Development and validation of a simple and fast method for simultaneous determination of aflatoxin B1 and sterigmatocystin in grains.

In this study, a simple, fast, sensitive and reliable method was developed for the simultaneous determination of aflatoxin B1 (AFB1) and sterigmatocystin (STC) in rice, wheat, maize, oat, rye and barley grains based on a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method and liquid chromatography-tandem mass spectrometry (LC-MS/MS). AFB1 and STC were extracted using 95% acetonitrile in water and cleaned up using N-Propylethane-1,2-diamine (PSA). The method was validated according to the SANCO/12571/2013 regulation of the European Union (EU). Recoveries at three spiked levels of 0.5, 2.5 and 5.0μg/kg ranged from 77.7% to 119.7% and the relative standard deviations (RSDs) were between 1.3% and 12.8%. Limits of detection (LOD) were 0.03 and 0.02μg/kg for AFB1 and STC, respectively. The limit of quantification (LOQ) was 0.5μg/kg for both AFB1 and STC. The proposed method was successfully applied to determine AFB1 and STC levels in ten non-processed rice samples from Guangdong province in China.