Little Mark W, Kim Jae-Kuk, Murray Kermit K
Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
J Mass Spectrom. 2003 Jul;38(7):772-7. doi: 10.1002/jms.494.
Matrix-assisted laser desorption/ionization (MALDI) was performed using two pulsed lasers with wavelengths in the IR and UV regions. A 10.6 micro m pulsed CO(2) laser was used to irradiate a MALDI target, followed after an adjustable delay by a 337 nm pulsed nitrogen laser. The sample consisted of a 2,5-dihydroxybenzoic acid matrix and bovine insulin guest molecule. The pulse energy for both of the lasers was adjusted so that the ion of interest, either the matrix or guest ion, was not produced by either of the lasers alone. The delay time for maximum ion yield occurs at 1 micro s for matrix and guest ions and the signal decayed to zero in approximately 400 micro s. A mechanism is presented for enhanced UV MALDI ion yield following the IR laser pulse based on transient heating.
使用两个波长分别在红外和紫外区域的脉冲激光进行基质辅助激光解吸/电离（MALDI）。用一台10.6微米的脉冲CO₂激光照射MALDI靶，经过可调延迟后，再用一台337纳米的脉冲氮激光照射。样品由2,5 - 二羟基苯甲酸基质和牛胰岛素客体分子组成。调整两台激光的脉冲能量，使得感兴趣的离子，即基质离子或客体离子，不会仅由其中一台激光产生。基质离子和客体离子的最大离子产率的延迟时间出现在1微秒，信号在大约400微秒内衰减至零。提出了一种基于瞬态加热的机制，用于解释红外激光脉冲后紫外MALDI离子产率的增强。
