多杀菌素及其光照降解产物分析

Analyses of Spinosad and Its Degradates from Light Irradiation

采用五级质谱研究了多杀菌素的质谱断裂规律,应用串联质谱选择反应检测技术考察了光照条件下多杀菌素的降解程度,利用液相色谱-质谱联用手段分析了多杀菌素降解产物,并推断了主要降解产物的结构.结果表明,多杀菌素17碳上的福乐糖胺容易失去,三氧甲基鼠李糖很稳定;多杀菌素浓度随紫外光照射时间的增加而降低,在照射484min后,降解率达到70%左右,形成11种降解产物,这些降解产物是多杀菌素A或D经氧化、还原及水解等反应形成.

In this paper we report 5-stage mass spectrum fragmentations of spinosad under ultraviolet light irradiation was also investigated with mode. Degradates of spinosad were analyzed with liquid chromatography of spinosad A and D. Degrading rate selection reaction monitoring （ SRM ） coupling with mass spectrometry, and the chemical structures of main degradates were also assigned. It can be concluded that （ 1 ） forosamine on 17-carbon can be easily lost, but difficult for rhamnose sugar; （2） spinosad concentration decreased when irradiation time increased, degrading rate was up to about 70% for irradiating 484 min, and 11 degradates were produced. These degradates were products of the oxidation, reduction, and hydrolytic reactions.