Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jul 2;21(13):4548.
doi: 10.3390/s21134548.

Ultra-Highly Sensitive Ammonia Detection Based on Light-Induced Thermoelastic Spectroscopy

Yao Mi  1 , Yufei Ma  1
Affiliations

Ultra-Highly Sensitive Ammonia Detection Based on Light-Induced Thermoelastic Spectroscopy

Yao Mi et al. Sensors (Basel). .

Abstract

This invited paper demonstrated an ultra-highly sensitive ammonia (NH3) sensor based on the light-induced thermoelastic spectroscopy (LITES) technique for the first time. A quartz tuning fork (QTF) with a resonance frequency of 32.768 kHz was employed as a detector. A fiber-coupled, continuous wave (CW), distributed feedback (DFB) diode laser emitting at 1530.33 nm was chosen as the excitation source. Wavelength modulation spectroscopy (WMS) and second-harmonic (2f) detection techniques were applied to reduce the background noise. In a one scan period, a 2f signal of the two absorption lines located at 6534.6 cm-1 and 6533.4 cm-1 were acquired simultaneously. The 2f signal amplitude at the two absorption lines was proved to be proportional to the concentration, respectively, by changing the concentration of NH3 in the analyte. The calculated R-square values of the linear fit are equal to ~0.99. The wavelength modulation depth was optimized to be 13.38 mA, and a minimum detection limit (MDL) of ~5.85 ppm was achieved for the reported NH3 sensor.

Keywords: ammonia (NH3); light-induced thermoelastic spectroscopy (LITES); quartz tuning fork (QTF); trace gas detection.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Emission characteristic of the 1530.33 nm CW-DFB diode laser.
Figure 2
Figure 2
Simulation absorption spectra based on HITRAN database: (a) absorption line strength of different gases; (b) absorption coefficient of NH3 at 296 K, standard atmospheric pressure, and an optical path length of 1 cm for 10,000 ppm NH3:N2.
Figure 3
Figure 3
Schematic diagram of the LITES sensor system.
Figure 4
Figure 4
Normalized and squared amplitude as a function of frequency.
Figure 5
Figure 5
The correlation between normalized 2f signal value and ventilation time.
Figure 6
Figure 6
The correlation between wavelength modulation depth and 2f signal value.
Figure 7
Figure 7
(a) 2f signal of 10,000 ppm NH3:N2; (b) noise level of NH3-LITES sensor.
Figure 8
Figure 8
2f signal of mixture gas with different NH3 concentrations.
Figure 9
Figure 9
Linear fits of 2f signal peak values and NH3 concentration.
See this image and copyright information in PMC

References

    1. Jiménez I., Vilà A.M., Calveras A.C., Morante J.R. Gas sensing properties of catalytically modified wo3 with copper and vanadium for NH3 detection. IEEE Sens. J. 2002;5:385–391. doi: 10.1109/JSEN.2005.846175. - DOI
    1. Guntner A.T., Abegg S., Konigstein K., Gerber P.A., Schmidt-Trucksäss A., Pratsinis S.E. Breath sensors for health mon-itoring. ACS Sens. 2019;4:268–280. doi: 10.1021/acssensors.8b00937. - DOI - PubMed
    1. Narasimhan L.R., Goodman W., Patel C.K.N. Correlation of breath ammonia with blood urea nitrogen and creatinine during hemodialysis. Proc. Natl. Acad. Sci. USA. 2001;98:4617–4621. doi: 10.1073/pnas.071057598. - DOI - PMC - PubMed
    1. Fedoruk M.J., Bronstein R., Kerger B.D. Ammonia exposure and hazard assessment for selected household cleaning product uses. J. Expo. Anal. Sci. Environ. Epidemiol. 2005;15:534–544. doi: 10.1038/sj.jea.7500431. - DOI - PubMed
    1. Majder-Łopatka M., Węsierski T., Dmochowska A., Salamonowicz Z., Polańczyk A. The Influence of Hydrogen on the Indications of the Electrochemical Carbon Monoxide Sensors. Sustainability. 2019;12:14. doi: 10.3390/su12010014. - DOI

LinkOut - more resources