超高效液相色谱法测定乳及液态乳制品中三聚氰胺的含量

Quantitative Determination of Melamine in Milk and Liquid Dairy Products by Ultra-High Performance Liquid Chromatography

建立了超高效液相色谱法(UPLC)测定乳及液态乳制品中三聚氰胺含量的检测方法。样品用乙腈(含2.5%甲酸)提取,采用Luna Omega C18(2.1 mm×100 mm,1.6 μm)色谱柱,以0.5 mmol/L乙酸铵水溶液(含0.1%甲酸)/乙腈(95+5)为流动相,流速为0.15 mL/min,检测波长为240 nm,柱温38 ℃,进样量3 μL。结果表明:在该色谱条件下,三聚氰胺在0.5~100 μg/mL范围内呈良好的线性关系,相关系数r≥0.9986,方法检出限为0.23 mg/kg,定量限为1 mg/kg,在3个不同浓度添加水平下,平均加标回收率为75.6%~94.2%,方法的相对标准偏差RSD为0.5%~3.3%,仪器的精密度RSD(n=6)为0.6%。所建立的方法灵敏、准确、简便、重现性好,在测定乳及乳制品中三聚氰胺的含量方面具有较好的应用前景。

To develop ultra-high performance liquid chromatography (UPLC) method for the quantitative determination of melamine in milk and liquid dairy products,the samples were extracted with acetonitrile (2.5% formic acid).Luna Omega C18 (2.1 mm×100 mm,1.6 μm)column was used.The mobile phase consisted of 0.5 mmol/L ammonium acetate aqueous solution (containing 0.1% formic acid)-acetonitrile (95+5) at the flow rate of 0.15 mL/min.The detection wavelength was at 240 nm and the column temperature was 38 ℃.The injection volume was 3 μL.Results showed that the linear range of melamine was from 0.5 to 100 μg/mL (r=0.9986).The limit of detection was 0.23 mg/kg,and the limit of quantitative was 1 mg/kg,the average recoveries were 75.6%~94.2%,RSD of the method was 0.5%~3.3%,and RSD (n=6) of the instrument was 0.6%.The method is simple,accurate,sensitive and reproducible.It could have a nice application foreground in determination of melamine in milk and dairy products.