Most analytical methods described previously for the monitoring
of N2O are based on gas chromatographic techniques.
Environmental studies have reported the use of gas
chromatography-isotope ratio mass spectrometry [17] as well as
gas chromatography–mass spectrometry (GC–MS) [18–20]. These
mass spectrometry based techniques have also been employed in
other areas of interest, such as biological pathways [21,22]. Finally,
other techniques for the measurement of N2O include GC coupled
to a thermal conductivity detector (TC) and micro-ionisation
cross section detector (MICS) [23]. The limitations of the described
methods include generally low sensitivity, high detection limits
and the use of internal standards that are not ideal or specific, on
a molecular level, for use with N2O. A lack of internal standard
altogether only allows for external calibration which is not the
best approach for gas analysis taking into account the risk of leaks
during sampling, extraction and analysis [10,24]. Even if other published
GC–MS approach described a better sensitivity, the use of
pre-loading airtight gas syringe should prevent any quantification
problem due to leaks.