1. Micro Gas Analyzer Measurement of Nitric Oxide in Breath by Direct Wet Scrubbing and Fluorescence Detection
- Author
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Takahiro Koga, Mieko Kashiwagi, Takemi Arimoto, Kei Toda, Junichi Kosuge, and Hiroshi Oguchi
- Subjects
Detection limit ,Wet scrubber ,Chromatography ,Chemistry ,Fluorescence spectrometry ,Parts-per notation ,Analytical chemistry ,Scrubber ,Nitric Oxide ,Gas analyzer ,Analytical Chemistry ,chemistry.chemical_compound ,Spectrometry, Fluorescence ,Breath Tests ,Limit of Detection ,Feasibility Studies ,Fluorescein ,Nitrogen dioxide ,Wet chemistry ,Fluorescent Dyes - Abstract
A novel method is proposed to measure NO in breath. Breath NO is a useful diagnostic measure for asthma patients. Due to the low water solubility of NO, existing wet chemical NO measurements are conducted on NO(2) after removal of pre-existing NO(2) and conversion of NO to NO(2). In contrast, this study utilizes direct measurement of NO by wet chemistry. Gaseous NO was collected into an aqueous phase by a honeycomb-patterned microchannel scrubber and reacted with diaminofluorescein-2 (DAF-2). Fluorescence of the product was measured using a miniature detector, comprising a blue light-emitting diode (LED) and a photodiode. The response intensity was found to dramatically increase following addition of NO(2) into the absorbing solution or air sample. By optimizing the conditions, the sensitivity obtained was sufficient to measure parts per billion by volume levels of NO continuously. The system was applied to real analysis of NO in breath, and the effect of coexisting compounds was investigated. The proposed system could successfully measure breath NO.
- Published
- 2009
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