Determination of aflatoxins in food using liquid chromatography coupled with electrospray ionization quadrupole time of flight mass spectrometry (LC-ESI-QTOF-MS/MS)

A rapid, reliable and confirmatory method has been developed to determine the levels of aflatoxins B1, B2, G1, and G2 in barley, wheat, soybean, corn, peanut and peanut butter. The method is based on a single extraction step followed by liquid chromatography coupled with electrospray ionization quadrupole time of flight mass spectrometry (LC-ESI-QTOF-MS/MS). The extraction, dilution, chromatographic and MS conditions were optimized in order to increase the sample throughput and sensitivity. The quantification of the analytes was measured by performing low-energy collision induced tandem mass spectrometry (CID-MS/MS) using the product ion scan mode. The calibration curves were linear over the range from 0.195 to 50.000 μg/kg for aflatoxin B1, G1 and from 0.029 to 15.000 μg/kg for aflatoxin B2, G2. The correlation coefficients (r2) were higher than 0.998. The overall recoveries for aflatoxins were in the range of 57.1–108.7% at spike levels of 0.6–15.0 μg/kg with relative standard deviations lower than 16%. The limit of quantification (LOQ) for aflatoxins is less than 0.8 μg/kg.