Real time ammonia detection in exhaled human breath using a distributed feedback quantum cascade laser based sensor

Content Provider	Semantic Scholar
Author	Rafa Lewicki, Rafał Kosterev, Anatoliy Thomazy, David M. Risby, Terence H. Solga, Steven Francis Schwartz, Timothy J. Perfect Bennett L. Tittel, Frank K.
Copyright Year	2010
Abstract	A continuous wave, thermoelectrically cooled, distributed feedback quantum cascade laser (DFB-QCL) based sensor platform for the quantitative detection of ammonia (NH3) concentrations present in exhaled human breath is reported. The NH3 concentration measurements are performed with a 2f wavelength modulation quartz enhanced photoacoustic spectroscopy (QEPAS) technique, which is very well suited for real time breath analysis, due to the fast gas exchange inside a compact QEPAS gas cell. An air-cooled DFB-QCL was designed to target the interference-free NH3 absorption line located at 967.35 cm (λ~10.34 μm). The laser is operated at 17.5 °C, emitting ~ 24 mW of optical power at the selected wavelength. A 1σ minimum detectable concentration of ammonia for the line-locked NH3 sensor is ~ 6 ppb with 1 sec time resolution. The NH3 sensor, packaged in a 12′′x14′′x10′′ housing, is currently installed at a medical breath research center in Bethlehem, PA and tested as an instrument for non-invasive verification of liver and kidney disorders based on human breath samples.
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://lasersci.blogs.rice.edu/files/2014/05/LewickiPW2011.pdf
Language	English
Access Restriction	Open
Subject Keyword	Ammonia measurement Breath Tests Cascade Device Component Expiration, function Interference (communication) Kidney Diseases Modulation Photoacoustic Spectroscopy Quartz Sensor Verification of Theories wavelength
Content Type	Text
Resource Type	Article