伊维菌素在电喷雾质谱中的行为及其机理的研究  

Studies on the Behavior and Mechanisms of Ivermectin in Electrospray Ionization Mass Spectrometry

作　　者：吴增茹[1] 朱丽荔[1] 骆宏鹏[1] 徐筱杰[1] 

机构地区：[1]北京大学化学与分子工程学院,北京100871

出　　处：《质谱学报》2001年第2期1-9,共9页Journal of Chinese Mass Spectrometry Society

基　　金：国家自然科学基金项目 2 95730 95资助

摘　　要：用电喷雾飞行时间质谱 (ESI TOF MS)研究了伊维菌素在ESI正、负离子检测方式下的加合和碎裂行为。正离子检测方式下的最佳有机溶剂浓度为5 0 %甲醇。在nozzle电压为 12 0V时 ,[M +NH4]+ 响应最强 ,而 [M +Na]+ 和 [M +K]+ 响应在 30 0V达最大值。伊维菌素在ESI MS中 ,得不到 [M +H]+ 峰。负离子的最佳有机溶剂浓度为 90 %甲醇 ,低nozzle电压时加合离子的强度很高 ,主要形成 [M +Cl]- 、[M +HCOO]- 、[M +CH3COO]- 和 [M +C3H5 O3]- ,加大nozzle电压 ,碎裂峰强度增加 ,主要是失掉一个氢 ,以及在此基础上再失掉一个或两个水分子、糖基 ,及反Diels Alder碎片的峰。当nozzle电压为 2 0 0V时 ,[M -H]- 峰达最大值。The adduct and fragmental behavior of ivermectin was studied in both positive and negative ion detection mode by using electrospray ionization time of flight mass spectrometry.The optimal organic solvent content for positive ion was 50∶50 methanol/water.The maximal intensity of [M+NH 4] + was achieved when nozzle potential was 120V,while the peaks of[M+Na] + and [M+K] + were highest at 300V.No peak of [M+H] + was observed in the positive ion detection mode of ivermectin.In negative ion detection mode,90∶10 methanol/water was the proper solvent.At lower nozzle potential,the high intensity of adduct ions were formed,which are [M+Cl] -,[M+HCOO] -,[M+CH 3COO] -and [M+C3H5O3] -.With the increasing nozzle potential,the intensity of fragmental ions were increased,which corresponded to the loss of H,the lose of one or two H 2O,sugar moieties of Diels Alder fragment ions from [M-H] -.When nozzle potential was 200V,the highest intensity of [M-H] - was achieved.

关 键 词：伊维菌素 电喷雾质谱 农药残留 分析 食品 加合 

分 类 号：TS207.53[轻工技术与工程—食品科学] O657.63[轻工技术与工程—食品科学与工程]