Abstract: Objective To understand the content level of alternaria toxins in some grains sold in Shenzhen, and provide basic datas for long-term and effective risk monitoring. Methods Some grain samples sold in Shenzhen in 2023 were purified by solid phaseextraction column,determined by liquid chromatography-tandem mass spectrometry,and quantitatively detected by internal standard method.The content levels of alternaria toxins in different samples were analyzed statistically. Results In flour and flour products and corn-based products in Shenzhen in 2023, the detection ranges of tenuazonic acid（TeA） were 1.18-45.50 and 0.25-40.10 μg/kg respectively, with detection rates of 100.00% and 93.33% respectively. The detection ranges of tentoxin（TEN） were 0.05-5.88 and 0.05-1.30 μg/kg respectively, with detection rates of 90.00% and 50.00% respectively. The detection ranges of alternariol monomethylether（AME） were 0.03-1.33 and 0.03-6.75 μg/kg respectively,with detection rates of 88.33% and 93.33% respectively. The detection range of alternariol（AOH） in corn products was 0.50-2.11 μg/kg,with a detection rate of 26.67%. Conclusion The detection rate of alternariatoxins in some grains sold in Shenzhen in 2023 was high. However, the content levels were at lower levels compared to published literatures.

Key words: Alternaria toxins, Flour and flour products, Corn-based products, Content, Grains