A Simple Strategy for Simultaneous Determination of Paracetamol and Caffeine Using Flow Injection Analysis with Multiple Pulse Amperometric Detection

In this work, we report a simple and novel strategy for simultaneous analysis using flow injection analysis with multiple pulse amperometric (FIA‐MPA) detection. The proposed strategy was successfully used for simultaneous determination of paracetamol and caffeine (model analytes) in pharmaceutical formulations. A sequence of potential pulses (waveform) was selected in such a way that PA is selectively oxidized at E₁ (+1.20 V/50 ms) and both compounds (PA+CA) are simultaneously oxidized at E₂ (+1.55 V/50 ms); hence, current subtraction (using a correction factor) can be used for the selective determination of CA. The proposed FIA method is simple, cheap, fast (140 injections h^?1), and present selectivity for the determination of both compounds in pharmaceutical samples, with results similar to those obtained by HPLC at a 95 % confidence level.