Sensing of halocarbons using femtosecond laser-induced fluorescence

Anal Chem. 2004 Aug 15;76(16):4799-805. doi: 10.1021/ac049425k.

Abstract

A femtosecond laser-induced clean fluorescence technique was explored as a means to monitor halogenated alkanes in the atmosphere. Characteristic difluorocarbene radical (CF2) fluorescence in the UV-vis can be generated inside a femtosecond laser-induced filament for different halocarbons. We show that, due to different dissociation and excitation kinetics leading to fluorescence emission, it is possible to temporally resolve the characteristic fluorescence of CF2-containing halocarbons from that of background species, therefore enhancing the signal-to-noise ratio. Laboratory-scale experiments demonstrate the potential use of femtosecond laser-induced clean fluorescence for the remote sensing of halocarbons in the atmosphere. The combination of this detection strategy with LIDAR could allow the long-range monitoring of several atmospheric species with a single laser source, eventually leading to a better understanding of chemical and dynamic processes affecting global warming, ozone loss, tropospheric pollution, and weather prediction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calibration
  • Hydrocarbons, Fluorinated / analysis
  • Hydrocarbons, Halogenated / analysis*
  • Kinetics
  • Lasers
  • Spectrometry, Fluorescence / methods

Substances

  • Hydrocarbons, Fluorinated
  • Hydrocarbons, Halogenated
  • difluorocarbene