Abstract: The comparative study was carried out on RDA fragmentationof some derivatives of oxazinono-benzothiazepine under FAB and CI. It was found that the intensity ratio of product ions to protonated ion MH⁺ under FAB were significantly lower than that under CI. Itwas shown that the mechanism of protonation under FAB was quite different from that under CI. A proposal mechanism of protonation under FAB was discussed.

Key words: RDA fragmentation, FAB mechanism

摘要： 对一些嗪酮并苯并硫氮杂衍生物在FAB和CI条件下的RDA碎裂反应进行了比较研究。在FAB条件下，产物离子与质子化分子MH⁺的强度比明显低于CI。结果表明，FAB质子化机理与CI是不同的。本文对FAB质子化机理进行了探讨。

关键词: RDA碎裂, FAB机理