Hydrogen peroxide detection with quartz-enhanced photoacoustic spectroscopy using a distributed-feedback quantum cascade laser

摘要

A quartz-enhanced photoacoustic spectroscopy sensor system was developed for the sensitive detection of hydrogen peroxide (H_2O_2) using its absorption transitions in the v_6 fundamental band at ～7.73 μm. The recent availability of distributed-feedback quantum cascade lasers provides convenient access to a strong H_2O_2 absorption line located at 1295.55 cm~(-1). Sensor calibration was performed by means of a water bubbler that generated titrated average H_2O_2 vapor concentrations. A minimum detection limit of 12 parts per billion (ppb) corresponding to a normalized noise equivalent absorption coefficient of 4.6 × 10~(-9)cm~(-1)W/Hz~(1/2) was achieved with an averaging time of 100 s.