Efficient entrapment of inorganic Se species in water and beer samples with functional groups-rich monolith-based adsorbent

An efficient multiple fibers solid-phase microextraction method based on porous monolith was established for Se(IV) and Se(VI) analysis. Poly(4-vinylphenylboronic acid/styrene-co-ethylene dimethacrylate/divinylbenzene) monolith was fabricated and employed as the extraction phase for efficient entrapment of Se(IV) complexed with o-phenylenediamine, followed by elution with a methanol/formic acid (99/1.0, v/v) mixture and quantification by high-performance liquid chromatography with diode array detector. The Se(VI) species was measured by the difference between total inorganic Se and Se(IV) after pre-reduction. Different characterization techniques were employed to inspect the structure and morphology of prepared adsorbent. A series of key extraction factors were optimized so as to achieve the expected extraction performance. Under the optimized separation and capture parameters, the linear range and limit of detection for Se(IV) in water sample were 0.050–200 and 0.013 μg/L, respectively. For beer sample, the corresponding values were 0.010–300 and 0.032 μg/L. The developed microextraction approach was successfully utilized to detect trace Se(IV) and Se(VI) in environmental water and beer samples with satisfactory fortified recovery and repeatability. Results well reveal the attractive merits of the established method in the analysis of Se species, including simple preparation of adsorbent, convenient extraction procedure, good sensitivity, high cost-effectiveness, and eco-friendliness.