Fragmentation of vitamin B12 during 337 nm matrix-assisted laser desorption ionization
Fragmentation of vitamin B12 during 337 nm matrix-assisted laser desorption ionization
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337 nm 基质辅助激光解吸电离过程中维生素 B12 的裂解
DOI：
10.1002/bms.1200230404
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发表时间：
1994
影响因子：
2.3
通讯作者：
D. Russell
中科院分区：
文献类型：
--
作者：
G. Kinsel;L. M. Preston;D. Russell
当使用基质α-氰基-4-羟基肉桂酸时，维生素B12在337 nm处的基质辅助激光解吸电离在飞行时间质谱中产生低丰度的质子化分子。在飞行时间质谱中观察到各种碎片离子，这些碎片离子可以根据以前对维生素B12碎片化的研究进行分配。当使用基质4-羟基-3-碘-5-硝基苯甲酸时，产生来自维生素B12的质子化分子离子的丰富信号。在飞行时间质谱中仍然观察到碎片离子，但丰度要低得多。基质与分析物的比例和解吸激光强度的影响的研究反对直接光解碎片离子形成的机制。基质的选择似乎最强烈地影响激光解吸离子的内能，从而控制碎裂过程。
Matrix-assisted laser desorption ionization of vitamin B12 at 337 nm yields low abundances of the protonated molecule in time-of-flight mass spectra when the matrix α-cyano-4-hydroxycinnamic acid is used. A variety of fragment ions are observed in the time-of-flight mass spectra which may be assigned on the basis of previous studies of vitamin B12 fragmentation. When the matrix 4-hydroxy-3-iodo-5-nitrobenzoic acid is used, an abundant signal from the protonated molecule ion of vitamin B12 is produced. Fragment ions are still observed in the time-of-flight mass spectra but at much lower abundances. Studies of the influence of matrix-to-analyte ratio and desorbing laser intensity argue against direct photodissociation as the mechanism of fragment ion formation. Matrix choice appears to most strongly influence the internal energies of the laser-desorbed ions thereby controlling the fragmentation processes.