Journal of Pharmaceutical and Biomedical Analysis Open · Published 2025-11-20 · DOI 10.1016/j.jpbao.2025.100096
This work reports an analytical strategy for the quantification of pyridoxine (PYR) and caffeine (CAF) in pre-workout formulations, specifically multi-ingredient performance supplements (MIPS) and encapsulated guarana powder (GP). The approach relies on batch injection analysis with amperometric detection (BIA-AD) employing a boron-doped diamond electrode (BDDE) as the working electrode. A straightforward correction factor (CF) was applied to enable caffeine determination at + 1.5 V in the presence of pyridoxine. The method provided low limits of quantification, 9.64 µmol L−1 for pyridoxine and 6.82 µmol L−1 for caffeine. Accuracy was assessed through spiking and recovery assays, yielding values between 90 % and 110 %, and the results showed good agreement with those obtained by the reference High-Performance Liquid Chromatography with Diode-Array Detection technique. Application of the method to real samples demonstrated that both analytes were successfully measured in multi-ingredient performance supplements. For guarana powder samples, the caffeine concentrations were consistent with the labeled values. Overall, the method offers a rapid, low-cost, portable, and environmentally sustainable alternative for the determination of pyridoxine and caffeine in pre-workout supplements.
Abstract from DOAJ. Public domain (CC0 1.0).
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