Abstract:

The contents of toxoflavin (TF) and bongkrekic acid (BA) in foods are determined simultaneously by an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. The samples were ultrasonically extracted with 80% methanol aqueous solution. After centrifugation, the supernatants were purified by the QuEChERS EMR-Lipid. And after concentration and reconstitution, the samples were eluted by gradient with 0.1 % formic acid solution water and acetonitrile as mobile phases, which was detected by liquid-mass electrospray ion source in positive and negative modes, and quantified by external standard method. The results indicated that the TF and BA showed good linearity in the concentration range of 0.5-100 μg/L, and the correlation coefficient was larger than 0.995. Under different additive concentrations of various substrates, the recoveries were 86.8%-103.6%, and the average relative standard deviations (RSD) were less than 5%. The detection limit of the TF method was 0.1 μg/kg and the quantification limit was 0.2 μg/kg. Meanwhile, the detection limit of the BA method was 0.05 μg/kg, and the quantification limit was 0.1 μg/kg. The method has high sensitivity, good specificity, accuracy and reliability, and is suitable for the determination of TF and BA in foods.

Key words: toxoflavin, bongkrekic acid, ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) with triple quadrupole, QuEChER