UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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Conference: Bucharest University Faculty of Physics 2001 Meeting


Section: Optics and Spectroscopy


Title:
Monitoring of NO2 in air samples by FTIR Spectroscopy


Authors:
A. Staicu, L. Voicu, I. Iova*, M.L. Pascu, A. Pascu


Affiliation:
National Institute for Lasers, Plasma and Radiation Physics

Lasers Department, Bucharest

*University of Bucharest, Faculty of Physics, Optics. Spectroscopy. Plasma. Lasers Department, Bucharest


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Keywords:


Abstract:
Measurements of NO2 in air samples laboratory made were performed by Fourier Transform Infrared Spectroscopy. FTIR is a high sensitive technique used for molecule identification by the vibrational specific bands of their functional groups and also for quantitative detection via Lambert-Beer absorption law. This method was used here for samples prepared in laboratory by chemical reaction: between Cu and HNO3. Beside NO2 and air the samples also contain other oxides NOx, founded in chemical equilibrium with NO2. FTIR thechnique was choose for these oxides identification and also for establishing the content in NO2 of the samples. In this purpose, FTIR spectra of samples at different total pressures between 50torr-250torr were recorded by a Magna 550, Nicolet spectrometer in the range 600cm-1-4000cm-1 with 4cm-1 resolution. For the assignment of the spectral bands obtained, it was used the HITRAN’96 database performed by Harvard Smithsonian Center for Astrophysics. In the FTIR measured spectra , vibrational bands specific to NO2 , air components as CO2 , H2O and nitrogen oxides as N2O were identified. For quantification of the NO2 content, it was used the vibrational absorption band (011-010) at 1605cm-1. The band peak intensities function of samples pressure were fitted with a line in order to obtain the calibration curve. From the slope of it was extracted a 38% content of samples in NO2. FTIR demonstrated its facilities for gas samples analyzing and also for quantitative measurements with high accuracy and sensitivity. This work was supported by a grant from The National Agency for Science, Technology and Innovation (ANSTI).