GEOC 18 |
| We describe an easy and robust method for intromolecular high precision N position specific isotope analysis (PSIA) in Amino Acids (AA) at natural abundance level. Amino-N in AAs is selectively oxidized to NO2- by alkaline hypochlorite with KBr as the catalyst. After 30min reaction in 50°C waterbath, NaAsO2 is added to scavenge excessive hypochlorite. The produced NO2- is then reduced to N2O by azide and analyzed on an isotope ratio mass spectrometer following published procedures. The highly specific oxidizing mechanism largely targets α-amino-N, while the heterocyclic N as well as amino sugar N are left untouched. This method also performs well in complex matrices, such as the hydrolysis of organic poor sediments. Average precision for replicate analysis is STDEV (δ15N) =0.3‰. |
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Modern Calibrations and Terrestrial Applications of Stable Isotope Paleo Proxies
1:30 PM-5:10 PM, Sunday, August 19, 2007 Boston Park Plaza -- St. James Rm, Oral
Sci-Mix
Division of Geochemistry |