Chromatographic separation simulation of metal-chelating peptides from surface plasmon resonance binding parameters.

Some metal-chelating peptides have antioxidant properties, with potential nutrition, health, and cosmetics applications. This study aimed to simulate their separation on immobilized metal ion affinity chromatography from their affinity constant for immobilized metal ion determined in surface plasmon resonance, both technics are based on peptide-metal ion interactions. In our approach, first, the affinity constant of synthetic peptides was determined by surface plasmon resonance and used as input data to numerically simulate the chromatographic separation with a transport-dispersive model based on Langmuir adsorption isotherm. Then, chromatographic separation was applied on the same peptides to determine their retention time and compare this experimental tR with the simulated tR obtained from simulation from surface plasmon resonance data. For the investigated peptides, the relative values of tR were comparable. Hence, our study demonstrated the pertinence of such numerical simulation correlating immobilized metal ion affinity chromatography and surface plasmon resonance.

Iron-impregnated zeolite catalyst for efficient removal of micropollutants at very low concentration from Meurthe river.

In this paper, for the first time, faujasite Y zeolite impregnated with iron (III) was employed as a catalyst to remove a real cocktail of micropollutants inside real water samples from the Meurthe river by the means of the heterogeneous photo-Fenton process. The catalyst was prepared by the wet impregnation method using iron (III) nitrate nonahydrate as iron precursor. First, an optimization of the process parameters was conducted using phenol as model macro-pollutant. The hydrogen peroxide concentration, the light wavelength (UV and visible) and intensity, the iron loading immobilized, as well as the pH of the solution were investigated. Complete photo-Fenton degradation of the contaminant was achieved using faujasite containing 20 wt.% of iron, under UV light, and in the presence of 0.007 mol/L of H2O2 at pH 5.5. In a second step, the optimized process was used with real water samples from the Meurthe river. Twenty-one micropollutants (endocrine disruptors, pharmaceuticals, personal care products, and perfluorinated compounds) including 17 pharmaceutical compounds were specifically targeted, detected, and quantified. All the initial concentrations remained in the range of nanogram per liter (0.8-88 ng/L). The majority of the micropollutants had a large affinity for the surface of the iron-impregnated faujasite. Our results emphasized the very good efficiency of the photo-Fenton process with a cocktail of a minimum of 21 micropollutants. Except for sulfamethoxazole and PFOA, the concentrations of all the other microcontaminants (bisphenol A, carbamazepine, carbamazepine-10,11-epoxide, clarithromycin, diclofenac, estrone, ibuprofen, ketoprofen, lidocaine, naproxen, PFOS, triclosan, etc.) became lower than the limit of quantification of the LC-MS/MS after 30 min or 6 h of photo-Fenton treatment depending on their initial concentrations. The photo-Fenton degradation of PFOA can be neglected. The photo-Fenton degradation of sulfamethoxazole obeys first-order kinetics in the presence of the cocktail of the other micropollutants.