高效液相色谱法测定奶粉中双氰胺的拟水平正交试验

Pseudo- level orthogonal test for determination of dicyandiamide in milk powder by high performance liquid chromatography

目的通过拟水平正交试验优选出较满意的测定奶粉中双氰胺的高效液相色谱法条件。方法用乙腈提取奶粉水溶液中的双氰胺、经净化,用高效液相色谱法就流动相中缓冲液浓度、pH值、乙腈与缓冲液的配比以及流速进行拟水平正交试验。结果乙腈和乙酸铵(20 mmol/L,pH=7)的配比为85︰15,流速为0.8 ml/min是较为满意的实验条件。结论拟水平正交试验试验量相对少,适用于液相色谱法测定奶粉中双氰胺实验条件筛选。

Objective To develop an analytical method for determination of dicyandiamide in milk powder by high performance liquid chromatography（HPLC） using pseudo -level orthogonal test. Methods The dicyandiamide was extracted with acetonitrile from milk powder solution, then purified and determined by HPLC using four factors （ concentration of ammonium acetate, pH values of buffer, ratio of acetonitrile and buffer, flow rate of mobile phase） for pseudo - level orthogonal test. Results The ratio of acetonitrile and ammonium acetate （20 mmol / L, pH = 7） as 85 ： 15, and the flow rate of 0.8 ml/min were the satisfactory experimental condition. Conclusion The pseudo - level orthogonal test required less samples than routine test. It is suitable for determination of dicyandiamide in milk powder by HPLC.