1H NMR-based analytical method: A valid and rapid tool for the epoxidation processes,
Tommaso Cogliano, Rosa Turco, Vincenzo Russo, Martino Di Serio, Riccardo Tesser,
Industrial Crops and Products, Volume 186, 2022, 115258,
The present work aims to propose a 1H NMR-based method for a rapid determination of conversion, yield, and selectivity in the epoxidation of organic substrates. Several experiments were carried out on different substrates and analyzed with both the proposed 1H NMR method and the volumetric traditional ones for a useful comparison. The results obtained with the traditional methods were deeply studied to find a mathematical correlation between the absolute analytical error and the double bond or oxirane ring concentration. The same was done for the conversion and yield derived from the analytical determinations. Finally, the results obtained with the proposed 1H NMR-based method on the epoxidation of methyl-oleate, as a model molecule, were compared with the results obtained by the traditional methods. A good agreement was obtained between the two classes of methods validating the proposed 1H NMR method.
Keywords: Quantitative 1H NMR-based analytical method; Epoxidation process; Epoxidized oils; Iodine value; Wijs method; Epoxy content