Development and evaluation of microscale apparatus for the generation of kinetic data at high temperatures, applied to the degradation of thiamine

Abstract

A microminiaturized tubular heating system, with continuous heating and cooling, for kinetic studies has been developed. The apparatus was used in the temperature range from 110 to 160 °C. Heating to holding temperature and cooling to room temperature was accomplished in one second. The sample was injected into the apparatus with an HPLC loop injector. After thermal treatment, a well-defined fraction was withdrawn by a fraction collector. The sample dilution during thermal processing was corrected against an inert standard. A kinetic study of thiamine degradation in phosphate buffer at pH 7 was performed to evaluate the apparatus. The activation energy ( E a) of the thermal degradation of thiamine was determined to be 119 kJ mol ( r = −0.9981).