Use of cyclodextrin-based polymer for patulin analysis in apple juice

Penicillium expansum, one of the patulin producing fungi that causes decay on apple, is recognized as the main source of patulin contamination on apple and apple products. The widely used method for patulin analysis in apple juice is liquid-liquid extraction with ethyl acetate followed by HPLC-UV or LC-MS detection. Previous studies have shown cyclodextrin polymers to exhibit favorable adsorption properties for several classes of small organic molecules, including patulin in apple juice. In this study, an insoluble polymer composed of cyclodextrin crosslinked with 4 ,4 ʼ -methylenebis(phenyl isocyanate) was synthesized for use in the solid phase extraction of patulin from apple juice. Conditions investigated for this method were solvent for column conditioning, sample volume to load patulin on the column, solvent for washing, and solvent and volume for patulin elution and optimized recovery of patulin from the column. At the optimized conditions, the recovery and relative standard deviation (RSD) of patulin from apple juice spiked at 10, 20, 50, 80 and 100 ng mL were 78 and 20 %, 71 and 13 %, 78 and 17 %, 71 and 7.1 %, 67 and 2.9 %, respectively. Limit of quantitation (LOQ) of patulin in apple juice by this method was 10 ng mL.