Polymer Monolith Use As On-line Solid-phase Microextraction Adsorbent For Pollutants

High-performance liquid chromatography (HPLC) method has been widely applied to analyze organic pollutants. In these analytical methods, sample pretreatment is an important process to enrichment the analyte. Solid-phase microextraction (SPME) is a simple and fast extraction technique, which has gained widespread acceptance for analyte matrix separation and preconcentration. Compared to the conventional solvent extraction techniques, it is a solvent-free technique and can be combined with HPLC.Use of a monolith column as the sorbent in SPME has advantages including ease of preparation, low-pressure drop, and rapid mass transport. The pore size and structure of the column is controlled by changing the monomers and their relative proportions. To prepare a monolith column, various polymerization methods have been demonstrated, including the click reaction. The Huisgen1,3-dipolar cycloaddition reaction is an valuable click reaction, which has been implemented widely since its discovery. In this reaction, Cu(I) is used as catalyst, with alkynyl and azido as the active groups, to obtain1,2,3-triazole compounds. This type of click reaction is usually used for surface functionalization of a monolith column, in both the organic-inorganic hybrid monolith column and the polymer monolith column.A polymer monolith column was prepared using click chemistry for on-line solid phase microextraction, using2,2’,7,7’-tetraethynyl-9,9’-spirobifluorene(TES) and1,4-bis-(6-azidoalkoxy)-benzene(BAB) as monomers, and Cu(PPh3)3Br as the catalyst. The polymer monolith was used as on-line solid-phase microextraction adsorbent coupled to HPLC for determination of amines, phenols, polycyclic aromatic hydrocarbons (PAHs) and estrogens. The π-π stacking interaction and the effect of small size played dominant roles in the adsorption.