Miniature open channel scrubbers for gas collection

• Published in: Talanta (Oxford) 2010-10, Vol.82 (5), p.1870-1875
• Main Authors: Toda, Kei, Koga, Tomoko, Tanaka, Toshinori, Ohira, Shin-Ichi, Berg, Jordan M., Dasgupta, Purnendu K.
• Format: Article
• Language: English
• Subjects: Absorption; Adsorption; Air Pollutants - analysis; Algorithms; Ammonia; Ammonia - analysis; Analytical chemistry; Channels; Chemistry; Chromatographic methods and physical methods associated with chromatography; Collection; Computational efficiency; Computing time; Environmental Monitoring - instrumentation; Environmental Monitoring - methods; Equipment Design; Exact sciences and technology; Gases - analysis; Hydrogen sulfide; Hydrogen Sulfide - analysis; Japan; Membranes; Membranes, Artificial; Miniature; Miniature device for gas collection; Other chromatographic methods; Planar channel gas scrubber; Polyvinyl Chloride - chemistry; Scrubbers; Spectrometric and optical methods; Sulfur dioxide; Sulfur Dioxide - analysis; Theoretical simulation of gas collection; Volcanic Eruptions - analysis
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2010.08.001

An open channel scrubber is proposed as a miniature fieldable gas collector. The device is 100 mm in length, 26 mm in width and 22 mm in thickness. The channel bottom is rendered hydrophilic and liquid flows as a thin layer on the bottom. Air sample flows atop the appropriately chosen flowing liquid film and analyte molecules are absorbed into the liquid. There is no membrane at the air–liquid interface: they contact directly each other. Analyte species collected over a 10 min interval are determined by fluorometric flow analysis or ion chromatography. A calculation algorithm was developed to estimate the collection efficiency a priori; experimental and simulated results agreed well. The characteristics of the open channel scrubber are discussed in this paper from both theoretical and experimental points of view. In addition to superior collection efficiencies at relatively high sample air flow rates, this geometry is particularly attractive that there is no change in collection performance due to membrane fouling. We demonstrate field use for analysis of ambient SO 2 near an active volcano. This is basic investigation of membraneless miniature scrubber and is expected to lead development of an excellent micro-gas analysis system integrated with a detector for continuous measurements.