Application of a Pulsed Dye Laser to Polarization Spectroscopy for Elemental Analysis

摘要

Pulsed dye laser polarization spectroscopy is applied to elemental analysis in flames. The approach involved the detection of a coherent beam of light (dye laser), and so the detector could be situated far away from the sampled point (120 cm in our case). In this way, the solid angle defined by the detector could be made very small, and the contribution to the background from fluorescence, scatter, and/or emission become negligible. By the nebulization of 1000 mg/L solutions of Na and Al (as A1C13) into the flame to check for fluorescence and scatter in the presence of the pump beam (no probe beam), no measurable change in the background could be observed. The limit of detection for Na (S/N = 3) was found to be 2 mg/L for averaging 3000 pulses. It must be pointed out that this limit of detection was obtained with a maximum achievable extinction ratio of only 200.