亲水性色谱柱高效液相色谱法测定米面及制品中的二氧化硫脲

Determination of thiourea dioxide in rice,flour and their products by hydrophilic chromatographic column high performance liquid chromatography

目的建立测定米面及制品中二氧化硫脲的亲水性色谱柱高效液相色谱(high performance liquid chromatography,HPLC)检测斱法。方法样品中的二氧化硫脲经0.5%乙酸提取液在冰浴中超声提取10 min,10000 r/min离心3 min后取上清液过0.22μm水相微孔滤膜待测。对10.00 mg/L的二氧化硫脲标准溶液色谱峰迚行光谱扫描,确定二氧化硫脲的最大吸收波长为272 nm。采用Waters XBridge BEH HILIC(150 mm×4.6 mm,3.5μm)色谱柱迚行分离,以纯水:乙腈=20:80(V:V)为流动相,外标法定量。结果二氧化硫脲在0~50 mg/L范围内,二氧化硫脲的浓度与色谱峰面积的大小成正比例线性关系。线性斱程为Y=1.3701X-0.4482,相关系数为0.9999。斱法检出限为2.00 mg/kg。在斱法检出限、2倍斱法检出限、10倍斱法检出限3个水平迚行加标回收实验与精密度实验,回收率分别为93.0%、95.0%、96.4%,相对标准偏差分别为5.2%、4.1%、2.5%。结论该斱法准确度与精密度符合GB/T 27404-2008《实验室质量控制觃范食品理化检测》的相应技术要求,斱法准确稳定可靠,满足米面及制品中二氧化硫脲的测定。

Objective To establish a method for the determination of sulfur dioxide in rice,flour and their products by high performance liquid chromatography（HPLC） with urea hydrophilic chromatography column.Methods The thiourea dioxide in the sample was ultrasonically extracted in an ice bath for 10 m in with 0.5% acetic acid,centrifuged at 10000 r/min for 3 min,and the supernatant was passed through a 0.22 μm aqueous microporous membrane for testing.A spectral scan of the 10.00 mg/L thiourea standard solution peak was performed to determine the maximum absorption wavelength of thiourea dioxide at 272 nm.Waters XBridge BEH HILIC（150 mm× 4.6 mm,3.5 μm） column was used for the separation.Pure water：acetonitrile=20：80（V：V） was used as the mobile phase and external standard method was used for quantification.Results The results showed that in the range of 0-50 mg/L,the concentration of thiourea dioxide was proportional to the size of the chromatographic peak area.The linear equation was Y=1.3701 X-0.4482.The correlation coefficient was 0.9999.The limit of detection was 2.00 mg/kg.The standard recovery experiment and precision experiment were carried out at 3 levels with 1,2 and 10 times of limit of detection,and the recovery rates were 93.0%,95.0% and 96.4%,respectively.The relative standard deviations were 5.2%,4.1% and 2.5%,respectively.Conclusion The accuracy and precision of this method conforms to the technical requirements of GB/T 27404-2008 Laboratory quality control standard for food physical and chemical testing.The method is accurate and reliable,which can satisfy the determination of thiourea dioxide in rice,flour and their products.