Determination of Ochratoxin A in Edible and Medicinal Foods by HPLC-Fluorescence Technology

Objective: To develop a method to determine ochratoxin A(OTA) in edible and medicinal foods using immunoaffinity column purification and high performance liquid chromatography(HPLC).Methods: Powdered samples were extracted with methanol-water(8:2,V/V) sequentially by vortex mixing,ultrasonic treatment and shaking.The resulting extract was diluted with phosphate buffer solution,filtrated and cleaned up on immunoaffinity column(IAC) containing antibodies specific to OTA.The pooled eluate was separated on a C18 column(4.6 mm × 150 mm,3μm) and detected by fluorescence detector(FLD).Results: The limit of detection(LOD,RSN = 3) was 1.0μg/kg for OTA.An excellent linear relationship between peak area and OTA concentration was observed in the OTA concentration range of 0.5-100 ng/mL with correlation coefficient of 0.9995.The average recovery rates for OTA in prince ginseng root,lotus seed,coix seed,Radix Ophiopgonis,dried longan pulp and oriental water plantain rhizome spiked with OTA standard at a level of 1-8μg/kg were varied from 81.8%-107% with a relative standard deviation(RSD) of 1.66%-15.0%(n = 3).Conclusion: This method has the advantages of satisfactory results and high accuracy and precision and can meet the requirements of the Europe Union for the determination of OTA in food and feed,thus providing a suitable method for determining OTA edible and medicinal foods rich in starch or sugar.