determined. For this purpose, techniques DC voltammetry (DCV) and differential pulse voltammetry (DPV) at a mercury meniscus modified silver solid amalgam electrode (m- AgSAE) were used. The optimization consisted of finding a suitable medium and regeneration of the electrode surface for the determination 2,3­dimethylquinoxaline (2,3­DMQ) and 2­hydroxy­methylquinoxaline (2­OH­3­MQ), products of derivatization reactions. The optimal medium for the 2,3­DMQ determination was a solution of the Britton-Robinson buffer (BR­buffer) of pH 6.0 for DCV (optimal regeneration potentials Ein = ­400 mV and Efin = ­900 mV, with limit of quantification LQ ≈ 1.2·10-6 mol·L-1 ) and pH 7.0 for DPV (Ein = ­200 mV and Efin = -900 mV, LQ ≈ 1.1·10-7 mol·L-1 ). For 2­OH­3­MQ, the optimal medium was BR­buffer of pH 4.0 and regeneration potentials Ein = ­500 mV and Efin = ­900 mV for both techniques (LQ ≈ 4.8·10-7 mol·L­1 for DCV and 3,4·10-7 mol·L-1 for DPV). Optimization of derivatization reactions for the determination of diacetyle and pyruvate consisted of...