Wei Jie, Guo Zhimou, Shen Aijin, Zhang Feifang, Liang Xinmiao
School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China.
Se Pu. 2011 Jul;29(7):687-90.
A simple, rapid method for the determination of melamine in milk and milk powder was developed using QuEChERS approach coupled with weak cation exchange chromatography (WCX). The samples were extracted and cleaned-up by medicinal alcohol and lipid adsorbent (LAS) simultaneously, then centrifuged and filtered for high performance liquid chromatographic (HPLC) analysis. The separation was performed on a WCX column (150 mm x 4.6 mm, 5 microm) with 2 mmol/L KH2 PO4 (pH 3.8) as mobile phase. The flow rate was 1.5 mL/min and the detection wavelength was 208 nm. The injection volume was 20 microL and the column temperature was 30 degrees C. Under the optimized conditions, good linearity was obtained in the range of 0.02-20 mg/L with a correlation coefficient (r2) of 0.999 9. For samples spiked with melamine standard in the range of 1-50 mg/kg, the average recoveries of standard in the milk and milk powder were 98.9%-105.2% and 86.4%-102.9%, respectively. The relative standard deviations were 0.9%-3.4% and 1.5%-6.7%, respectively. The limits of detection (LOD, S/N > or = 3) were 0.05 mg/kg (milk) and 0.1 mg/kg (milk powder). The present method is green due to not use of the toxic organic solvents.
建立了一种简单、快速测定牛奶和奶粉中三聚氰胺的方法，该方法采用QuEChERS方法结合弱阳离子交换色谱（WCX）。样品用医用酒精和脂质吸附剂（LAS）同时进行提取和净化，然后离心并过滤用于高效液相色谱（HPLC）分析。在WCX柱（150 mm×4.6 mm，5μm）上进行分离，以2 mmol/L KH2PO4（pH 3.8）为流动相。流速为1.5 mL/min，检测波长为208 nm。进样体积为20μL，柱温为30℃。在优化条件下，在0.02 - 20 mg/L范围内获得了良好的线性关系，相关系数（r2）为0.999 9。对于添加三聚氰胺标准品浓度在1 - 50 mg/kg范围内的样品，牛奶和奶粉中标准品的平均回收率分别为98.9% - 105.2%和86.4% - 102.9%。相对标准偏差分别为0.9% - 3.4%和1.5% - 6.7%。检测限（LOD，S/N≥3）为0.05 mg/kg（牛奶）和0.1 mg/kg（奶粉）。该方法由于不使用有毒有机溶剂，因此是绿色环保的。
