Pipette tip-based molecularly imprinted monolith for selective micro-solid-phase extraction of methomyl in environmental water

Abstract

A novel low molecular weight methomyl molecule-imprinted monolith (MIM) was prepared inside a polypropylene pipette tip by polymerization reaction. Then the pipette tip-based MIM micro-solid-phase extraction (PT-MIM-μ-SPE) method was developed for selective extraction of methomyl in aqueous solution. The extraction parameters, such as the sample flow rate, sample volume and elution solvent, were investigated. By combining with a high performance liquid chromatography-ultraviolet detector, the PT-MIM-μ-SPE method showed a good linear range of 0.6–1000.0 μg L⁻¹ with a low limit of detection of 0.2 μg L⁻¹. The method was also applied for the pretreatment of methomyl in various environmental water samples. The relative recoveries were in the range of 84.9 to 105.1% with relative standard deviations less than 9.0%. The results showed that methomyl could be selectively enriched and monitored from environmental water samples.