Characterization of stationary phases based on monosubstituted benzene retention indices using correspondence factor analysis and linear solvation energy relationships in RPLC

International audienceIn reversed-phase liquid chromatography (RPLC), the comparison of experimental results obtained from different columns is a complex problem. A correspondence factor analysis (CFA) and a linear solvation energy relationship (LSER) were applied on retention data to characterize second-order intermolecular interactions responsible for retention on a set of RPLC columns. Seven octadecyl-C 18 columns with different packing materials are obtained from different manufacturers and one octyl-C 8 column. The retention data were determined under isocratic conditions using a methanol-water (65:35, v/v) mobile phase. The chromatographic retention indices based on alkan-2-ones and alkyl aryl ketones retention index scales are calculated using a multiparametric least-squares regressions iterative method. The CFA and LSER results permitted to highlight that the retention indices were appropriate for studying the second-order retention mechanisms on the eight chromatographic systems investigated and exhibited the best reproducibility. Although many earlier studies have reported the use of chemo-metric methods to characterize chemical factors affecting retention in RPLC using retention factors as retention parameters, this is the first study based on retention indices

Characterization of cardinal vine shoot waste as new resource of lignocellulosic biomass and valorization into value-added chemical using Plackett-Burman and Box Behnken

International audienceThe objective of this work was to valorize a waste from cardinal vine shoot into a hydrolysate rich in reducing sugars. Plackett-Burman design was considered to identify the significant factors, while a Box Behnken design was considered to optimize the extraction in the following experimental conditions: 100 degrees C, 750 rpm, trifluoracetic acid (CF3O2H) concentration (TFA) in the range (1-10%), for 20 to 180 min and considering the following solid-liquid (S/V) ratios (1:1, 3:1, 5:1). The optimal result was 2.53% in sugars equivalent to a yield of 50.64% per gram of dry matter. Shoot vine waste was characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), simultaneous thermal analysis (STA), and X-ray fluorescence (XRF). The chemical composition was 43.38% cellulose, 23.58% hemicellulose, 21.22% lignin, 2.53% ash, 5.82% crude protein, 11.7% moisture, and extractives (0.81% fat, 0.56% total sugars, 2.3% extractive (hexane-ethanol)). The promising potential of shoot vine waste to produce sugar and other added-value compounds was demonstrated