Abstract: A method was established for the determination of deoxynivalenol (vomitoxin) in grain and its products based on solid-phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample was firstly extracted by acetonitrile-water (84:16, v/v). The extract was then cleaned-up by an HLB solid phase extraction cartridge. The separation was carried out on a Phenomenex Kinetex C18 column (100 mm×4.6 mm, 2.6 μm) with a gradient elution using 0.3‰ ammonia solution-acetonitrile as mobile phases. The analysis of deoxynivalenol was performed under electrospray negative ionization mode. The limit of detection (LOD, S/N=3) and the limit of quantification (LOQ, S/N=10) were 20 μg/kg and 50 μg/kg, respectively. A good linearity (r ＞0.99) was achieved for the target compound over the range of 20~1000 μg/L. The recoveries at the three spiked levels (50, 100, 500 μg/kg) in the blank matrices such as flour, barley, soybean, rice, cornmeal, cassava and wheat, were varied from 75.6% to 111.0% with the relative standard deviations no more than 13.0%. The method is accurate, efficient, sensitive and practical. The cost of pretreatment is obviously reduced by replacing immunoaffinity columns and Mycosep columns with HLB columns which have the same purification effect.

Key words: deoxynivalenol, grain, grain products, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), solid-phase extraction (SPE)