Abstract
A Fourier transform infrared (FT-IR) spectroscopy based gas sensor for continuous analysis of liquid phase samples has been developed, coupling a short hollow waveguide (HWG) gas cell with a supported capillary membrane sampler (SCMS) probe. Passing an inert carrier gas through the thin-walled tubular silicon membrane enables the permeation of volatile organic compounds (VOCs) present in aqueous solution and facilitates their continuous and quantitative detection in the infrared hollow fiber by multiple internal reflection spectroscopy. The sensitivity of the sensor system has been determined at the ppb (μg/L) concentration level and the response time ranges from few minutes to 30 min, depending on the analyte and the permeation properties of the sampling membrane. The experimental set-up consists of Bruker Vector 22 FT-IR spectrometer with an externally aligned 50 cm long silica HWG coupled to the SCMS, which is immersed into a glass flask filled with analyte solution and kept under constant stirring. Aqueous solutions of benzene, toluene, xylene isomers and chloroform were qualitatively and quantitatively analyzed confirming the feasibility of this sensor approach for environmental analysis.
Original language | English |
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Pages (from-to) | 573-583 |
Number of pages | 11 |
Journal | International Journal of Environmental Analytical Chemistry |
Volume | 83 |
Issue number | 7-8 |
DOIs | |
State | Published - Jul 2003 |
Keywords
- Capillary membrane sampler
- FT-IR
- Hollow waveguide
- IR sensor
- Volatile organic compounds (VOCs)
- Water analysis