Micah Omare
Joshua Kiprotich Kibet
Jackson K. Cherutoi
Fredrick O. Kengara
Abstract
Herein, we present phenolic reaction products from the thermolysis of khat that is remarkable in the context of smoked khat under conditions that are representative of cigarette smoking. Phenolic compounds occur naturally and some as a result of continuous human activities yielding grave environmental and human health risks. Accordingly, this study investigates the phenolic compounds generated from the thermal degradation of Catha edulis, computes the global energies and entropies of selected phenolic compounds and their derivatives, and performs their geometry optimization using Gaussian computational package. In addition, we report on the elemental speciation of char from khat pyrolysis. The thermal degradation of khat was conducted in an inert nitrogen environment at 1 atmosphere at a contact time of 2s using a quartz tubular reactor. The pyrolysis effluent was characterized using a Gas-chromatograph coupled to a mass spectrometer. The GC-MS results indicated that the khat pyrolysis yielded phenolic compounds including p-cresol, catechol, hydroquinone and other substituted methoxy phenols whose maximum release was attained at temperatures of 450 °C and 550 °C. During khat pyrolysis, phenols displayed an increase in reaction endothermicity with increase in temperature up to temperatures of around 400 °C after which reaction exothermicity is witnessed. It is evident that toxic phenolic compounds are predominantly released from khat pyrolysis and are likely to cause devastating effects in human beings once ingested. Accordingly, campaigns against the smoking of khat should be carried out in efforts to promoting health living standards amongst human beings.
Keywords
khat pyrolysis, phenolic compounds, khat smoke, geometry optimization, molecular geometries
