Vedecký časopis

50 2011

Journal of Food and Nutrition Research
Súhrny čísla 4 / 2011

Non-isothermal kinetics of benzo[a]pyrene photooxidation in glyceryl trioctanoate at various heating rates
Journal of Food and Nutrition Research, 50, 2011, č. 4, s. 249-253

Peter Šimon, Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK–812 37 Bratislava, Slovakia. E-mail: peter.simon@stuba.sk

Súhrn: Benzo[a]pyrene (BaP) was dissolved in glyceryl trioctanoate, heated in a glass reaction vessel within a temperature range of 303.15–473.15 K at the heating rates 0.1, 0.2, 0.5, 1 and 2 K•min 1, respectively, and simultaneously exposed to UV light at the wavelength ? = 365 nm at the radiation power of 20 mW•cm-2 in order to study the decrease of BaP concentration due to its photooxidation. The reaction mixture was sampled at temperature increments of 10 K and the concentration of BaP was determined by HPLC with fluorescence detector. As observed, the BaP concentration decreased from initial 100 µg•l-1 in dependence on the heating rate. From the experimental results, the kinetic parameters of the first-order kinetic equation (A = (2.8 ± 5.9) × 10 14 min-1, D = (5.86 ± 0.43) × 10-2 K-1) describing the kinetics of BaP photooxidation were obtained. Knowing the kinetic parameters, modelling of the photooxidation for any time/temperature regime is feasible without a deeper insight into the mechanism of the process. The advantage of the multiple heating rate approach lies in the fact that a larger part of the kinetic hypersurface is mapped so that the kinetic parameters obtained are more reliable and trustworthy as when obtaining the kinetic parameters just from a single kinetic curve.

Kľúčové slová: polycyclic aromatic hydrocarbons; benzo[a]pyrene; non-isothermal kinetics; HPLC; photooxidation; glyceryl trioctanoate; heating

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