Construction of a portable sample preparation device with a magnetic poly(methacrylic acid-co-ethylene dimethacrylate) monolith as the extraction medium and its application in the enrichment of UV filters in water samples

A portable sample preparation device with a magnetic polymer monolith as the extraction medium was constructed. The monolith was synthesized by polymerizing methacrylic acid and ethylene dimethacrylate around a cylindrical magnet. In this way, the monolith with a magnetic core could be readily attached to the extraction device by magnetism. The constructed device was evaluated for the enrichment of UV filters in water samples, followed by high-performance liquid chromatographic analysis. The extraction efficiency for the targets was satisfactory with no matrix interference. Good linearities were obtained for the UV filters with the correlation coefficients >0.9986. The limits of detection and quantification for the UV filters were 0.3-0.8 and 1.0-2.4 ng/mL, respectively. The recoveries of the UV filters from the spiked water samples at the concentration of 100 ng/mL were 95.3-101.7%, with relative standard deviations <10%. Accordingly, the proposed portable device was demonstrated to be suitable for on-site simultaneous sampling, purification, and preconcentration within a single step.