TRACE DETERMINATION OF BENZENE AND AROMATIC-MOLECULES IN HEXANE BY LASER 2-PHOTON IONIZATION

被引：36

作者：

OGAWA, T

KISE, M

YASUDA, T

KAWAZUMI, H

YAMADA, S

机构：

[1] Department of Molecular Science and Technology, Kyushu University, Fukuoka 816, Kasugashi

[2] Faculty of Literature, Kitakyushu University, Kokura-Minami

[3] College of General Education, Kyushu University, Chuo-ku

来源：

ANALYTICAL CHEMISTRY | 1992年 / 64卷 / 11期

关键词：

D O I：

10.1021/ac00035a005

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

Laser two-photon ionization of several aromatic molecules in hexane has been carried out with the fourth harmonics (266 nm) of a Nd-YAG laser as an excitation source. The photoionization current is quadratically proportional to the laser pulse energy, indicating two-photon ionization. There is a large blank signal due to the solvent (hexane) ionization, and it has been canceled with a differential technique. The effect of laser pulse energy fluctuation has been corrected by an on-line normalization procedure. The photoionization current also depends on the molar absorptivity of the molecule, and the first step to ionization should be excitation at 266 nm above the ground state. The detection limit ranges from 3.8 ppb for benzene to 61 ppt for pyrene. Analytical curves were linear for at least 3 orders of magnitude above the detection limits.

引用

页码：1217 / 1220

页数：4

共 20 条

[1] N-2-LASER INDUCED 2 PHOTON IONIZATION SPECTROMETRY FOR VITAMINS WITH A SIMPLE DC DETECTOR [J].