例：纯度要求 Pethidine Hydrochloride CH3 盐酸哌替啶 CH:HCI CH3 OCH3 HCI CH3 HCI 无效异构体虹 无效异构体Ⅱ O CH3 HCl N CH3 O O N CH3 OCH3 HCl O CH3 HCl O N C2H5 例：纯度要求 Pethidine Hydrochloride 盐酸哌替啶 无效异构体I 无效异构体 II