Gas-chromatographic determination of type a trichothecene mycotoxins in extracts of Fusarium spp. isolated from Yugoslav corn hybrids

The study included 21 fungal cultures of Fusarium spp. isolated from Yugoslav corn kernels, as well as 3 control strains of F. sporotrichioides which are known producers of T-2 toxin and other type A trichothecenes. Liquid SYP medium, containing 5% sucrose 0.1% yeast extract and 0.1% peptone, was used for cultivation of fungi, for 5 days at 28 degrees C, on a rotatory shaker. Crude toxins were obtained by extraction with ethyl acetate. Purification was performed by application of SEP PAK C-18 column chromatography and preparative thin-layer chromatography. The standard trichothecene mixture and purified extracts of fungal cultures were derivatised of with trifluoroacetic acid anhydride with addition of NaHCO3. Trichothecene mycotoxin contents were determined by gaschromatography on an analytical capillary chromatographic column. The presence of T-2 toxin was detected in 52% of the tested filtrates, of fungi which mainly weak producers of this trichothecene (0.5 - 15.0 mg/l). Besides T-2 toxin, DAS, T-2 tetraol and HT-2 toxin were detected only in extracts of the control F. sporotrichioides strains. The methods for extraction, purification, derivatisation and determination of trichothecene mycotoxins by gas chromatography were modified allowing of very small amounts (0.5 ng for T-2 toxin, 0.2 ng for HT-2 toxin and DAS, and 0.1 ng for T-2 tetraol).