小中大液相色谱柱串联？4个连续的柱子，增加保留时间？
看文献测定毒素用的液质，但是写了一句four serial octadesyl silica columns，4个连续的柱子，这是什么作用？增加保留时间？太夸张了吧？小弟初做色谱，不太懂，请高手指点，一下是原文节选：
trichothecenes were quantified by liquid chromatography-mass spectrometry (Model ZQ Quattro Micro, Waters, Milford, MA) with an octadesyl silica
column and the mobile phase of acetonitrile/10 mM ammonia
acetate water/methanol (5:90:5) for DON or NIV and with four
serial octadesyl silica columns and acetonitrile/10 mM ammonia
acetate water (25:75) for 3ADON or 15ADON.
