Molecularly imprinted polymer for extraction of patulin in apple juice samples

A new molecularly imprinted polymer (MIP) was prepared in a two-step process. First, SiO2-gamma-MPTS was obtained by mixing gamma-methacryloxypropyltrimethoxysilane (gamma-MPTS) and tetraethoxysilane (TEOS). Second, SiO2-gamma-MPTS was polymerized in the presence of patulin (PAT) as a template, maleic acid (MA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross linker, 2,2-azobis- (2-methylpropionitrile) (AIBN) as a precursor and acetonitrile as a porogen solvent. The prepared sorbent was successfully applied to selective solid phase extraction (SPE) of PAT in containing apple juices and the MIP@SPE method was validated. The optimum conditions for PAT extraction using the novel MIP@SPE were: 50 mg mass of adsorbent, sodium bicarbonate with (1%) acetic acid as washing solvent and 5 mL acetonitrile as eluting solvent. The developed MIP@SPE method had high selectivity and good affinity toward PAT and the recoveries of the target analyte were in the range of 82-98% with a precision of 3.03%-3.83% (RSD). In addition, a good linearity (r(2) > 0.99) within the range 0.1-10 mg L-1 and a low LOD (8.6 mu g L-1) and LOQ (28.6 mu g L-1) were obtained. The test of reusability showed good results for at least 6 cycles. (C) 2016 Elsevier Ltd. All rights reserved.