采用pH梯度萃取法分离黄酮苷元类化学成分是利用它们（ ）的差异

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='29779' and id < 2418202 and id<>'2418202' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='29779' and id > 2418202 and id<>'2418202' order by id asc limit 5