Eco-friendly and inexpensive food grade bioethanol for Eugenia uniflora L. chromatographic fingerprinting: A trade-off between separation and sustainability

In this work, we developed a green HPLC-PAD method to fingerprint Eugenia uniflora L. leaves by employing Design of Experiments with inexpensive food grade bioethanol as mobile-phase organic modifier aiming to cover Green Analytical Chemistry (GAC) principles and concepts. Initially, two different chromatographic columns coupled with five chromatographic factors were screened employing a Fractional Factorial Design. Once the phenyl-hexyl column was chosen and the most important factors were known, they were optimized in a Central Composite Design (CCD). Outcomes were monitored using two multiparametric responses: Green Chromatographic Fingerprinting Response (GCFR) with modifications and HPLC-EAT (Environmental Assessment Tool), and Derringer's desirability function was employed to reach a trade-off between them. The Response Surface Methodology (RSM) strategy enabled the prediction of the optimized chromatographic conditions as 5.26–52.63 % of the food grade bioethanol (95 °GL) in 30 min, at 35 °C, and 0.6 mL min−1. The simultaneous consideration of environmental and separation parameters led to the successful development of a validated HPLC-PAD method more efficient, cheaper, and almost 3-fold greener when compared with a preliminary reference method reported in the literature, also being applicable even by small laboratories without cutting-edge instrumentation.