Quartz-enhanced photoacoustic spectroscopy (QEPAS) and Beat Frequency-QEPAS techniques for air pollutants detection: A comparison in terms of sensitivity and acquisition time

Biao Li; Giansergio Menduni; Marilena Giglio; Pietro Patimisco; Angelo Sampaolo; Andrea Zifarelli; Hongpeng Wu; Tingting Wei; Vincenzo Spagnolo; Lei Dong

doi:10.1016/j.pacs.2023.100479

Quartz-enhanced photoacoustic spectroscopy (QEPAS) and Beat Frequency-QEPAS techniques for air pollutants detection: A comparison in terms of sensitivity and acquisition time

Photoacoustics. 2023 Mar 23:31:100479. doi: 10.1016/j.pacs.2023.100479. eCollection 2023 Jun.

Authors

Biao Li^{1

2

3}, Giansergio Menduni³, Marilena Giglio³, Pietro Patimisco³, Angelo Sampaolo³, Andrea Zifarelli³, Hongpeng Wu^{1

2

3}, Tingting Wei^{1

2}, Vincenzo Spagnolo^{1

3}, Lei Dong^{1

2

3}

Affiliations

¹ State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China.
² Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China.
³ PolySense Lab - Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy.

Abstract

In this work, a comparison between Quartz Enhanced Photoacoustic Spectroscopy (QEPAS) and Beat Frequency-QEPAS (BF-QEPAS) techniques for environmental monitoring of pollutants is reported. A spectrophone composed of a T-shaped Quartz Tuning Fork (QTF) coupled with resonator tubes was employed as a detection module. An interband cascade laser has been used as an exciting source, allowing the targeting of two NO absorption features, located at 1900.07 cm^-1 and 1900.52 cm^-1, and a water vapor absorption feature, located at 1901.76 cm^-1. Minimum detection limits of 90 ppb and 180 ppb were achieved with QEPAS and BF-QEPAS techniques, respectively, for NO detection. The capability to detect multiple components in the same gas mixture using BF-QEPAS was also demonstrated.

Keywords: Air pollutants detection; BF-QEPAS; Multigas measurement; NO detection; QEPAS.