Preparation of monolithic polymer-magnetite nanoparticle composites into poly(ethylene-co-tetrafluoroethylene) tubes for uses in micro-bore HPLC separation and extraction of phosphorylated compounds

• Published in: Talanta (Oxford) 2021-03, Vol.224, p.121806-121806, Article 121806
• Main Authors: Torres-Cartas, Sagrario, Meseguer-Lloret, Susana, Gómez-Benito, Carmen, Catalá-Icardo, Mónica, Simó-Alfonso, Ernesto F., Herrero-Martínez, José Manuel
• Format: Article
• Language: English
• Subjects: Adenosine phosphates; EFTE tubing; HILIC; Hybrid monoliths; Magnetite nanoparticles; Monolithic column
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2020.121806

This paper describes the fabrication of a novel microbore monolithic column modified with magnetite nanoparticles (MNPs) prepared in a poly(ethylene-co-tetrafluoroethylene) (EFTE) tubing, and its application as stationary phase for the chromatographic separation of phosphorylated compounds. In order to obtain the composite column, a two-step procedure was performed. The formation of a glycidyl methacrylate-based monolith inside the activated ETFE tube was firstly carried out. Then, two incorporation approaches of MNPs in monoliths were investigated. The generic polymer was modified with 3-aminopropyltrimethoxysilane (APTMS) to be subsequently attached to MNP surfaces. Alternatively, APTMS-coated MNPs were firstly prepared and subsequently used for attachment onto the monolith surface through reaction of epoxy groups present in the generic monolith. This last strategy gave a reproducible layer of MNPs coated onto the polymer monolith as well as robust and permeable chromatographic columns. The retention behaviour of this MNP-based composite monolithic column was studied by using small phosphorylated compounds (adenosine phosphates). It was found that the retention of model analytes was ruled by partitioning and adsorption HILIC mechanisms. The columns also exhibited satisfactory performance in the separation of these target compounds, showing good chromatographic behaviour after two months of continued use. These composite monolithic columns were also successfully applied to the extraction of a tryptic digest of β-casein. [Display omitted] •MNP-modified monoliths were prepared in flexible tube for LC separation and extraction.•The hybrid monolithic columns showed hydrophilic separation features.•The hybrid monoliths were reproducible and stable under micro-bore LC conditions.•The composite columns exhibited satisfactory separation of phosphorylated compounds.•The hybrid monoliths can be satisfactorily used for phosphopeptide enrichment.