固相萃取-液相色谱-串联质谱法测定莲蓉馅料中的二氧化硫脲

建立了固相萃取-液相色谱-串联质谱法测定莲蓉馅料中违法添加的二氧化硫脲的分析方法。采用0.05%(v/v)醋酸溶液从馅料中提取二氧化硫脲，经BOND ELUT PLEXA固相萃取柱(60 mg/3 mL)净化，采用Agilent亲水作用色谱柱(100 mm×2.1 mm，3.5 μm)分离，以0.01 mol/L醋酸铵(冰醋酸调pH至3.5)和乙腈为流动相，在多反应监测模式(MRM)下进行定性定量分析。最终，二氧化硫脲在10~1000 μg/L范围内线性关系良好，检出限(LOD)和定量限(LOQ)分别为8.0 μg/kg和30.0 μg/kg，方法回收率为75.3%~80.7%，相对标准偏差(n=6)不超过4.83%。此方法快速、准确、特异性强、灵敏度高、样品前处理方法简便易行，适用于莲蓉馅料中二氧化硫脲的确证与测定。

Determination of thiourea dioxide in lotus seed paste fillings by solid phase extraction-liquid chromatography-tandem mass spectrometry

A method of solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) was developed to determine thiourea dioxide which was illegally added into lotus seed paste fillings. An amount of 0.05% (v/v) acetic acid was used to extract thiourea dioxide from fillings, and the BOND ELUT PLEXA column (60 mg/3 mL) was used as the SPE column to clean-up the extraction. Then, an Agilent HILIC column (100 mm×2.1 mm, 3.5 μm) was applied to separate target compounds by using the mobile phases of 0.01 mol/L ammonium acetate (pH 3.5) and acetonitrile. Qualitative and quantitative analyses were operated by the multiple reaction monitoring (MRM) mode. The calibration curve showed a good linearity for the target compound in the detection range of 10-1000 μg/L. The limit of detection (LOD) and limit of quantitation (LOQ) of this method were 8.0 μg/kg and 30.0 μg/kg, respectively. The recoveries were in the ranges of 75.3%-80.7% with the RSDs of no more than 4.83%. This proposed method was rapid, highly specific and suitable for the confirmation and quantitative determination of thiourea dioxide in lotus seed paste fillings.