采用同位素稀释法串联质谱的方法同时测定玉米中的多种霉菌毒素

Simultaneous determination of several mycotoxins in maize by ultra-high-pressure liquid chromatography-tandem mass spectrometry using ^(13)C_(15)-deoxynivalenol as internal standard

目的:采用超高压液相色谱-四极杆质谱联用技术UPLC-MS/MS,同时测定玉米中的赭曲霉素A等10种霉菌毒素。方法:样品用84/16的乙腈/水混合液匀浆提取3 min,经一种创新型的自制混合固相萃取柱纯化后经Acquity UH-PLC HSS T3柱(100 mm×2.1 mm,1.7μm particle size)分离,10 min内10种霉菌毒素完全分离。结果:采用13C-DON同位素内标法定量,MON 10~5000μg/kg,OTA 0.2~50μg/kg,OTB 0.2~50μg/kg,NIV 2~500μg/kg,ZON 5~500μg/kg,DON2~500μg/kg,15-ADON2~500μg/kg,3-ADON2~500μg/kg,ZAN 2~500μg/kg的浓度范围内呈良好的线性关系,r≥0.999。相对加样平均回收率为:75.8%~106.5%,RSD:1.7%~9.6%;LOQ在0.09~8.48μg/kg,满足欧盟限量标准。结论:该方法具有预处理简单、检测速度快、灵敏度高的优点,可适用于玉米样品中霉菌毒素的确认和准确定量检测,可满足各国对霉菌毒素的最低检出要求。运用建立的方法对各地的69份玉米产品进行含量测定,玉米样品中普遍存在霉菌毒素的污染。

Objective：A new approach for simple and rapid simultaneous determination of 10 kinds of mycotoxins contaminants in corn by ultra - performance liquid chromatography - tandem mass spectrometry is described. Methods： Homogenized samples were sequentially extracted by 84% （v/v） of acetonitrile aqueous solution, SPE clean -up with new selfmade column, centrifuge,evaporate, re- dissolve and filtration. After injection, the analytes were separated by Acquity UHPLC HSS T3 column （ 100 mm× 2. 1 mm, 1.7 p.m particle size）. All mycotoxins were separated by gradient elution with the retention time of 10 min. Results：Quantification of mycotoxins by ^13C -DON through internal standard method. High correlation coefficients （r t〉0. 999 ） of 10 mycotoxins were obtained within their respective linear ranges （ MON 10 - 5000 μg/kg, OTA 0. 2 N 50 μg/kg, OTB 0. 2 50 μg/kg, NIV 2 - 500 μg/kg, ZON 5 - 500 μg/kg, DON 2 - 500 μg/kg, 15 - ADON 2 - 500 μg/kg, 3 - ADON 2 500 μg/kg,ZAN 2 - 500 μ/kg）. The LOQ of selected analytes ranged from 0.09 to 8.48 μg/kg, which was lower than the criteria of EU on the determination of the minimum limiting level of mycotoxins in foods including baby foods and corn. Meanwhile, reasonable recoveries （75.8% - 106. 5% ） of them were also demonstrated in different spiked levels. Conclusion：This quantitative method has many advantages including simple pretreatment, rapid determination and high sensitivity, which could he applied to the determination and quantification of myeotoxins contaminants in maize. Meanwhile, the method successfully fulfils the minimum limiting level requests from various countries. Sixty - nine corn samples purchased from different districts have been sampled and analyzed by the validated method in the present study.