Nano-Liquid Chromatography with a New Monolithic Column for the Analysis of Coenzyme Q10 in Pistachio Samples

Abstract

Coenzyme Q10 (CoQ10) is a vital substance found throughout body. It helps convert food into energy and is eaten small amounts in foods. CoQ10 has gained great interest in recent years as a potential candidate for the treatment of various diseases. The content of CoQ10 in food samples is a crucial quality index for foods. Therefore, the development of sensitive separation and quantification method for determining the amount of CoQ10 in various samples, especially in foods, is an important issue, especially for food nutrition. In this study, a new, miniaturized monolithic column was developed and applied for the determination of CoQ10 in pistachio samples by nano-liquid chromatography (nano-LC). The monolithic column with a 50 µm i.d. was prepared by in situ polymerization using laurylmethacrylate (LMA) as the main monomer and ethylene dimethacrylate (EDMA) as the crosslinker. Methanol (MeOH) and polyethyleneglycol (PEG) were used as porogenic solvents. The final monolithic column was characterized by using scanning electron microscopy (SEM) and chromatographic analyses. The monolithic column with a 50 µm i.d. was applied to the analysis of CoQ10 in pistachio samples in nano-LC. This analytical method was validated by means of sensitivity, linearity, precision, recovery, and repeatability. The LOD and LOQ values were 0.05 and 0.48 µg/kg, respectively. The developed method using the monolithic column was optimized to achieve very sensitive analyses of CoQ10 content in the food samples. The applicability of the method was successfully demonstrated by the analysis of CoQ10 in pistachio samples.

Optimization of the Preparation of Hydrophilic Poly(DHPMA-co-MBA) Monolithic Capillary Columns: A New Support for Affinity Chromatography

“…Finally, the efficiency of the monolith (8 cm in length) was evaluated at about 9400 ± 1300 plates (n = 3 columns) at the optimal linear flow velocity uopt of 0.09 cm s −1 (i.e., 117,600 plates/m at 206 nL min −1 ), which was achieved by using thiourea as a retained solute (k = 0.4 at 80/20 (v/v) acetonitrile/water mobile phase composition (Figure 2)). These column kinetic performances with a high efficiency for an optimum flow rate close to 0.1 cm s −1 for organic monoliths are very interesting and are representative of the overall structural homogeneity of the monolith [28,29]. To confirm the highly hydrophilic character of the monolith, its ability to separate compounds in the HILIC mode was evaluated, as illustrated Figure 3, with the separation of five nucleosides.…”