Monitoring the TiO_2-Photocatalyzed Destruction of Aqueous Environmental Contaminants at Parts-per-trillion Levels Using Membrane Introduction Mass Spectrometry (MIMS)

摘要

Membrane introduction mass spectrometry (MIMS) was used to directly monitor the TiO_2/UV-photocatalyzed destruction of acetophenone, toluene, and chloroform in H_2O at ppm to pptr concentrations. The instrument response time was sufficiently rapid for these environmental contaminants (1–6 min) that “real-time” monitoring of their degradation was possible. This method was used to follow the loss of toluene at pptr levels and the concomitant formation of one of its primary photo-oxidation intermediates, methylphenol. These results illustrate the potential use of MIMS as a sensitive on-line measurement technique for monitoring photocatalytic destruction of trace organic contaminants in water at environmentally relevant levels.