Determination of bisphenol A in tea samples by solid phase extraction and liquid chromatography coupled to mass spectrometry

Abstract

A simple, fast, sensitive and selective method for the extraction of Bisphenol A (BPA) from tea samples has been developed. Due to the low concentration of the analyte, sample preparation using Solid Phase Extraction (SPE) with a Molecularly Imprinted Polymer (MIP) as a sorbent was used to preconcentrate BPA from samples. The MIP was synthesized by the precipitation polymerization using BPA as a template, methacrylic acid (MAA) as a monomer, ethylene glycol dimethacrylate (EDMA) as a crosslinking agent, 2,2′-azobisisobutyronitrile (AIBN) as an initiator, and acetonitrile as a solvent. The optimized SPE process was applied loading 100 mL of the sample through the MIP sorbent at a flow rate of 1.0 mL min−1. The retained BPA was then eluted with 4 mL of methanol. Finally, the extract was analysed by High-Performance Liquid Chromatography-Electrospray Ionization Coupled to a Mass Spectrometry (HPLC-ESI-MS) working in negative mode. The method showed good recovery and precision (% RSD of 7.3). The limits of detection and quantification were 0.072 μg L−1 and 0.24 μg L−1, respectively. The optimized method was applied to BPA determination in several commercial tea samples.