Solid-Phase Extraction Method for Patulin in Apple Juice and Unfiltered Apple Juice

Patulin, a mold metabolite, is commonly found in rotting apples. Some countries regulate patulin at levels ranging from 30 to 50 μg/L. Most analytical methods for patulin in apple juice include liquid—liquid partitions. A solid¯phase extraction method has been developed for apple juice and unfiltered apple juice in the United States. A portion of the test sample (5 mL) was passed through a macroporous copolymer cartridge and was washed with 1 mL 1 % sodium bicarbonate and then with 1 mL 1 % acetic acid. Patulin was eluted with 3 mL 2% acetonitrile in anhydrous ethyl ether and was determined by reversed-phase liquid chromatography with UV detection at 276 nm. Recoveries ranged from 93 to104% in test samples spiked at 20-100 μg/L.

Thin Layer Chromatographic Determination of Deoxynivalenol in Processed Grain Products

The thin layer chromatographic (TLC) method of Trucksess et al. (J. Assoc. Off. Anal. Chem. (1984) 67, 40-43) was modified for the determination of deoxynivalenol (DON) in high-sugar breakfast cereals, corn syrup, and beer. Celite was added to the substrate before extraction with acetonitrile-water (84 + 16). After filtration through an aluminacharcoal-Celite (0.5 + 0.7 + 0.3) column, the filtrate was evaporated to dryness and redissolved in water, which was passed through an octylsilyl reverse phase column. DON was eluted with anhydrous ethyl ether. The residue remaining after the eluate was evaporated to dryness was dissolved in CHCl3-acetonitrile (4 + 1) and chromatographed on AlCVimpregnated silica gel TLC plates. The blue fluorescent DON spot was quantitated fluorodensitometrically after the TLC plate was heated at 120°C for 7 min. Recoveries of DON added to breakfast cereals at 100, 200, and 400 ng/g levels and to syrup and beer at 50, 100, and 200 ng/g levels averaged 86%. The limit of determination in these products was about 50 ng/g.