Study of the natural occurrence of T-2 and HT-2 toxins and their glucosyl derivatives from field barley to malt by high-resolution Orbitrap mass spectrometry

Abstract

This paper reports a new method for the determination of T-2 and HT-2 toxins and their glucosylated derivatives in cereals, and some survey data aimed at obtaining more comprehensive information on the co-occurrence of T-2 and HT-2 toxins and their glucosylated derivatives in naturally contaminated cereal samples. For these purposes, barley samples originating from a Northern Italian area were analysed by LC-HRMS for the presence of T-2, HT-2 and relevant glucosyl derivatives. Quantitative analysis of T-2 and HT-2 glucosides was performed for the first time using a recently made available standard of T-2 glucoside. The glucosyl derivative of HT-2 was detected at levels up to 163 µg kg^–1 in 17 of the 18 analysed unprocessed barley grains, whereas the monoglucosyl derivative of T-2 toxin was detected in only a few samples and at low µg kg^–1 levels. The ratio between glucosylated toxins (sum of T-2 and HT-2 glucosides) and native toxins (sum of T-2 and HT-2) ranged from 2% to 283%. Moreover, taking advantage of the possibility of retrospective analysis of full-scan HRMS chromatograms, samples were also screened for the presence of other type-A trichothecenes, namely neosolaniol, diacetoxyscirpenol and their monoglucosyl derivatives, which were detected at trace levels. A subset of nine different samples was subjected to micro-maltation in order to carry out a preliminary investigation on the fate of T-2, HT-2 and relevant glucosides along the malting process. Mycotoxin reduction from cleaned barley to malt was observed at rates ranging from 4% to 87%.

Keywords:

• T-2 toxin
• HT-2 toxin
• neosolaniol
• diacetoxyscirpenol
• trichothecene glucosides
• modified mycotoxins
• high-resolution mass spectrometry
• barley
• malt

Acknowledgements

The authors thank Giuseppe Panzarini for technical assistance in LC-HRMS analysis.

Additional information

Funding

This work was carried out with financial support from the Project ‘MICOPRINCEM’ funded by the Italian Ministry of Agricultural, Food and Forestry Policies (MiPAAF).