Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele St, Toronto, ON, Canada, M3J 1P3.
Rapid Commun Mass Spectrom. 2010 Aug 15;24(15):2262-8. doi: 10.1002/rcm.4633.
Ultraviolet photodissociation (UVPD) was evaluated as a technique for generating ion fragmentation information that is alternative and/or complementary to the information obtained by collision-induced dissociation (CID). Ions trapped in a pressurized linear ion trap were dissociated using a 355 nm or a 266 nm pulsed laser. Comparisons of UVPD and CID spectra using a set of aromatic chromophore-containing compounds (desmethyl bosentan, haloperidol, nelfinavir) demonstrated distinct characteristic fragmentation patterns resulting from photodissociation. The wavelength of light and the pressure of the buffer gas in the UVPD cell are important parameters that control fragmentation pathways. The wavelength effect is related to the absorption cross section, location of the chromophore and the energy carried by one photon. Thus, UV irradiation wavelength affects fragmentation pathways as well as the fragmentation rate. The pressure effect can be explained by collisional quenching of 'slow' fragmentation pathways. We observed that higher pressure of the buffer gas during UVPD experiments highlights unique fragment ions by suppressing slow fragmentation pathways responsible for CID-like fragmentation patterns.
紫外线光解（UVPD）被评估为一种产生离子碎片化信息的技术，这种信息可作为与碰撞诱导解离（CID）获得的信息互为补充或互为替代。使用 355nm 或 266nm 脉冲激光将被困在加压线性离子阱中的离子进行解离。使用一组含有芳香族发色团的化合物（去甲博沙坦、氟哌啶醇、奈非那韦）对 UVPD 和 CID 光谱进行比较，结果表明光解会产生截然不同的特征碎片化模式。UVPD 单元中光的波长和缓冲气体的压力是控制碎片化途径的重要参数。波长效应与吸收截面、发色团的位置以及一个光子所携带的能量有关。因此，UV 辐照波长会影响碎片化途径和碎片化速度。压力效应可以通过“缓慢”碎片化途径的碰撞猝灭来解释。我们观察到，在 UVPD 实验中增加缓冲气体的压力可以通过抑制导致 CID 样碎片化模式的缓慢碎片化途径来突出独特的碎片离子。
