Coupled monolithic columns as an alternative for the use of viscous ethanol–water mobile phases on chromatographic fingerprinting complex samples

Reaction of the Phytochemistry Community to Green Chemistry: Insights Obtained Since 1990

“…Strategies i and ii were employed successfully to replace MeOH and CH 3 CN with EtOH in HPLC-PAD/UV fingerprinting studies of Casearia sylvestris, Bauhinia forficata, Bidens pilosa, Cynara scolynus, and Glycine max, 2,15,100,118 whereas strategy iii was explored for the metabolite profiling of Lippia sidoides. 119 Recent studies have demonstrated that even inexpensive food-grade bioethanol obtained from fermentation processes of sugar cane can be used in UHPLC-PAD/UV metabolite profiling of Eugenia uniflora and propolis from Baccharis dracunculifolia, with an efficiency superior to reference methods, while reducing the environmental impact of chromatographic analysis. 96,120 Even if MS grade EtOH is not yet commercially available, it could become a reality if natural product scientists demand that fine chemical companies offer it.…”

“…At least three strategies have been adopted to circumvent the high viscosities of EtOH–H 2 O mixtures: (i) reducing the mobile phase flow rate during the analysis to be compatible with the maximum back-pressure afforded by a standard HPLC instrument, while approaching optimal flow rates (higher efficiencies); (ii) preheating the mobile (and stationary) phases to decrease their viscosity; and (iii) employing coupled monolithic columns rather than packed ones. Strategies i and ii were employed successfully to replace MeOH and CH 3 CN with EtOH in HPLC-PAD/UV fingerprinting studies of Casearia sylvestris , Bauhinia forficata , Bidens pilosa , Cynara scolynus , and Glycine max , ,,, whereas strategy iii was explored for the metabolite profiling of Lippia sidoides . Recent studies have demonstrated that even inexpensive food-grade bioethanol obtained from fermentation processes of sugar cane can be used in UHPLC-PAD/UV metabolite profiling of Eugenia uniflora and propolis from Baccharis dracunculifolia , with an efficiency superior to reference methods, while reducing the environmental impact of chromatographic analysis. , Even if MS grade EtOH is not yet commercially available, it could become a reality if natural product scientists demand that fine chemical companies offer it.…”