肌氨酸的真空紫外光光解：光电离质谱分析和理论研究。

Vacuum ultraviolet photofragmentation of sarcosine: photoionization mass spectrometric and theoretical insights.

机构信息

National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China.

出版信息

J Phys Chem A. 2010 Mar 18;114(10):3411-7. doi: 10.1021/jp9109095.

DOI:10.1021/jp9109095

PMID:20178350

Abstract

Vacuum ultraviolet (VUV) photon-induced ionization and fragmentation of N-methyl glycine (sarcosine) were investigated with infrared laser desorption/tunable synchrotron VUV photoionization mass spectrometry (IR LD/VUV PIMS) and theoretical calculations. Fragment-controllable mass spectra of sarcosine were measured at various photon energies. By tuning the photon energy, the fragments at m/z 44, 45, 43, 42, 30, and 60 were gradually detected. The ionization energy of the precursor was obtained by measuring the photoionization efficiency spectrum. Possible formation pathways of the fragment ions at m/z 44 (CH(3)NHCH(2)(+)), 45 (CH(3)NH(2)CH(2)(+)), 43 (CH(2)NHCH(2)(+)), 42 (CH(2)NCH(2)(+)), 30 (CH(2)NH(2)(+)), and 60 (CH(2)COOH(2)(+)) were discussed in detail with the help of calculations at the G3B3 and B3LYP/6-31++G(d,p) levels.

摘要

采用红外激光解吸/可调谐同步辐射真空紫外光电离质谱（IR LD/VUV PIMS）和理论计算研究了 N-甲基甘氨酸（肌氨酸）的真空紫外（VUV）光子诱导的离解和碎裂。在不同的光子能量下测量了肌氨酸的碎片可控质谱。通过调谐光子能量，逐渐检测到 m/z 44、45、43、42、30 和 60 的碎片。通过测量光电离效率谱获得了前体的电离能。借助 G3B3 和 B3LYP/6-31++G（d，p）水平的计算，详细讨论了 m/z 44（CH(3)NHCH(2)(+))、45（CH(3)NH(2)CH(2)(+))、43（CH(2)NHCH(2)(+))、42（CH(2)NCH(2)(+))、30（CH(2)NH(2)(+))和 60（CH(2)COOH(2)(+))碎片离子的可能形成途径。