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目的建立面粉中尿素的高效液相色谱-荧光检测器法。方法样品用75%乙醇超声提取尿素,经过高速离心后,提取液在酸性条件下,与9-羟基吨反应产生具有荧光特性的吨基脲,采用Alltima C18HP高纯度硅胶基质的色谱柱进行液相分离后,在激发波长为213 nm、发射波长为308 nm的条件下,用荧光检测器进行定量检测。结果尿素浓度为0.05 mg/L~10.0 mg/L时,线性关系良好,回归方程为y=61 384x-44 839,相关系数(r)为0.999 9,方法的相对标准偏差(RSD)为4.4%~15.0%,回收率为75.4%~98.6%,检出限和定量限分别为0.98 mg/kg和2.94 mg/kg。结论该方法操作简便快速,结果准确稳定,可以适用于面粉中尿素含量的定量检测。
Objective To establish a method for the determination of urea in flour by high performance liquid chromatography with fluorescence detector. Methods The sample was extracted by ultrasonic with 75% ethanol. After high speed centrifugation, the extract reacted with 9-hydroxy ton to produce the t-butyl urea with the fluorescence characteristics under acidic conditions. The column was chromatographed on an Alltima C18HP high purity silica gel column After separation, the fluorescence detector was used for quantitative detection at an excitation wavelength of 213 nm and an emission wavelength of 308 nm. The results showed that the regression equation was y = 61 384x-44 839 and the correlation coefficient (r) was 0.999 9 when the urea concentration was 0.05 mg / L ~ 10.0 mg / L. The relative standard deviation (RSD) was 4.4% ~ 15.0%, and the recoveries ranged from 75.4% to 98.6%. The limits of detection and limit of quantification were 0.98 mg / kg and 2.94 mg / kg, respectively. Conclusion The method is simple, rapid, accurate and stable and can be applied to the quantitative determination of urea in flour.