Abstract

Isotopic compositions of trace gases yield important information about their origin and can be used for process identification or as tracer. For example in ecosystem research isotopic ratios of CO₂, H_2O, N_2O NO and NO₂ are of interest as they enable to determine the source of, e.g., CO₂ (soil, plants, or combustion during energy conversion as a result of anthropogenic activity). In volcanic research isotopic ratios such as H³⁵C1/H³⁷Cl or¹³CO₂/¹²CO₂ are of special interest as magmatic gases may react with rocks and other fluids on their path to the earth surface. Hence, changes of isotopic ratios in emitted gases can serve as indicators of increased volcanic activity. A further area of isotope selective trace gas monitoring is in non-invasive medical diagnostics, e.g. isotope ratios of CO₂ have been identified as being indicators for the presence of Helicobacter pyroly, the bacteria associated with peptic ulcers and gastric cancer.

© 2007 IEEE