杂质吸附型净化结合超高效液相色谱-串联质谱法同时测定谷物和动物饲料中37种霉菌毒素

建立了谷物和动物饲料中霉菌毒素的高效、快速前处理方法，可同时提取和净化样品中37种理化性质差异较大的霉菌毒素，并采用超高效液相色谱-串联质谱（UPLC-MS/MS）进行定性和定量分析。样品粉碎处理后，经84%（体积分数，下同）乙腈水（含0.1%甲酸）溶液振荡提取20 min，MLJ-1杂质吸附型固相萃取柱净化。目标物在BEH RP18色谱柱上分离，以0.1 mmol/L乙酸铵溶液（含0.1%甲酸）和甲醇溶液（含0.1%甲酸）作为流动相进行梯度洗脱，质谱采用电喷雾正、负离子模式和多反应监测模式进行定性和定量分析。结果表明，本方法可在1 min内完成样品净化处理，15 min内完成37种目标化合物的分离分析。37种目标物在各自线性范围内线性关系良好，基质匹配标准曲线的相关系数均大于0.98。除伏马毒素外的所有目标化合物在4个添加水平下的回收率介于80%~120%之间，相对标准偏差（RSD）<20%（n=5），方法定量限为2~40 μg/kg，能够满足《饲料卫生标准》判定要求。该方法操作简单、快速、准确，适合谷物和动物饲料中多种霉菌毒素同步筛查和确证检测。

Simultaneous determination of 37 mycotoxins in grain and animal feed by impurity adsorption purification coupled with ultra-performance liquid chromatography-tandem mass spectrometry

A rapid method based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS) was developed for the simultaneous determination of 37 mycotoxins having various physicochemical properties in grain and animal feed samples. The 37 analytes were extracted from ground samples with acetonitrile-water-formic acid (84:15.9:0.1, v/v/v) by 20 min vibration, and purified using a commercial MLJ-1 pass-through solid-phase extraction (SPE) clean-up cartridge. The analytes were then separated on a reversed-phase BEH RP18 column by a gradient elution program with 0.1 mmol/L ammonium acetate (containing 0.1% (v/v) formic acid) aqueous solution and 0.1% (v/v) formic acid methanol solution as mobile phases. The separated analytes were detected by MS/MS in the multiple reaction monitoring (MRM) mode via ESI+/- ionization. The results showed that the purification was completed in 1 min and that the 37 analytes could be separated on the chromatographic column in 15 min. The 37 mycotoxins showed a linear relationship within their respective linear ranges, and the correlation coefficients of the matrix-matched calibration curves were greater than 0.98. The average recoveries at four spiked levels (limit of quantification (LOQ), LOQ×5, LOQ×10, LOQ×25) for all the targets except fumonisins ranged from 80% to 120%, with the relative standard deviations (RSDs) lower than 20% (n=6). The limits of quantification (LOQs) for all the analytes were between 2 and 40 μg/kg. The proposed method is simple, fast, and accurate, thus being suitable for detecting multiple mycotoxins in grain and animal feed samples.