液相色谱-串联质谱法同时测定调制乳制品中5种人工合成甜味剂

Determination of five synthetic sweeteners in modified milk by high performance liquid chromatography tandem mass spectrometry

建立了调制乳制品中安赛蜜、甜蜜素、糖精钠、阿斯巴甜和纽甜等5种人工合成甜味剂的液相色谱-串联质谱测定方法。对蛋白沉淀剂、色谱柱、流动相组成、超声时间以及质谱参数进行了优化。结果表明,样品经过0.2%乙酸水沉淀蛋白,MGⅢ-C18色谱柱(150 mm×2.0 mm,5μm)分离,甲醇和10 mmol/L乙酸铵水溶液流动相进行梯度洗脱,流速0.3 m L/min,采用液相色谱-串联质谱仪对目标化合物进行测定,基质外标法定量。在10~1020μg/kg范围内,线性相关系数(R2)>0.999,3个不同浓度添加水平下平均加标回收率90.0%~109.7%,精密度(RSD)为0.8%~7.6%(n=6)。调制乳制品中安赛蜜、甜蜜素、糖精钠、阿斯巴甜和纽甜的检出限分别为3.0,30,10,5和1.0μg/kg,定量限为10,100,40,20和3.3μg/kg。采用所建立的方法对市面上销售的8种调制乳中5种人工合成甜味剂进行筛查,达到预期效果。方法适用于调制乳制品中人工合成甜味剂的快速分析。

A rapid method was established and applied to the extraction of five synthetic sweeteners modified milk prior to the determination by liquid chromatography coupled to triple quadrupole mass spectrometry （HPLC-MS/MS）. Several parameters, including the protein precipitant, chromatographic column, the composition of the mobile phase, the ultrasonic time and the monitor ions, were optimized for improving the chromatographic performance and the sensitivity of determination. The results demonstrated that 0. 2% acetic acid-water as protein precipitant was used to extract the five sweeteners without any further clean-up step. The separation of the analytes was carried out on an MG Ⅲ-C18 column （150 mm × 2. 0 mm, 5 μm） using the mobile phases of methanol and 10 mmol/L ammonium acetate aqueous solution with gradient elution at a flow rate of 0. 3 mL/rain. Finally the samples were determined by HPLC-MS/MS. Matrix-matched calibration was used for the quantification. The proposed method showed good linearity with the correlation coefficients all above 0. 999. The recoveries of five synthetic sweeteners obtained by analyzing the three spiked levels were in the range of 90.0% - 109. 7% with the RSDs ranging from 0. 8% to 7.6%. The detection limits of five synthetic sweeteners were 3.0, 30, 10, 5.0 and 1.0 μg/kg, respectively. And the limit of quantitation were 10, 100, 40, 20 and 3.3 μg/kg, respectively. The developed method was successfully apphed for five synthetic sweeteners analysis in 8 samples. The present method was accurate and sensitive for the determination of a variety of synthetic sweeteners in modified milk.