Determination of beauvercin and enniatins in rice flour and wheat flour by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

Abstract

To develop a method for the determination of beauvercin(BEA), enniatin A(ENNA), enniatin A1(ENNA1), enniatin B(ENNB) and enniatin B1(ENNB1) in rice flour and wheat flour by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). Samples were extracted by acetonitrile-water, purified by Oasis Prime HLB solid-phase extraction column. The sample solution was separated by waters BEH C_(18) column(2.1 mm×100 mm, 1.8 μm). The detection was performed in the electrospray positive ionization(ESI+) under multiple reaction monitoring(MRM) mode. The internal standard method and the matrix-matched calibrations were used for quantification. The linear relationships of BEA and 4 kinds of enniatins(ENNs) were good in the range of 0.1-50.0 ng/mL(r>0.999). The average recoveries of BEA and ENNs in rice flour and wheat flour were 96.4%-105.4% and 99.1%-109.2%, with the relative standard deviations(RSD) of 1.01%-7.42% and 1.09%-9.69%(n=6). The detection limits(LOD) of BEA and ENNs were 0.03 μg/kg. The quantitative limits(LOQ) of BEA and ENNs were 0.1μg/kg. The matrix induced suppression or enhancement effect were 72.7%-99.3% and 60.8%-100.4%, respectively. The levels of emerging BEA and ENNs in wheat flour were higher than rice flour. The detection rate of enniatin B was highest in wheat flour and rice flour, the contents were 0.03-9.57 μg/kg and 0.03-0.56 μg/kg, the positive percentage were 98.5% and 36.4%. The method is quick, easy, accurate and sensitive, which is suitable for the determination of BEA and 4 kinds of ENNs in rice flour and wheat flour.