高效液相色谱法测定奶粉中双氰胺质量浓度

Determination of dicyandiamide in infant milk powder by high performance liquid chromatography

通过对实验的提取条件和色谱分离条件的优化,建立了高效液相色谱法测定奶粉中双氰胺质量浓度的方法.用质量分数为1％三氯乙酸从奶粉中提取双氰胺,以氨基柱分离,以乙腈-水作为流动相,流速为1.0 mL/min,检测波长为218 nm,采用二极管阵列检测器进行检测.结果表明,双氰胺在质量浓度为0.008～4.0 mg/L范围内线性良好,相关系数为0.9998.双氰胺的检出限为最低仪器检出限为1 μg/L,方法的定量下限为0.08mg/kg,加标回收率为84.7％～103.2％,相对标准偏差小于3.48％.方法的前处理方便,仪器要求简单,结果准确可靠,安全环保,适合于奶粉中双氰胺的定量检测.

A method has been developed for the determination of dicyandiamide in milk powder by high-performance liquid chromatography （HPLC）.The conditions of extraction and chromatographic conditions were optimized in the present study.Milk powder samples were extracted using 1% trichloroacetic acid, and then separated on a NH2-column using mixture of acetonitrile-water as mobile phase at a flow rate of 1.0 mL/min. The detection of dicyandiamide was performed by diode array detector （DAD） with a wavelength of 218 nm. The result shows that, a good linear relationship was obtained in the range between 0.008 mg/L and 4.0 mg/L, with a correlation coefficient of 0.9998. The detection limit of dicyandiamide was 1 ug/L, the quantitation limit of method was 0.08 mg/kg. The spiked recoveries were between 84.7% and 103.2%, and the RSD was less than 3.48%.The pretreatment of the method was convenient, the requirement of instrument is ordinary, and the result was accurate and reliable, and the experiment process is much safer and greener. It is suitable for the quantitative analysis of dicyandiamide in milk powder.