高效毛细管电泳浊度法检测牛奶及奶粉中的三聚氰胺

建立高效毛细管电泳(HPCE)浊度法检测牛奶和奶粉中三聚氰胺的方法。样品中加入三氯乙酸水溶液,加热样品至沸腾后自然冷却,使蛋白质充分凝聚、沉降,并提取三聚氰胺。色谱条件为:毛细管柱长度50cm、内径75μm,分离电压13kV,进样量12.3kPa×3s,分离温度25℃,检测波长236nm。加标回收率为83%～98%之间,定量限为1mg/kg。测量结果的相对标准偏差为1.8%～3.4%(n=5)。该法可用于大量牛奶和奶粉样品中三聚氰胺的快速检测。

DETERMINATION OF MELAMINE IN MILK AND MILK POWDER BY TURBIDIMETRIC METHOD OF HIGH PERFORMANCE CAPILLARY ELECTROPHORESIS

A method of high performance capillary electrophoresis （HPCE） was established for the separation of melamine in milk and milk powder. Trichloroacetic acid solution was used to precipitate proteins and to dissociate the melamine from the sample matrix. In order to dissociate the proteins clean and simply, the sample was heated to boil, then cooled naturally. Analysis was carried out on a fused -silicauncoated ,capillary column（ 50 cm × 75 μm）, completed at 25 kV of separation voltage and 236 nm detection wave length. The sample was injected by hydro - dynamic injection（ 12.3 kPa × 3s） at a temperature of 25℃. The average recoveries ranged from 83.2% to 97.5% in the spiked range of the determination of melamine in milk and milk powder. The limit of quantification （ LOQs） of milk and milk powder was 1.0 mg/kg, and the relative standard deviations were between 2.1% and 3.9% （ n = 5 ）. The method can be used for rapid detection of melamine for large number of milk and milk powder samples.