Ultrasonic extraction with ultra-performance liquid chromatography/tandem mass spectrometry for the determination of ochratoxin A in processed cereal products.

A rapid, simple, and reliable method using ultra-performance LC/MS/MS (UPLC/MS/MS) was developed for determination of ochratoxin A (OTA) in processed cereal products. OTA was ultrasonically extracted from the sample with acetonitrile-water (80 + 20, v/v), and the extract was then injected into the UPLC/MS/MS system after filtration. The calibration curves had good linearity with coefficients of determination greater than 0.999. Recoveries of OTA were in the range of 90-104%. LOD and LOQ of OTA in samples were 0.6 and 2.0 ng/g, respectively, and no significant matrix effect was found. This method was applied to determine OTA in 25 oat-based cereal samples. OTA was detected in five samples (20%) in the range of 2.4 to 7.3 ng/g.