Combination of magnetic solid-phase extraction and HPLC-UV for simultaneous determination of four phthalate esters in plastic bottled juice

A magnetic o-hydroxyazobenzene (M-HAzo) porous organic polymer was facilely prepared by a green azo coupling reaction in aqueous solution. The prepared M-HAzo was applied as a new adsorbent for the first time to pre-concentrate phthalate esters (PAEs) from plastic bottled juice, followed by their determination with high performance liquid chromatography-ultraviolet detection. The effects of various parameters, i.e., the mass ratio of the Fe3O4@SiO2 to HAzo, extraction time, ionic strength, pH of the sample, desorption conditions were optimized. Under the optimized conditions, the M-HAzo based method exhibited good performance in terms of linear range (0.3–50.0 μg L−1), detection limit (0.08–0.50 μg L−1), accuracy (recovery of 78.0–115.0%) and repeatability (relative standard deviation of 2.9–7.8%). This work provides a sensitive method for analysis of PAEs at trace levels in drinks, which is featured with high sensitivity, simple operation and environmentally-friendly merit and will have a promising potential in analysis of other organic pollutants.