Analytical system for carbon stable isotope measurements of light non-methane hydrocarbons

Abstract

Abstract. Isotope analysis can be a useful tool in constraining the budgets (sources and sinks) of atmospheric trace species and is increasingly applied for organic constituents. This may be useful in particular for investigating the oxidative capacity of the atmosphere and studying long-range. We present setup, testing and initial results from a new automated system for carbon stable isotope ratio measurements on C2 to C6 atmospheric hydrocarbons. The inlet system is flexible and allows analysis of trace gases from medium size to very large ambient air samples (5–300 L) without loss of compounds of interest. The first application of this system was the analysis of ambient air during a short campaign in August 2009 in Utrecht, the Netherlands. Results obtained agree well with previous research, but highlight the complex diurnal behavior of hydrocarbons in an urban environment.