在气体染色学/甲化学电离精确质谱学中将分子离子物种自动分配到元素公式中
Shunyang Wang1,2, Luis Valdiviez2, Honglian Ye2
1Department of Chemistry, University of California, Davis, CA 95616, USA.
Metabolites
|August 25, 2023
概括
甲化学电离与GC-QTOF质谱学相结合,有效地识别了未知代谢物的分子公式. 这种方法利用三甲基化衍生物,有助于表征在光谱库中缺少的化合物.
科学领域:
- 代谢学 代谢学 代谢学
- 分析化学 分析化学
- 质谱测量质量谱测量
背景情况:
- 传统的气相色谱-质谱学 (GC-MS) 与电子电离产生广泛的碎片化,阻碍了由于缺乏分子离子物种而缺乏库匹配的未知化合物的识别.
- 三甲基化 (TMS) 衍生是一种常见的技术,用于提高代谢物的挥发性和可检测性.
- 四极飞行时间 (QTOF) 质谱仪提供了高质量精度,对于确定元素组成至关重要.
研究的目的:
- 评估甲化学电离 (MCI) 与GC-QTOF质谱相结合,用于识别三甲基化 (TMS) 衍生代谢物的分子公式.
- 使用SIRIUS软件开发和评估用于检测分子离子物种和确定分子公式的自动化算法.
- 在MCI-GC-QTOF分析衍生代谢物的过程中,研究新的 adduct 形成和碎片化模式.
主要方法:
- 在GC-QTOF质谱仪上使用甲化学电离的369种TMS衍生代谢物的分析.
- 开发一种自动化工作流程,用于检测分子离子物种和添加物.
- 应用SIRIUS软件用于精确的分子公式确定和根据已知的标准进行验证.
主要成果:
- 自动化工作流成功地识别了84% (289/345) 的检测到的衍生标准中的分子离子物种.
- 在85% (290/345) 的化合物中观察到强烈的[M - CH3]+片段,促进了自动引导模式识别.
- 对于87%的分析化合物,Sirius软件准确地检索了前三名中正确的元素公式.
- 在几种自动化分析失败的代谢物中,通过重新排列形成了以前未知的[M + TMS] + adduct.
结论:
- 甲化学电离与GC-QTOF质谱相结合是一种强大的方法,用于确定代谢学中大量未知峰值的分子公式.
- 开发的自动化工作流程和SIRIUS软件在识别TMS衍生代谢物的分子公式方面表现出高准确性.
- 在MCI-GC-QTOF分析中发现了一种新的[M + TMS]+添加物,为碎片化机制提供了新的见解.
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