高效液相色谱/质谱联用技术快速鉴定左氧氟羧酸原料药中微量未知杂质  

Rapid characterization of an unknown impurity in bulk drug levofloxacin carboxylic acid by high performance liquid chromatography/mass spectrometry

作　　者：彭蕊[1] 吴健美[2] 孙翠荣[3] 

机构地区：[1]兰州大学化学化工学院,兰州730000 [2]公安部禁毒情报技术中心,北京100193 [3]浙江大学化学系,杭州310027

出　　处：《兰州大学学报（自然科学版）》2013年第2期283-287,共5页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(81230080)

摘　　要：左氧氟羧酸是合成喹诺酮类抗菌药物左氧氟沙星的主要原料,在其合成过程中产生了一个微量未知杂质.运用高效液相色谱/质谱联用结合串联质谱技术对其进行分析发现,该杂质的分子量及分子式与左氧氟羧酸的相同,其碰撞诱导解离二级和三级质谱产生的碎片离子及其丰度也与左氧氟羧酸的相似.通过对该杂质的多级质谱裂解机理进行分析总结,结合高分辨质谱数据,推测该杂质为9,10-二氟-11-羟基-2-甲基-2,3-二氢-1,6-苯并[e][1,4]噁唑啉-5,7-二酮,与左氧氟羧酸分子结构的差异体现为异丙基环合位置不同.其结构得到核磁共振波谱技术的进一步确证.An unknown impurity in the bulk drug levofloxacin carboxylic acid was detected by high performance liquid chromatography coupled with mass spectrometry （HPLC-MS）. The impurity has the same formula and molecular weight with levofioxacin carboxylic acid. The mass multi-stage spectrometric spectra （MSn） of impurity exhibit characteristic fragmentation routes similar to those of levofloxacin carboxylic acid. The unknown product was then proposed as 9, 10-difluoro-ll-hydroxy-2-methyl-2, 3-dihydro-1, 6-（metheno）benzo[e][1, 4]oxazonine＊5, 7-dione on the basis of the proposed mass spectrometric mechanism and exact mass evidences. The proposed structures were further confirmed by NMR experiments.

关 键 词：左氧氟羧酸 未知杂质 多级质谱技术 核磁共振技术 

分 类 号：O657[理学—分析化学]