Efficient Enrichment and Analysis of Vicinal-Diol-Containing Flavonoid Molecules Using Boronic-Acid-Functionalized Particles and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Detection and quantitation of flavonoids are relatively difficult compared to those of other small-molecule analytes because flavonoids undergo rapid metabolic processes, resulting in their elimination from the body. Here, we report an efficient enrichment method for facilitating the analysis of vicinal-diol-containing flavonoid molecules using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In our strategy, boronic-acid-functionalized polyacrylamide particles were used, where boronic acids bound to vicinal diols to form boronate monoesters at basic pH. This complex remained intact during the enrichment processes, and the vicinal-diol-containing flavonoids were easily separated by centrifugation and subsequent acidic treatments. The selectivity and limit of detection of our strategy were confirmed by mass spectrometry analysis, and the validity was assessed by performing the detection and quantitation of quercetin in mouse organs

Computational Discovery of Optimal Dopants for Nickel Iron Oxyhydroxide to Enhance OER Activity and Saline Water Compatibility

A strategic approach has been proposed for designing robust, high-performing oxygen evolution reaction (OER) catalysts tailored for saline water splitting. By employing a density functional theory (DFT)-based computational screening process, a set of promising dopants were identified from a range of 26 3d to 5d transition metals, with the aim of enhancing the activity and saline water resilience of the catalysts. The screening methodology was 3-fold, encompassing evaluations of OER energetics, chlorine evolution reaction (ClER) energetics, and chloride-corrosion energetics. The screening led to the selection of Sc as a promising dopant, which substantially elevated the performance of the NiFeOOH catalysts. This improvement was validated by an 87 mV decrease in OER overpotential at 100 mA/cm2 and a 100 h stability test under 1 M KOH + 0.5 M NaCl conditions. This study contributes to the understanding of the alkaline ClER and chloride-corrosion mechanisms, providing insights into catalyst behavior under saline conditions