Affiliation: Federal University of Rio Grande do Norte, Institute of Chemistry, Lagoa Nova - CEP 59.072- 970 – Natal, RN, Brazil.
Caffeine is the oldest consumed psychoactive drug, present in coffee, cocoa, tea, among other products. Several conventional methods are used to analyze caffeine, for example, chromatography and spectrometry, but these methods are expensive when compared to electroanalytical methods. The objective of this study is to study the feasible applicability of electrochemical techniques for quantification of caffeine in medications. Cyclic voltammetry was performed on the platinum electrode in 0.5 M H2SO4 and after that differential pulse voltammetry was performed to obtain the linear relation between caffeine concentration and current. A linear response in the electroanalytical approach exists from 38.05±3.02 to 192.39±1.04 ppm with a limit of detection of about 9.09±0.72 ppm. This sensor may represent a new analytical tool for caffeine analysis, based on existing literature.