| Photo-induced chemical/cold vapor generation (PI-CVG) system was used to produce mercury cold vapor, which was determined by atomic fluorescence spectrometry after gas/liquid separation. Under the UV radiation, Hg2+ in aqueous solution can be converted into Hg0 cold vapor by using an organic reactant of low molecular weight alcohols, aldehydes or carboxylic acids, namely, methanol, formaldehyde, acetaldehyde, glycol, 1,2-propanediol, glycerol, acetic acid, oxalic acid or malonic acid. It was found that the presence of nano-TiO2 nanoparticles (nano-TiO2 later) enhanced the efficiency of the PI-CVG system.Under the optimized experimental conditions, the limits of detection (based on three standard deviation of 11 measurements of a blank solution) were around 0.02 to 0.04μg/L, with linear dynamic ranges up to 15μg/L. Also discussed in detail were the interference of transition metals, generation efficiency in above mentioned nine systems and the mechanisms of the PI-CVG system. Preliminary analytical application of the PI-CVG-AFS revealed that it was very promising for water analysis for ultra low level of mercury. Besides, the nano-TiO2 enhanced PI-CVG can be potentially useful for the disposal of mercury-polluted wastewater in the environmental area. The degradation efficiency of mercury (100 ? g/L) with a simulated wastewater approached 100% after 6 hours.
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