Ambient air. Standard method for the measurement of the concentration of nitrogen dioxide and nitrogen monoxide by chemiluminescence

2020 ◽  
Author(s):  
Robert Wegener ◽  

<p>Nitrogen dioxide (NO<sub>2</sub>) and nitrogen monoxide (NO) govern the photochemical processes in the troposphere. Although nitrogen oxides have been measured for decades, their quantification remains challenging. The MetNO2 (Metrology for Nitrogen Dioxide) project of the European Metrology Programme for Innovation and Research (EMPIR) aims to improve the accuracy of NO<sub>2</sub> measurements.</p><p>In total 15 instruments were intercompared at the World Calibration Centre for nitrogen oxides (WCC-NOx) in Jülich in autumn 2019 within the project. In addition to chemiluminescence detectors (CLD), the instruments encompassed Quantum Cascade Laser Absorption Spectrometers (QCLAS), Iterative CAvity-enhanced Differential optical absorption spectrometers (ICAD) and Cavity Attenuated Phase Shift (CAPS) spectrometers.</p><p>During the campaign, air from a gas phase titration unit, air from the environmental chamber SAPHIR or outside air was provided to the instruments via a common inlet line. The participants calibrated their instruments prior and after the campaign with their own calibration procedures. During the campaign, the common inlet line was used for daily calibration to compare standards, calibration techniques and sensitivity drifts of the instruments. NO<sub>2</sub> for calibration was provided either by gas phase titration from NO, from permeation tubes or from gas mixtures produced within the MetNO2 project.</p><p>It was observed that measurements by chemiluminescence or CAPS instruments are prone to interferences from humidity and ozone. However, in most cases data can be corrected. Alkyl nitrates and reactive alkenes were also observed to cause interferences in some instruments, while isobutyl nitrite was found to be photolyzed by photolytic converters.</p><p>Finally, measurements in ambient air were compared. The nitrogen oxide observations were accompanied with measurements of hydroxyl radical (OH) reactivity and reactive nitrogen species as nitrous acid (HONO), dinitrogen pentoxide (N<sub>2</sub>O<sub>5</sub>), and chloryl nitrate (ClNO<sub>2</sub>). Detailed results of the intercomparison will be presented.</p>


Author(s):  
Z.B. Baktybaeva ◽  
R.A. Suleymanov ◽  
T.K. Valeev ◽  
N.R. Rahmatullin ◽  
E.G. Stepanov ◽  
...  

Introduction. High density of oil-producing and refining facilities in certain areas of Bashkortostan significantly affects the environment including ambient air quality in residential areas. Materials and methods. We analyzed concentrations of airborne toxicants (sulfur and nitrogen oxides, nitrogen and carbon oxides, hydrogen sulfide, ammonia, xylenes, toluene, phenol and total suspended particles) and population health status in the cities of Ufa, Sterlitamak, Salavat, Blagoveshchensk, and the Tuymazinsky District in 2007–2016. Pearson's correlation coefficients (r) were used to establish possible relationships between medico-demographic indicators and air pollution. Results. Republican fuel and energy enterprises contributed the most to local air pollution levels. Gross emissions from such enterprises as Bashneft-Ufaneftekhim and Bashneft-Navoil reached 43.69–49.77 thousand tons of pollutants per year. The levels of some air pollutants exceeded their maximum permissible concentrations. Elevated concentrations of ammonia, total suspended particles, nitrogen dioxide, and carbon monoxide were registered most frequently. High rates of congenital abnormalities, respiratory diseases in infants (aged 0-1), general mortality and morbidity of the population were observed in some oil-producing and refining areas. The correlation analysis proved the relationship between the concentration of carbon monoxide and general disease rates in adults based on hospital admissions (r = 0.898), general incidence rates in children (r = 0.957), and blood disease rates in infants (r = 0.821). Respiratory diseases in children correlated with nitrogen dioxide emission levels (r = 0.899). Conclusions. Further development of oil-producing, petrochemical and oil-refining industries should be carried out taking into account socio-economic living conditions of the population.


2013 ◽  
Vol 3 (3) ◽  
pp. 250-254
Author(s):  
Suad Habeš ◽  
Zarema Obradović ◽  
Aida Ridžal ◽  
Asmir Aldžić

Introduction: Air pollution occurs when the concentration of certain substances (pollutants) reaches a size which causes its toxicity, or in other words, begins to cause harm to human health, fl ora and wildlife.Methods: Measurements were performed in the period from 2005 to 2010, at the measuring point Bjelave-Sarajevo by the method of Griess-Saltzmann. It encompasses the following parameters: NO, NO2, NOx, measured concentrations of pollutants in the atmosphere reduced to normal atmospheric conditions of 293 K (Kelvin) and pressure of 101.3 kPa (kilopascal).Results: NO concentration in the period from 2005 to 2008 was above the permitted value, but the results of research in the period between 2009 and 2010, have shown that there was a decrease in NO concentration in the atmosphere. Measurements show that the concentration of this pollutant is currently declining, which is a positive result compared to the pollution of the atmosphere by nitrogen monoxide. Furthermore, the results of the research showed that the concentration of NO2 for the period of 2005 to 2010, is in the limited values, and that has a decreasing trend, which is also a positive result compared to the pollution of the atmosphere by nitrogen dioxide. Related to the total concentration of NOx in the atmosphere, the results of the research show that their representation corresponds to the limit values existing in the Rulebook on limit values for air quality.Conclusion: The results of the research for the pollution of the atmosphere by nitrogen oxides in the investigated area show that the amount of nitrogen oxides in the atmosphere is in constant decline.


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