The development of a rapid assay for patulin

Abstract

Patulin is a mycotoxin found in many commodities including apples, grapes, and corn. It is produced primarily by Penicillium expansum and P. patulum although many other species of Penicillium, Aspergillus, and Byssochlamys are also known to produce this mycotoxin. Patulin is most commonly found in apple products where its presence may constitute a human health risk. At present, the best method for control of patulin is the detection and diversion of contaminated apple juice and products. A field-practical method for the chemiselective immobilization and detection of patulin has been developed in our lab. In this new method, the derivative of patulin is selectively adsorbed in a small glass n-minicolumn at the interface of a layer of packed neutral sand and narrow band silica gel. Patulin, at the level of 50 ppb or greater, can be easily detected as the presence of a bright yellow fluorescent band with this assay. Briefly, the sample is extracted with ethyl acetate and passed through a silica gel cartridge (or silica gel concentrating column). Patulin is then partitioned by polarity and eluted from the cartridge with acetonitrile. The eluant (containing patulin) is derived with 9-anthroylnitrile. The derivative is added to the minicolumn detector and viewed under longwave (UV) light. The limit of detection for this assay was determined to be 50 ppb. This assay was found to be accurate and rapid. Also, the patulin detector were shown to be chemically stable, requiring no special treatment for storage up to 20 weeks. In summary, the assay was shown to be rapid, practical, easy to perform, and stable, thus facilitating its use in the prescreening of apple products.