11楼: Originally posted by YBMCL at 2012-11-22 11:11:12
已知杂质超过质量标准限度的话，最好修改工艺，把杂质降低到质量标准范围以下。未知杂质要是大于0.1%的话，需要结构确证，但最好还是优化工艺，降低杂质到小于0.1%。

12楼: Originally posted by caijing0343725 at 2012-11-22 11:22:53
谢谢！如果已知杂质没有超过质量标准限度，我们也有杂质对照品，那是不是不不要做质谱来进行结构确证啦？...

3楼: Originally posted by catwithdog at 2012-11-22 03:35:27
For your reference:
For impurity ID, you can use MS, NMR, HPLC, IR, UV. Most of time you need at least 2 methods. If you have that impurity ( 杂质 ) reference standard, you can run HPLC to compare t ...