Qualitative and quantitative determination and comparison of caffeine, theobromine and theophylline in xanthine alkaloids containing products

K. Lukas Master‘s thesis. Supervisor Doc. dr. Asta Kubilienė 2018–2020 yrs.; Lithuanian University of Health Sciences, Medical Academy, Faculty of Pharmacy, Department of Analytical and Toxicological Chemistry – Kaunas. The title: Qualitative and quantitative determination and comparison of caffeine, theobromine and theophylline in xanthine alkaloid containing products. The aim: Perform qualitative and quantitative determination of caffeine, theobromine and theophylline in different xanthine group alkaloids containing products by high performance liquid chromatography and compare the obtained results. The objectives of the research: Perform qualitative and quantative determination of caffeine, theobromine and theophylline in dried coffee berries tea samples, instant coffee and cocoa beans samples by high performance liquid chromatography. Determine the effect of extractant on the content of caffeine, theobromine and theophylline in dried coffee berries tea, instant coffee and cocoa beans samples. Evaluate the effect of fragmentation on xanthine group alkaloids content in raw cocoa beans samples. Evaluate the influence of roasting time on the content xanthine group alkaloids in cocoa beans samples. Compare the amounts of xanthine group alkaloids found in samples of roasted cocoa beans and raw cocoa beans by roasting cocoa beans at different times. The object and methods: Dried coffee berries tea, raw cocoa beans (fragmentated and non fragmentated), roasted cocoa beans, instant coffee. During this research the method of high performance liquid chromatography was chosen for qualitative and quantitative analysis of materials. Results and conclusions: Caffeine, theobromine and theophylline were qualitatively detected in dried coffee berries tea samples and instant coffee, caffeine and theobromine were detected in cocoa beans samples by using high performance liquid chromatography method. The highest (388,34 ± 7,22 μg/ml) caffeine content was determined by extracting dried coffee berries tea preparations by 70 % ethanol, the highest (p