各位高手请指教: 我用液相色谱按照欧洲药典测定维库溴铵杂质,药典上面主峰是在5分钟左右出峰,最后一个杂质A的相对保留时间是1.3左右。但是我测的时候主峰在3分钟左右出峰,杂质A确在几乎19分钟出峰的,我调节乙腈与水的比例时几乎不影响主峰位置,但杂质却跑到30分钟了。柱子应该没什么影响吧 Column: — size: l = 0.25 m, Ø = 4.6 mm; — stationary phase: spherical octadecylsilyl silica gel for chromatography R (5 μm); — temperature: 40 °C. Mobile phase: mix 50 volumes of a 18.0 g/l solution of tetramethylammonium hydroxide R adjusted to pH 6.5 with phosphoric acid R, 250 volumes of methanol R and 700 volumes of acetonitrile R. Flow rate: 2.0ml/min. (retention time = about 5 min) : impurity C = about 0.8 ; impurity D = about 0.9 ; impurity E = about 1.2 ; impurity A = about 1.3. 我的柱子是sepx technologies,Inc的,Amethyst C18-H,4.6*250.;partical size:5um; pore size:120A 仪器岛津LC-10AT 请指教,多谢了