Breath methane detection based on all-optical photoacoustic spectrometer.

A novel approach for breath methane monitoring is presented, which employs an all-optical photoacoustic spectrometer based on a distributed feedback (DFB) laser diode and a fiber acoustic sensor. To avoid the interference of high concentration of CO 2 and H 2 O at atmospheric pressure, the 1650.96 nm absorption line for CH 4 is selected. The minimum detection limit of 64 ppb (signal-to-noise ratio = 3) in simulated breath samples (4% CO 2 and 6% H 2 O (100% relative humidity at 37 °C)) is achieved. [ABSTRACT FROM AUTHOR]