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This paper describes a method for the analysis of DON and its derivatives in wheat and barley using combination gas chromatography/mass spectrometry (GC/MS). The method has been designed for the analysis of large batch (100 g) samples and single kernels. The sensitivity of the method is 50 ppb (ng/g), and the precision in terms of percent standard deviation lies between 0.0 and 11.1. The percent recovery for 1, 5, and 10 µg/g (ppm) recovered from wheat is 97.2, 88.4 and 87.9% respectively. A comparison of methods was made between two laboratories using GC/EC and our method. There was no significant difference between the results of the two methods. The method is also applicable to 15-acetyldeoxynivalenol (15-ADON) as well as nivalenol (NIV). Standard curves constructed for DON, 15-ADON, and NIV show a linear relationship between 0.025 ng (limit of sensitivity) and 8 ng.

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Wheat ears were inoculated with conidia of Fusarium spp. at different growth stages between ear emergence and harvest and moist conditions were maintained for up to 7 days subsequently by mist irrigation. Of the fungi tested (Fusarium culmorum, F. avenaceum, F. tricinctum, F. sporotrichioides and Microdochium nivale), only F. culmorum produced ear blight symptoms and grain samples were found subsequently to contain deoxynivalenol. Most ear infection and deoxynivalenol formation occurred following inoculation at about mid-anthesis. Small amounts of deoxynivalenol were formed and some F. culmorum was isolated even in the absence of ear blight symptoms. An overnight wet period was sufficient to initiate infection and deoxynivalenol formation but both were increased by extending the wet period up to at least 3 days. Recovery of Fusarium spp. from harvested grain was usually possible whether or not symptoms developed. F. culmorum usually persisted and often increased to moderately high levels after storage for 7 wk in a range of moisture conditions.