Next Article in Journal
Analysis of the Saltwater Wedge in a Coastal Karst Aquifer with a Double Conduit Network, Numerical Simulations and Sensitivity Analysis
Previous Article in Journal
Evaluation of Various Precipitation Products Using Ground-Based Discharge Observation at the Nujiang River Basin, China
Previous Article in Special Issue
Silica Storage, Fluxes, and Nutrient Stoichiometry in Different Benthic Primary Producer Communities in the Littoral Zone of a Deep Subalpine Lake (Lake Iseo, Italy)
Open AccessCommunication

Analysis of 15N-NO3 Via Anoxic Slurries Coupled to MIMS Analysis: An Application to Estimate Nitrification by Burrowing Macrofauna

1
Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
2
Facultad de Minas, OCEANICOS, Universidad Nacional de Colombia, Medellín 050036, Colombia
3
Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy
4
Marine Science and Technology Center, University of Klaipeda, 92294 Klaipeda, Lithuania
*
Author to whom correspondence should be addressed.
Water 2019, 11(11), 2310; https://doi.org/10.3390/w11112310
Received: 19 September 2019 / Revised: 27 October 2019 / Accepted: 1 November 2019 / Published: 4 November 2019
(This article belongs to the Special Issue The Role of Macrobiota in Aquatic Nutrient Cycling)
The increasing use of the stable isotope 15N-NO3 for the quantification of ecological processes requires analytical approaches able to distinguish between labelled and unlabeled N forms. We present a method coupling anoxic sediment slurries and membrane inlet mass spectrometry to quantify dissolved 15N-NO3 and 14N-NO3. The approach is based on the microbial reduction of 14N-NO3 and 15N-NO3 mixed pool, the determination of the produced 29N2 and 30N2, and the calculation of the original 15N-NO3 and 14N-NO3 concentrations. The reduction is carried out in 12 mL exetainers containing 2 mL of sediment and 10 mL of water, under anoxia. To validate this approach, we prepared multiple standard solutions containing 15N-NO3 alone or in combinations with 14N-NO3, with final concentrations varying from 0.5 to 3000 µM. We recovered nearly 90% of the initial 14N-NO3 or 15N-NO3, over a wide range of concentrations and isotope ratios in the standards. We applied this method to a 15N-NO3 dilution experiment targeting the measurement of nitrification in sediments with and without the burrower Sparganophilus tamesis. The oligochaete did not stimulate nitrification, likely due to limited ventilation and unfavorable conditions for nitrifiers growth. The proposed method is reliable, fast, and could be applied to multiple ecological studies.
Keywords: 15N-NO3, slurry; denitrification; MIMS; nitrification; Sparganophilus tamesis 15N-NO3, slurry; denitrification; MIMS; nitrification; Sparganophilus tamesis
MDPI and ACS Style

Carpintero Moraes, P.; Arroyave Gòmez, D.M.; Vincenzi, F.; Castaldelli, G.; Fano, E.A.; Bartoli, M.; Benelli, S. Analysis of 15N-NO3 Via Anoxic Slurries Coupled to MIMS Analysis: An Application to Estimate Nitrification by Burrowing Macrofauna. Water 2019, 11, 2310.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop