Thermal decomposition of tert‐butyl peroxide in a gas chromatographic reactor: A comparison of kinetic approaches

Abstract

The thermal decomposition of tert-butyl peroxide is investigated utilizing both the column and the injection port of a commercial gas chromatograph (GC) as chemical reactors. Using the injector liner as the reactor, the chromatographic peak areas of the reactant, measured at various injector temperatures, are used in the determination of the activation energy of the decomposition (E a ). With the column serving as the reactor, both the reactant peak areas and the product peak shapes are similarly utilized for this purpose. Values of E a obtained using different mathematical treatments for each of the three approaches are found to range from 115 to 164 kJ/mol. Of these methods, the column reactor approach utilizing peak area measurements (referred to as PACR, for "peak area, column reactor") is found to be far superior in terms of its speed, robustness, and its accuracy in determining E a . The PACR method's effectiveness can be largely attributed to the mathematical treatment that is described in the approach. C

An HPLC chromatographic reactor approach for investigating the hydrolytic stability of a pharmaceutical compound

“…(5), highlighted by this work, is that only a ∼3% conversion allows one to extract a reasonable estimate for the activation energy from the kinetic data (using the integrated Aprepitant peak areas, which proved problematic in the quiescent solution experiment described earlier-see Fig. 4), which represents a significant improvement over other chromatographic reactor treatments, especially those which model the peak shapes instead of peak areas [5].…”

“…(5) has previously been utilized only for GCR applications [5][6][7][8]. This is because the derivation of the equation was originally based on assumptions pertaining to an ideal column reactor (ICR).…”

“…Previously, Langer showed that for HPLC reactors, reaction rates should ideally be between 10 −2 and 10 −4 s −1 in order to use the column as a reactor for studying the kinetics [3]. Unfortunately, while various mathematical treatments have been used to-date to describe the kinetic data obtained from different types of chromatographic reactors, we have found that many of these approaches may not be optimal, at least in the case of GC applications [5]. Recently, we outlined the development of a new treatment for use with various chromatographic reactors which we hope will facilitate the popularization of the technique [5].…”

“…Unfortunately, while various mathematical treatments have been used to-date to describe the kinetic data obtained from different types of chromatographic reactors, we have found that many of these approaches may not be optimal, at least in the case of GC applications [5]. Recently, we outlined the development of a new treatment for use with various chromatographic reactors which we hope will facilitate the popularization of the technique [5]. This treatment is described below in Section 2 of the paper, as it applies to the chemical system of interest in this work.…”

From Dynamics to Kinetics: Investigation of Interconverting Stereoisomers and Catalyzed Reactions

“…In an effort to overcome these problems, an alumina was used which had been treated with a solution of 10% KOH in methanol to neutralize the very strongly acidic sites attributed to the nonlinear isotherm. When Skrdla [56] compared the thermal decomposition of tert-butyl peroxide in the gas chromatograph injector and also on the separation column, the measurements were performed at different temperatures and the activation energies calculated and compared with different kinetic models.…”