Removal of patulin from aqueous solutions by propylthiol functionalized SBA-15.
Propylthiol functionalized SBA-15 silica was investigated to detoxify aqueous solutions contaminated with the regulated mycotoxin patulin. Micelle templated silicas with a specific pore size were synthetically modified to possess propylthiol groups, a functional group known to form Michael reaction products with the conjugated double bond system of patulin. BET surface area analysis indicated the propylthiol functionalized SBA-15 possesses channels with the pore size of 5.4 nm and a surface area of 345 m(2)g(-1). Elemental analysis indicates the silicon/sulfur ratio to be 10:1, inferring one propylthiol substituent for every ten silica residues. The propylthiol modified SBA-15 was effective at significantly reducing high levels of patulin from aqueous solutions (pH 7.0) in batch sorption assays at room temperature. The material was less effective at lower pH; however heating low pH solutions and apple juice to 60 °C in the presence of propylthiol functionalized SBA-15 significantly reduced the levels of patulin in contaminated samples. Composite molecular models developed by semi-empirical PM3 and empirical force field methods support patulin permeation through the mesoporous channels of propylthiol functionalized SBA-15. Density functional study at the B3LYP/6-31G(d,p) level predicts the proposed patulin adducts formed by reaction with the thiol residues exhibit less electrophilic properties than patulin. It is demonstrated the use of propylthiol functionalized SBA-15 is a viable approach to reduce patulin levels in aqueous solutions, including contaminated apple juice.
Bacterial Foodborne Pathogens and Mycology Research Unit, United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815N University St, Peoria, IL 61604, USA. michael.appell@ars.usda.gov
Michael
M
Appell
Michael A
MA
Jackson
Mary Ann
MA
Dombrink-Kurtzman
D002851:Chromatography, High Pressure Liquid; D008958:Models, Molecular; D010365:Patulin / Q000302:isolation & purification* / Q000633:toxicity; D012822:Silicon Dioxide / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000633:toxicity
C509969:SBA-15; D013438:Sulfhydryl Compounds; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; D010365:Patulin