title: Technical updates to the bacterial method for nitrate isotopic analyses.
abstract: The bacterial conversion of aqueous nitrate (NO(3)(-)) to nitrous oxide (N(2)O) for isotopic analysis has found widespread use since its introduction (Sigman, D. M.; Casciotti, K. L.; Andreani, M.; Galanter, M.; Böhlke, J. K. Anal. Chem.2001, 73, 4145-4153; Casciotti, K. L.; Sigman, D. M.; Galanter Hastings, M.; Böhlke, J. K.; Hilkert, A. Anal. Chem.2002, 74, 4905-4912). The bacterial strain Pseudomonas aureofaciens (ATTC no. 13985) was shown to convert NO(3)(-) to N(2)O while retaining both N and O isotopic signatures, and automation of the isotopic analysis of N(2)O greatly increased the throughput of the method (Casciotti, K. L.; Sigman, D. M.; Galanter Hastings, M.; Böhlke, J. K.; Hilkert, A. Anal. Chem.2002, 74, 4905-4912). Continued development of the denitrifier method has led to increased precision and throughput of NO(3)(-) isotopic analysis. Presented here are several recent procedural modifications and the demonstration of their effectiveness.
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: McIlvin
authors.forename: Karen L
authors.initials: KL
authors.lastname: Casciotti
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D007554:Isotopes / Q000032:analysis*; D009566:Nitrates / Q000032:analysis* / Q000378:metabolism
chemical_list: D007554:Isotopes; D009566:Nitrates