Innovative preparation of ureido/dodecyl dual-functionalized silica as a versatile mixed-mode stationary phase for high-resolution chromatographic separations

Developing a versatile stationary phase to achieve the purpose of efficiently separating various target an-alytes is of great significance. In this work, ureido/dodecyl dual-functionalized silica (Sil-Ur-DD) was syn-thesized and employed as a new mixed-mode stationary phase for high-resolution chromatographic anal-ysis. It was observed that multiple interactions, including hydrophobic, hydrophilic, hydrogen bonding, electrostatic and pi-pi interactions, contributed to the retention. Nucleosides and nucleobases could be effectively determined in hydrophilic interaction chromatography mode, and the separation performance of the Sil-Ur-DD was found to be even superior to that of the commercial XAmide column. Environmental endocrine disruptors, including alkylphenols, bisphenols, steroid hormones and phthalates, were more fa-vorably separated in reversed-phase chromatography mode with highly aqueous mobile phases compared with the commercial C18-silica column. The experimental results indicated that the combined effect of ureido and long-chain alkyl groups obviously enhanced separation efficiency and selectivity. More signifi-cantly, the proposed method concerning the preparation of an efficient separation material with powerful separation ability is economical and environmentally friendly, which provides a proven and effective way for the recycling and utilization of the discarded chromatographic packing materials, thereby showing a good application prospect. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, a new mixed-mode stationary phase Sil-Ur-DD was synthesized and showed excellent separation performance in hydrophilic interaction chromatography and reversed-phase chromatography modes. The retention was contributed by multiple interactions. Furthermore, the proposed preparation method is cost-effective and environmentally friendly, providing a promising way for recycling and utilization of discarded chromatographic packing materials.