RESUMO
A new system for continuous flow chemiluminescence detection, based on the use of a simple and low-priced lens-free digital camera (with complementary metal oxide semiconductor technology) as a detector, is proposed for the quantitative determination of paracetamol in commercial pharmaceutical formulations. Through the camera software, AVI video files of the chemiluminescence emission are captured and then, using friendly ImageJ public domain software (from National Institutes for Health), properly processed in order to extract the analytical information. The calibration graph was found to be linear over the range 0.01-0.10 mg L-1 and over the range 1.0-100.0 mg L-1 of paracetamol, the limit of detection being 10 µg L-1. No significative interferences were found. Paracetamol was determined in three different pharmaceutical formulations: Termalgin®, Efferalgan® and Gelocatil®. The obtained results compared well with those declared on the formulation label and with those obtained through the official analytical method of British Pharmacopoeia. Graphical abstract Abbreviated scheme of the new chemiluminescence detection system proposed in this paper.