レーザ誘起ブレークダウン法を用いた排ガス中の微量成分計測

The rapid and precise element measurement technique of trace species, such as mercury, iodine, and strontium is important for various applications, especially for trace species analysis in exhausts. The trace elements such as mercury, iodine, arsenic, and strontium were measured by laser-induced breakdown spectroscopy (LIBS) and laser breakdown time-of-flight mass spectrometry (LB-TOFMS) for comparison of the corresponding detection features. Emissions and ion signals are detected by LIBS and LB-TOFMS to evaluate elemental composition. Multi-photon ionization and electron impact ionization in the plasma generation process can be controlled by the pressure and laser pulse width. 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. The detection systems of LIBS and LB-TOFMS can be selected depending on the condition of each application.