V1/V2= (r1/r2) 2 where V1and V2 is the diameter for analytical and preparative column respectively, r1 and r2 is the flow rate for analytical and preparative HPLC respectively.

• 小中大色谱柱直径变大的化，流速也要跟着放大，保持线速度不变，分离效果变化很小。