盐酸苯达莫司汀的电喷雾串联质谱分析

目的:应用电喷雾串联质谱(ESI-MSn)技术对盐酸苯达莫司汀进行质谱裂解分析,通过主要特征碎片离子研究其裂解规律。方法:样品溶液进样后,采用ESI-MS1～4碰撞裂解方式,解析盐酸苯达莫司汀的特征碎片离子。结果:盐酸苯达莫司汀在正离子模式下,采用ESI-MS1获得了分子离子峰[M+H]+m/z 358;采用ESI-MS2获得了离子碎片m/z340;采用ESI-MS3获得m/z304、m/z276等离子碎片;采用ESI-MS4得到的主要离子碎片分别为m/z240、m/z268、m/z276等。负离子模式下采用ESI-MS1获得了[M-H]-m/z356,而采用ESI-MS2～4碰撞裂解,基本无响应。结论:盐酸苯达莫司汀在正离子模式下,主要通过脱去羧基中的H2O、CO碎片和5位N上的HCl、CH3Cl以及CH2=CHCl碎片的方式进行裂解。负离子模式下,只有一级电离产生的分子离子峰[M-H]-m/z356有一定响应。说明盐酸苯达莫司汀在负离子模式下比较稳定,而在正离子模式下容易裂解产生一系列碎片。本研究为盐酸苯达莫司汀的结构修饰及其代谢产物结构判断提供参考依据。

Electrospray ionization tandem mass spectrometry analysis of bendamustine hydrochloride

Objective： To analyze the fragments of bendamustine hydrochloride by electrospray ionization tandem mass spectrometry（ESI-MSn） and deduce the MS/MSn fragment pathway.Methods： The samples were directly injected into the instrument and the fragments of the samples were yielded by ESI-MS1-4.Results： Molecular ions fragment ~ of bendamustine hydrochloride at m/z 358 was oberserved in the positive ion mode of ESI-MS1,fragment ion m/z 340 was detected by ESI-MS2,the main fragment ions m/z 304,276 were found in ESI-MS3 and fragment ions at m/z 240,268 and 276 were detected by ESI-MS4,respectively.On the other hand,only molecular ion fragment _at m/z 356 was observed at the negative ion mode for bendamustine hydrochloride in MS/MSn fragment pathway.Conclusion： In the positive ion mode,the characteristic fragment ions of bendamustine hydrochloride are gained mainly by elimination of H2O,CO from the carboxy and HCl,CH3Cl,CH2=CHCl from the nitrogen（N） of 5-carbon.However,only fragment ion of _at m/z 356 is gained in the negative ion mode.Evidences suggest that bendamustine hydrochloride is more stable in the negative ion mode,and is easy to crack into a series of fragment ions in the positive mode.These results may provide evidence of the chemical modification of bendamustine hydrochloride and structural identification of its metabolic components.