求教这是什么流动相?如何过渡?就是那个acetonitrile to 100% dichloromethane不好理解。另一段原文是这样的“0 to 5 min, 80% acetonitrile in water;5 to 10 min, 100% acetonitrile; 10 to 15 min, acetonitrile to 100%dichloromethane; and 15 to 20 min dichloromethane, at a constantflow rate of 1 mL/min.”查看更多