稳定性同位素稀释-超高效液相色谱串联质谱法测定腐竹中的乌洛托品

采用超高效液相色谱-串联质谱法（UPLC-MS/MS）和稳定性同位素稀释技术,建立了测定腐竹中乌洛托品的分析方法。以乙腈为提取溶剂,向腐竹样品中加入乌洛托品的稳定性同位素,经固相萃取柱净化,采用HILIC色谱柱分离,目标物在UPLC-MS/MS的多反应监测（MRM）模式下,内标法定量。该方法在1⁴0μg/L范围内有良好的线性关系,相关系数为0.9996,方法定量限为2μg/kg。在添加水平为2、10、30μg/kg时,平均回收率为97.8%¹01.5%,相对标准偏差（RSD）为1.9%⁴.8%。本方法灵敏度高,准确度和重复性好,可为作为检测腐竹中违法添加乌洛托品的方法。 

Determination of urotropine in bean curd sticks by stable isotopic dilution- liquid chromatography with tandem mass spectrometry

A stable isotope dilution mass spectrometry technology for determination of urotropine in bean curd sticks by liquid chromatography with tandem mass spectrometry was developed.Isotopic urotropine was added to bean curd sticks as internal standard,and extracted with acetonitrile.Solid phase extraction( SPE) was applied to purify the sample.The separation was performed on a HILIC column. The analyte was determined by multiple reaction monitoring( MRM) mode with UPLC- MS / MS,and quantified by the internal standard method.The method showed good linear relationship in the range of 1⁴0 μg / L for urotropine,the correlation coefficient square was 0.9996.The limit of quantitation( LOQ) for sample was 2 μg / kg.The average recoveries were 97.8% ¹01.5% at spiked levels of2,10,30 μg / kg.The relative standard deviation( RSD,n = 6) was 1.9% ⁴.8%.This method is sensitive,accurate and reproducible.It is suitable for monitoring illegally added urotropine in bean curd sticks.