多项选择题 High performance liquid chromatography-pre-column derivatization method Aflatoxin B1, B2, G1, G2 solid phase purification column purification to remove interference substances such as ___ to obtain a purification solution.

判断题 A distinct purpose is important in defining an organization. 正确 错误

单项选择题 下列物质碱性由大到小的顺序为：A.苯胺  　　 B.二甲胺 　　  C.氨 　　　　  D.甲胺 A、ABCD B、BACD C、BCDA D、BDCA