A highly sensitive method for detection of bisphenol A in water samples based on functionalised Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>@nylon66

<p>A simple and sensitive method was developed for preconcentration and determination of bisphenol A (BPA) in environmental samples by high performance liquid chromatography (HPLC). The hydrophilic silicon-dioxide- and nylon66-functionalised magnetic material (Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>@nylon66) was used as a sorbent for magnetic solid-phase extraction (MSPE). With the anhydrous microemulsion reaction, the Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>@nylon66 had shown great characteristics such as good magnetic responsivity, water dispersibility and stability. Based on the materials, various extraction parameters including pH, extraction time, elution time, the number of sorbents, sample volume and elution times were optimised. The whole extraction procedure could be accomplished within 20 min and the materials could be used more than 10 times after regeneration. Under the optimised conditions, different types of water samples (Tap water, river water, sea water and underground water) were successfully analysed to verify the applicability of the proposed method. The recoveries of different samples ranged from 88.54% to 104.46%. An enrichment factor of 250 was achieved with 0.05 μg/L detection limit. Thus, the developed MSPE is a potential technique that can be used for water samples preconcentration or combined with other analytical methods for determination of BPA.</p>