Did anyone in this group manage to successfully measure nitrate isotopes (15N and 18O) by converting it to N2O and measuring it in the Picarro N2O analyzer? I found publications on converting nitrate to N2O and then measuring it in an IRMS and also a Los Gatos N2O instrument, but nothing specifically for the Picarro CRSD instrument. The Los Gatos and Picarro instruments are both running on almost the same principle – laser measurments in a cavity – but the Picarro instrument is having a much smaller range of applicable N2O concentrations (300-1000 ppb), so the methods for IRMS and the Los Gatos instruments are not directly transferrable and trying to do so has proven to be very challenging so far.
Hence the question specifically if someone has managed to get any of the methods (Cd-Azide, Titanium Oxide, Denitrifier method) to convert nitrate to N2O working with a Picarro instrument?
Dr. Anja Wunderlich
TU Munich, Faculty of Civil, Geo and Environmental Engineering (Hydrogeology)
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