Comparison of the Detection Characteristics of Trace Species Using Laser-Induced Breakdown Spectroscopy and Laser Breakdown Time-of-Flight Mass Spectrometry

Sensors

Zhenzhen Wang²  Yoshihiro Deguchi¹  Junjie Yan²  Jiping Liu² 

[1] Graduate School of Advanced Technology and Science, the University of Tokushima, 2-1, Minamijyosanjima, Tokushima 770-8506, Japan;State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, No.28, Xianning West Road, Xi’an 710049, China; E-Mails:

关键词: laser-induced breakdown spectroscopy (LIBS);    laser breakdown time-of-flight mass spectrometry (LB-TOFMS);    low pressure;    electron impact ionization;   

DOI  :  10.3390/s150305982

来源: mdpi

【 摘 要 】

The rapid and precise element measurement of trace species, such as mercury, iodine, strontium, cesium, etc. is imperative for various applications, especially for industrial needs. The elements mercury and iodine were measured by two detection methods for comparison of the corresponding detection features. A laser beam was focused to induce plasma. Emission and ion signals were detected using laser-induced breakdown spectroscopy (LIBS) and laser breakdown time-of-flight mass spectrometry (LB-TOFMS). Multi-photon ionization and electron impact ionization in the plasma generation process can be controlled by the pressure and pulse width. The effect of electron impact ionization on continuum emission, coexisting molecular and atomic emissions became weakened in low pressure condition. When the pressure was less than 1 Pa, the plasma was induced by laser dissociation and multi-photon ionization in LB-TOFMS. According to the experimental results, the detection limits of mercury and iodine in N₂ were 3.5 ppb and 60 ppb using low pressure LIBS. The mercury and iodine detection limits using LB-TOFMS were 1.2 ppb and 9.0 ppb, which were enhanced due to different detection features. The detection systems of LIBS and LB-TOFMS can be selected depending on the condition of each application.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.