Determination of 26 Mycotoxins in Feedstuffs by Multifunctional Clean-up Column and Liquid Chromatography-Tandem Mass Spectrometry

A rapid high-throughput method for the determination of 26 mycotoxins involving multifunctional clean-up column coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination in feedstuffs. The feedstuff samples were extracted by ultrasonic treatment for 1 h, and the mixture of acetonitrile/water/formic acid (84:15.9:0.1, V/V) was used as the extraction solvent. After purified by a commercial Mycospin 400 multifunctional clean-up column, 1 mL of the supernatant layer was evaporated and redissolved by 0.25 mL of water/methanol/formic acid (95:4.9:0.1, V/V) in a vial for injection into the LC-MS/MS system. Then chromatographic analyses were carried out on a reversed phase C18 column using a gradient elution with 0.1% formic acid aqueous solution and 0.1% formic acid methanol solution. After that, the mass spectrometer was operated in a multiple reaction monitoring (MRM) mode selected one precursor ion and two product ions for each target compound. Validation studies were carried out in maize and soybean meal as representative matrixes. Since most target compounds had different levels of matrix effects, matrix-matched calibration was adopted for quantification. Mean recoveries from spiked samples at three levels ranged from 61.9% to 119.5% with relative standard deviations of 0.8%-18.6%. Limits of quantification ranged from 0.5 mu g kg(-1) to 50 mu g kg(-1).