266nm下邻二甲苯双光子电离质谱的研究

Study on Two-photon Ionization Mass Spectra of O-xylene at the Laser of 266 nm

利用YAG激光器输出的四倍频激光对邻二甲苯分子的多光子电离过程进行了研究,获得了邻二甲苯分子的多光子电离飞行时间质谱(MPI-TOFMS),其母体离子及碎片离子信号达22种之多。光强指数分析表明母体离子C8H+10和主要的碎片离子C7H+7、C6H+5发生了1+1共振增强双光子电离(RE2MPI)。

Multiphoton ionization process of o-xylene is studied Using the four-harmonic YAG 1aser as excitation source,and time-of-flight mass spectrometer of o-xylene are obtained. Parent ion and fragment ion reach as much as 22 kinds. The result of laser power index shows that the parent-ion C8H^＋10and major fragment ions C7H^＋7and C6H^＋5undergo the 1 ＋ 1 resonant enhanced two-photon ionization（ RE2PI） process.