关键词: 薏米, 超高效液相色谱-串联质谱法, 交链孢霉毒素

Abstract: Objective To establish a solid phase extraction-isotope dilution liquid chromatography-tandem mass spectrometry for determination of four kinds alternaria toxins in coix seed,and to understand the contamination status of alternarian toxins in coix seed sold in Shenzhen. Methods 5 g of coix seed were extracted by acetonitrile-methanol-sodium dihydrogen phosphate solution after adding with mixed internal standards,cleaned up by solid phase extraction column,and determined by ultraperformance liquid chromatography tandem mass spectrometry. A total of 40 samples of commercially available coix seed were randomly collected from 10 administrative districts of Shenzhen,and the contents of 4 alternaria toxins were detected. Results The correlation coefficients of tenuazonic acid（TeA）,alternariol（AOH）,tentoxin（TEN） and alternariol methyl ether（AME） were found to be greater than 0.999,with detection limits ranging from 0.05-0.50 μg/kg. The recoveries were 70.88%-118.97%,and the relative standard deviations were 1.25%-12.43%. Coix seed on sale in Shenzhen were generally contaminated with various types of alternaria toxins,with an total detection rate of 95.0%（38/40）. TeA was the alternaria toxin with highest detection rate（82.5%,33/40） and highest average concentration（18.69 μg/kg）. Conclusion This method has good sensitivity and accuracy,high precision,and is suitable for detecting alternaria toxin in coix seed. The relevant regulatory authorities should propose targeted prevention and control measures to strengthen the quality management of coix seed in various aspects such as production,storage,transportation,and sales.

Key words: Coix seed, Ultra-high performance liquid chromatography-tandem mass spectrometry, Alternaria toxins