A Novel Membrane Inlet Mass Spectrometer Method to Measure 15NH4+ for Isotope-Enrichment Experiments in Aquatic Ecosystems

Yin, Guoyu; Hou, Lijun; Liu, Min; Liu, Zhanfei; Gardner, Wayne S.

doi:10.1021/es501261s

Cited by 151 publications

(113 citation statements)

References 76 publications

(138 reference statements)

Supporting

Mentioning

113

Contrasting

Order By: Relevance

“…The incubations of these sediment‐slurries, designated as final samples, were stopped by addition of HgCl 2 as described for the initial samples. The concentrations of 15 N‐labeled products (including ammonia and organic nitrogen fractions) (Seitzinger & Garber, ) generated during the incubations were determined with a membrane inlet mass spectrometer after the samples were oxidized by hypobromite iodine solution (Yin et al, ). Potential rates of nitrogen fixation were estimated according to the following equation:…”

Section: Methodsmentioning

confidence: 99%

Nitrogen Fixation in the Intertidal Sediments of the Yangtze Estuary: Occurrence and Environmental Implications

et al. 2018

Self Cite

View full text Add to dashboard Cite

Nitrogen fixation is a microbial‐mediated process converting atmospheric dinitrogen gas to biologically available ammonia or other molecules, and it plays an important role in regulating nitrogen budgets in coastal marine ecosystems. In this study, nitrogen fixation in the intertidal sediments of the Yangtze Estuary was investigated using nitrogen isotope tracing technique. The abundance of nitrogen fixation functional gene (nifH) was also quantified. The measured rates of sediment nitrogen fixation ranged from 0.37 to 7.91 nmol N g−1 hr−1, while the abundance of nifH gene varied from 2.28 × 106 to 1.28 × 108 copies g−1 in the study area. The benthic nitrogen fixation was correlated closely to the abundance of nifH gene and was affected significantly by salinity, pH, and availability of sediment organic carbon and ammonium. It is estimated that sediment nitrogen fixation contributed approximately 9.3% of the total terrigenous inorganic nitrogen transported annually into the Yangtze estuarine and coastal environment. This result implies that the occurrence of benthic nitrogen fixation acts as an important internal source of reactive nitrogen and to some extent exacerbates nitrogen pollution in this aquatic ecosystem.

show abstract

Section: Methodsmentioning

confidence: 99%

Nitrogen Fixation in the Intertidal Sediments of the Yangtze Estuary: Occurrence and Environmental Implications

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…Potential rates of DNRA were measured using slurry incubations incorporated with 15 N isotope‐tracing technique [ Yin et al ., ]. Briefly, sediment samples were mixed with site water at a ratio of 1:7 to make homogenized slurries [ Hou et al ., ].…”

Section: Methodsmentioning

confidence: 99%

“…After being incubated for 2 h, 4 h, and 8 h, four of the remaining slurry vials were preserved with HgCl 2 as described above, respectively. The produced 15 NH 4 + during the incubation was quantified using membrane inlet mass spectrometry (HPR‐40, Hiden Analytical, UK) after being oxidized into 29 N 2 and/or 30 N 2 with 0.2 mL hypobromite iodine oxidant [ Yin et al ., ]. Potential rates of DNRA were calculated based on the linear regression of the process‐specific 15 NH 4 + concentrations versus incubation time, according to the following equation:

R = K \times V \times W^{- 1}

…”

Section: Methodsmentioning

confidence: 99%

DNRA in intertidal sediments of the Yangtze Estuary

et al. 2017

Self Cite

View full text Add to dashboard Cite

Dissimilatory nitrate reduction to ammonium (DNRA) plays an important role in regulating the fate of reactive nitrogen in estuarine and coastal ecosystems. In this work, intertidal sediments of the Yangtze Estuary were collected in January and August 2015. Potential rates of DNRA and associated functional gene were investigated with nitrogen isotope‐tracing and molecular techniques. The measured DNRA rates ranged from 0.14 to 5.57 μmol 15N kg−1 h−1 in the intertidal sediments. DNRA rates were tightly related to abundance of nrfA gene (p < 0.001), demonstrating that fermentation reaction may be the dominant pathway of DNRA in the study area. Redundancy analysis (RDA) showed a relationship between DNRA and organic matter and NO2−, suggesting that these substrates stimulated the metabolism of DNRA microorganisms. On the other hand, the correlation between abundances of nrfA gene and Fe2+ and sulfide in the RDA analysis implied that oxidation of both Fe2+ and sulfide can enhance fermentative DNRA by providing extra free energy. DNRA converted approximately 2.29 × 105 t of nitrate to ammonia annually in the sampling area of the Yangtze Estuary, and most of the converted ammonium was retained in the estuarine ecosystem. DNRA may further contribute to eutrophication in the Yangtze Estuary and also in the other hypereutrophic estuaries.

show abstract

“…NH 4 + was then extracted with 2 M KCl from the initial and final sediment slurries [ Lin et al , ]. After extraction, the total NH 4 + (including 14 NH 4 + and 15 NH 4 + ) in extractants was analyzed as described above, while the 15 NH 4 + in extractants was oxidized with hypobromite iodine to N 2 and determined with membrane inlet mass spectrometer [ Yin et al , ].…”

Section: Methodsmentioning

confidence: 99%

Nitrogen mineralization and immobilization in sediments of the East China Sea: Spatiotemporal variations and environmental implications

et al. 2016

Self Cite

View full text Add to dashboard Cite

Nitrogen (N) mineralization and immobilization are important processes of N biogeochemical cycle in marine sediments. This study investigated gross N mineralization (GNM) and NH4+ immobilization (GAI) in the sediments from the East China Sea (ESC), using 15N stable isotope dilution technique. Results show that measured rates of GNM and GAI ranged from 0.04 to 6.1 µg N g−1 d−1 and from undetectable to 9.82 µg N g−1 d−1, respectively. In general, both GNM and GAI rates were significantly greater in summer as compared to winter, and the high rates occurred mainly in the muddy area and increased gradually from the Yangtze Estuary to Zhe‐Min Coastal muddy areas. The GNM and GAI processes were related closely to sediment temperature, pH, ammonium (NH4+), nitrate (NO3−), total organic carbon (TOC), and total nitrogen (TN) contents in the muddy area, while they were associated tightly with sediment temperature, pH, NH4+, TOC, TN, sulfide, and Fe(III) concentrations in the sandy area. In addition, the total mineralized and immobilized N in the East China Sea (ECS) were estimated to be approximately 2.1 × 106 t N yr−1 and 2.7 × 106 t N yr−1, respectively. Overall, these results highlight the importance of N mineralization and immobilization in controlling the N budget in the ECS and improve the understanding of both processes and associated controlling mechanisms in the coastal marine ecosystem.

show abstract

A Novel Membrane Inlet Mass Spectrometer Method to Measure ¹⁵NH₄⁺ for Isotope-Enrichment Experiments in Aquatic Ecosystems

Cited by 151 publications

References 76 publications

Nitrogen Fixation in the Intertidal Sediments of the Yangtze Estuary: Occurrence and Environmental Implications

Nitrogen Fixation in the Intertidal Sediments of the Yangtze Estuary: Occurrence and Environmental Implications

DNRA in intertidal sediments of the Yangtze Estuary

Nitrogen mineralization and immobilization in sediments of the East China Sea: Spatiotemporal variations and environmental implications

Contact Info

Product

Resources

About