Effect of variable ultraviolet wavelength and intensity on photochemical vapor generation of trace selenium detected by atomic fluorescence spectrometry

摘要

Selenium was taken as an example to investigate the effect of variable ultraviolet (UV) wavelength and intensity on its photochemical vapor generation (photo-CVG) process. A broadband laser-driven light source (LDLS) and a UV lamp were utilized as irradiation sources for the photo-CVG of trace selenium which was sensitively detected by atomic fluorescence spectrometry (AFS). Five filters with bandpass at different wavelength (254 nm, 285 nm, 315 nm, 365 nm and 395 nm) were used to filtrate the light from the LDLS and the UV lamp. The signal change of Se(VI) by photo-CVG-AFS was monitored when a TiO2-coated quartz coil was irradiated by variable wavelength and intensity. The experimental results indicated: (1) the efficiency of Se(VI) photo-CVG varied with irradiation wavelength; (2) a synergistic effect existed for the photo-CVG, and the efficiency of the full spectrum was thus better or close to the sum of all wavelengths; and (3) the efficiency of Se(VI) photo-CVG was also affected by the UV intensity.