液相色谱法检测馅料和米面食品中二氧化硫脲

本文建立了超声萃取结合液相色谱测定馅料和米面食品中二氧化硫脲的方法。用光谱扫描的方式，确定了二氧化硫脲的检测波长为274 nm；用HILIC-Z的柱子和0.2%（V/V）乙酸水溶液、乙腈为流动相，梯度洗脱可实现对目标物的较好分离；优化确定样品中二氧化硫脲的提取条件：0.1%（V/V）的乙酸水溶液为提取液，采用冰水浴的条件超声30 min。二氧化硫脲在0~250 mg/L的浓度范围内，线性关系良好，相关系数R2=0.9999，检出限0.2 mg/L，定量限0.5 mg/L，空白样品在三个水平（0.5 mg/kg、1 mg/kg、5 mg/kg）的加标回收实验中，回收率95.67%~100.37%，相对标准偏差（RSD）0.53%~4.45%，回收率和RSD均符合方法学要求。样品检测中，紫薯馅料和绿豆馅料中都检出了二氧化硫脲，含量分别是8.30 mg/kg、236.36 mg/kg。本方法具有操作简便，重现性好和准确度高的优点，可用于检测分析食品中二氧化硫脲。

Determination of Thiourea Dioxide in Fillings and Rice Flour Food by Liquid Chromatography

The method for the determination of thiourea dioxide in fillings and rice flour food by ultrasonic extraction and liquid chromatography was established in this work. The detection wave length of thiourea dioxide was 274 nm by means of spectral scanning. The target was separated well by gradient elution with HILIC-Z column and 0.2% (V/V) acetic acid aqueous solution and acetonitrile as the mobile phase. The extraction condition of thiourea dioxide in samples was 0.1% (V/V) acetic acid aqueous solution as extraction solution and 30 min ultrasound in ice water bath. The linear relationship of thiourea dioxide in the concentration range of 0~250 mg/L was good and the correlation coefficient was R2=0.9999. The detection limit and quantitative limit were 0.2 mg/L and 0.5 mg/L, respectively. The average recovery was 95.67%~100.37% for the spiked blank sample at three levels (0.5 mg/kg, 1 mg/kg and 5 mg/kg). The relative standard deviation (RSD) was 0.53%~4.45%. The recovery and RSD could meet the requirements of the methodology. Thiourea dioxide was detected in purple potato filling and mungbean filling and the content was 8.30 mg/kg and 236.36 mg/kg, respectively. The method had the advantages of simple operation, good reproducibility and high accuracy and could be used for the determination of thiourea dioxide in food.