Detection of masked mycotoxins derived from type A trichothecenes in corn by high-resolution LC-Orbitrap mass spectrometer.

Masked mycotoxins (mycotoxin glucosides) derived from type A trichothecenes were detected in commercially available corn powder reference material. These new glucosides were identified as neosolaniol-glucoside (NESGlc) and diacetoxyscirpenol-glucoside (DASGlc) on the basis of accurate mass measurements of characteristic ions and fragmentation patterns using high-resolution liquid chromatography-Orbitrap mass spectrometric (LC-Orbitrap MS) analysis. Although the absolute structure was not clarified, 3-OH glucosylation appeared to be the most probable when considering the structures of neosolaniol and diacetoxyscirpenol and the fragmentation profiles of these masked mycotoxins. Concomitant detection of deoxynivalenol-3-glucoside, the most well-known masked mycotoxin derived from the type B trichothecene, deoxynivalenol, in the identical material further supports this probability.

Detection of a new Fusarium masked mycotoxin in wheat grain by high-resolution LC-Orbitrap™ MS.

A new Fusarium mycotoxin glucoside, fusarenon X-glucoside (FUXGlc), is reported for the first time in wheat grain that was artificially infected with Fusarium fungi. This new glucoside was identified using LC Orbitrap high-resolution mass spectrometry (LC-Orbitrap MS) analysis on the basis of accurate mass measurement of characteristic ions and MS/MS fragmentation patterns. Although the absolute structure of FUXGlc was not clarified by LC-MS, 3-OH glucosylation seems to be the most probable structure based on the fragment profile and considering that deoxynivalenol-3-glucoside (DON3Glc) was reported as the predominant glucosylated derivative of the structurally similar mycotoxin, deoxynivalenol (DON). Another mycotoxin glucoside, nivalenol-glucoside (NIVGlc) was also found in the same grain sample. According to the semi-quantification by LC-Orbitrap MS, more than 15% of FUX and NIV were estimated to be converted into respective glucosides. The existence of these masked mycotoxins should be taken into account in risk assessment, since they could be transformed back to the corresponding mycotoxins under certain conditions; for example, through various food processing operations or in the digestive tract of mammals after ingestion.