Browsing by Subject "Mycotoxins"

Mycotoxins are toxic secondary metabolites of fungi which have adverse health effects on humans and animals. Among the mycotoxins, aflatoxin B1 (AFB1) and fumonisin B1 (FMB1) are one of the biggest threats to food safety and often co-occur in cereals with possible synergistic toxic effects. Due to the climate change, it is predicted that mycotoxin-producing fungi will spread in their geographical distribution and consequently threaten food quality and availability to a whole new level. The aim of this study was to optimize and validate an in-house quantification method for AFB1 and FMB1 in cereals using wheat bran as a representative matrix for matrix-matched calibration. The method was based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) using the multiple reaction monitoring (MRM) technique for quantification. AFB1 and FMB1 were extracted with 70% acetonitrile containing 1% formic acid using horizontal shaking for 30 min. The purification was done using hexane and the QuEChERS method. The chromatographical separation of mycotoxins was performed in Acquity UPLC BEH C18 column and the detection was carried out with a quadrupole time-of-flight (QTOF) mass spectrometer. AFB1 showed a severe ion suppression (matrix effect: 20%) and FMB1 a slight ion enhancement (matrix effect: 108%) in the wheat bran matrix. These alterations of the ionization were successfully compensated by 13C-labeled internal standards and matrix-matched calibration. Quantification was performed by considering the peak area ratio and concentration ratio of the target analyte (AFB1 and FMB1) and its internal standard. Both AFB1 and FMB1 showed good linearity (R2 ≥ 0.995), high recoveries (89-92%) in spiking experiments and the low relative standard deviation within and between different days (3.3-6.9%). The method quantification limit was 1.0 ng/g for both mycotoxins. Uncertainty of the analysis for FMB1 in reference material was 644 ± 86 ng/g (k = 2, providing an approximate 95% confidence level when normal distribution was assumed). The validated LC-QTOF-MS method using wheat bran as a representative matrix fulfilled the performance criteria of Commission Regulation (EC) No 401/2006 and showed good performance for oat bran and maize flour.