The optimized analytical methodology described herein is based on an ion exchange column and an H 3 PO 4 solution (pH 2.24) as the mobile phase, with a flow rate of 0.4 mL min-1 and refractive index detection (RID). On applying the methodology, it was possible to identify 7 products obtained from the oxidation of glycerol with an analysis time of 27 min. The developed method was validated through the evaluation of a series of analytical parameters. The results obtained were evaluated considering the peak area and peak height. The analytical curves showed a correlation coefficient of ≥ 0.986. The coefficient of variation values obtained were ≤ 3.60% for instrumental precision, ≤ 19.36% for intermediate precision in LOQ (1.25 µg mL-1) and ≤ 17.93% for repeatability in LOQ (1.25 µg mL-1) and different days. The limit of quantification established for all compounds was 1.25 μg mL-1 obtained through the parameters of the analytical curve. The accuracy of the method showed recovery values of 85.6 to 112.3% for real fortified sample at 3 concentration levels. Two different samples of glycerol oxidation products were applied to the validated methodology; one obtained from AuNP/SiO 2 as catalyst (conversion of 62.42%), and other using AuNP/MWCNT (conversion of 89.5%).

Esterification of oleic acid (OA) and glycerol (GLY) is studied in the absence and in the presence of the organotin(IV) catalysts (CAT) dibutyltin dichloride (Bu2SnCl2), butyltin trichloride (BuSnCl3), dibutyltin dilaurate (Bu2SnLau2), butyl stannoic acid (BuSnO(OH)), and di‐n‐butyl‐oxo‐stannane (Bu2SnO). The reactivity order observed at 180 °C using a OA/GLY/CAT molar ratio of 1/1/0.01 was BuSnCl3 > Bu2SnLau2 > Bu2SnCl2 > Bu2SnO > BuSnO(OH), and a kap of −0.6237 h−1 is obtained for BuSnCl3. The estimated activation energy for the conversion reaction of OA at the above molar ratio using BuSnCl3 is 60.9 kJ mol−1, whereas it is 71.3 kJ mol−1 for the reaction performed without the catalyst. Moreover, the most active catalytic systems are those that act as typical and pure Lewis acids, and the least active systems are those that follow the ligand exchange mechanism, suggesting that GLY and AO are involved in the ligand exchange process and may form less reactive catalytic species. Practical Applications: In order to expand the glycerol utilization, the aim of the present work is to systematically investigate the behavior of organotin(IV) compounds bearing different substituents on the metal center (oxo, carboxyl, chloro, and hydroxy groups) in the esterification of OA and GLY without a solvent for obtaining MAGs, DAGs and TAGs. Best results of esterification of AO + GLY are attained at 180 °C using BuSnCl3 as a catalyst, and the kap = −0.6237 h−1 for OA conversion is obtained.

No abstract