Abstract: A determination method of deoxynivalenol(DON)in wheats and corns by capillary gas chromatography was studied. Samples were extracted with acetronile-water(84:16,V/V).The wheats liquid extracts were then purified by Florisil columns, while the corn liquid extracts were purified by a two-step procedure with both Florisil and active carbon columns.The final extract was then derivatized with N-heptafluorobutyrylimidazole(HFBI)and quantitated by GC with electron capture detector(GC- ECD).Recoveries of DON were spiked at 0.5～1.5 mg/kg ranged from 82.2% to 98.5% for wheat and from 86.0% to 103.4% for corn,with relative standard deviations of 6.2%～7.6% and 6.4%～8.0%,respectively.The limit of detection(S/N=3:1) of this method is 0.01 mg/kg for DON.The linearity of the detector response is proper in 0.075～15 mg/kg.21 wheat and 20 corn samples were analysed by GC-ECD,whereas 10 wheat samples are found contaminated with DON in 0.153～4.618 mg/kg.17 corn samples are found contaminated with DON in 0.116～3.004 mg/kg.

Key words: capillary gas chromatography, derivatized, deoxynivalenol, N-heptafluorobutylimmidazole, cereals