Abstract
The construction, optimization and application are described for a portable gas analyzer which gives real-time measurement of sulfur dioxide in a gas stream. The SO2 is absorbed from the analyte gas stream into a gravity-driven carrier solution flowing through a diffusion scrubber (DS), in the form of a bundle of polymeric hollow fibers. The sulfite ions in the carrier solution are detected by anodic amperometry at a novel carbon nanotube (CNT) electrode polarized at 0.35 V vs Ag/AgCl reference electrode. A novel compact design is the result of integrating the DS with the amperometric detector and yields a light weight portable analyzer (900 g) with a small footprint. The optimized analyzer has favorable performance characteristics such as (i) good sensitivity (LOD = 4 ppm, S/N = 3), (ii) wide linear dynamic range up to 5000 ppm, (iii) reasonably fast response time (t95%, 4.1 min), (iv) excellent signal stability and repeatability (RSD = 1.3%), and (v) continuous standalone operation for 6 h. The interfering effect of H2S is avoided by removing H2S using a prior guard column. The analyzer can successfully monitor the removal of SO2 from SO2-N2 gas mixtures and in determining sulfite in foodstuffs.
Original language | English |
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Pages (from-to) | 24-33 |
Number of pages | 10 |
Journal | Sensors and Actuators, B: Chemical |
Volume | 225 |
DOIs | |
Publication status | Published - Mar 31 2016 |
Keywords
- Amperometry
- CNT
- Hollow fiber membrane contactors
- Portable gas analyzer
- SO determination
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry