Challenges nitrogen species measurements

The family of nitrogen compounds, by virtue of their number and complexity, has presented a series of challenges to the measurement community as the need to learn more about them has arisen because of their pivotal position in the chemistry of the atmosphere. A detailed description of the current ability to make measurements of known substances and the importance and possibility of the existence of as yet unmeasured species is presented in Chapter 9. In addition, the use of intercomparisons to verify and validate methods is discussed. 

Parrish Buhr Measurement Challenges of Nitrogen Species... 

This chapter focuses on several specific current challenges in the measurement of the nitrogen species. Examples of past results are included to give an indication of the insights into atmospheric processes that are potentially realizable from field studies. Many laboratories around the world are involved in these studies. The examples are drawn disproportionately from our laboratory simply for convenience. Although other examples can be cited, the ones included here are to a great extent representative of the field s results. 

B. Maim, G. E. Moore, K Roberts, L. J., II, Ischiropoulos, H. Measuring reactive oxygen and nitrogen species with fluorescent probes challenges and limitations. Free Radical Biol. Med. 2012, 52, 1-6. 

Atmospheric measurements are also challenging because they must deal with low to extremely low concentrations of trace chemical species. The major components (>99.999%) of the lowest portions of the atmosphere (the troposphere up to 10 km in altitude and the stratosphere between 10 and 50 km) are molecular nitrogen, molecular oxygen, argon, water vapor, and carbon dioxide. Chemists will recognize that all of these species are very stable, strongly bonded molecules or atoms that are essentially inert gases at normal atmospheric temperatures (190-310 K). Indeed, without solar photons to break up selected molecules, atmospheric chemistry would be very dull indeed. 

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