Photoacoustic spectroscopy using a quantum cascade laser for analysis of ammonia in water solutions

0587074 - FZÚ 2025 RIV US eng J - Journal Article
Apostolakis, Apostolos - Aoust, G. - Maisons, G. - Laurent, L. - Pereira, Mauro Fernandes
Photoacoustic spectroscopy using a quantum cascade laser for analysis of ammonia in water solutions.
ACS Omega. Roč. 9, č. 17 (2024), s. 19127-19135. ISSN 2470-1343. E-ISSN 2470-1343
EU Projects: European Commission(XE) 832876 - aqua3S; European Commission(XE) 101021857 - ODYSSEUS
Institutional support: RVO:68378271
Keywords : absorption * ammonia * computer simulations * molecules * sensors * photoacoustic detection * NEGF * QCL
OECD category: Optics (including laser optics and quantum optics)
Impact factor: 4.1, year: 2022
Method of publishing: Open access

Ammonia (NH3) toxicity, stemming from nitrification, can adversely affect aquatic life and influence the taste and odor of drinking water. This underscores the necessity for highly responsive and accurate sensors to continuously monitor NH3 levels in water, especially in complex environments where reliable sensors have been lacking until this point. Herein, we detail the development of a sensor comprising a compact and selective analyzer with low gas consumption and a timely response, based on photoacoustic spectroscopy. This, combined with an automated liquid sampling system, enables the precise detection of ammonia traces in water. The sensor system incorporates a state-of-the art quantum cascade laser as the excitation source emitting at 9 μm in resonance with the absorption line of NH$_3$ located at 1103.46 cm$^{-1}$. Our instrument demonstrated detection sensitivity at low ppm level for ammonia molecule with response times less than 60 seconds. For the sampling system, an ammonia stripping solution was designed resulting in a prompt full measurement cycle (6.35 min). A further evaluation of the sensor within a pilot study showed good reliability and agreement with the reference method for real water samples, confirming the potential of our NH3 analyzer for water-quality monitoring applications.
Permanent Link: https://hdl.handle.net/11104/0354376