在线固相萃取-毛细管高效液相色谱联用测定奶酪中的生物胺

摘要

An on-line solid phase extraction coupled with capillary HPLC method was established for the simultaneous determination of fifteen kinds of biologic amines in cheese. The biogenic amines were concentrated on the solid phase extraction column, and transferred by the six-way valve to analytical column for separation and detection. Separation conditions on capillary HPLC, composition of on-line SPE mobile phase, pH of the sample solution and switching time of six-way switching valve were investigated to get better separation conditions of 15 biogenic amines. Optimum on-line SPE conditions including 5% of the acetonitrile-water as mobile phase for SPE column, pH=11 of the sample solution and 3 min of valve switching time were employed in the analytical method. The linear range of standard curve for fifteen biogenic amines was 0. 25-50. 0 mg/L;LOD were within the range of 0. 05-0. 25 mg/L. At spiked levels of 1, 20, 40 mg/kg, the recoveries of fifteen biogenic amines on four kinds of cheese ranged from 79 . 6% to 118 . 7% except methylamine, ethylamine, 3-methylbutanamine and 5-hydroxytryptamine; with RSDs from 0. 3% to 14. 9%except 3-methylbutanamine and 5-hydroxy-tryptamine. The method is accurate and reliable, and can be used to detect biogenic amines in cheese.%采用双二元泵毛细管液相色谱,通过六通阀实现了样品的在线净化与分离定量的自动切换,建立了同时测定奶酪中的15种生物胺的在线固相萃取-毛细管高效液相色谱联用方法。通过优化毛细管高效液相色谱的分离条件,考察在线固相萃取流动相的组成、上样溶液pH值以及六通阀的切换时间对生物胺回收率的影响,确定最佳分析条件为：5%乙腈-水作为固萃柱(Zorbax SB-C18)的流动相,上样溶液pH=11,上样3 min后切换六通阀。采用内标法定量,15种生物胺标准曲线的线性范围为0.25~50.0 mg/L,检出限( LOD)为0.05~0.25 mg/L,定量限(LOQ)为0.15~0.80 mg/L。除了甲胺、乙胺、3-甲基丁胺和5-羟基色胺外,其余生物胺的不同添加水平(1,20和40 mg/kg)下的加标回收率为79.6%~118.7%；除3-甲基丁胺和5-羟基色胺外,其余生物胺的RSD在0.3%~14.9%之间,可用于奶酪中多种生物胺的快速检测。