A Method for Accurate Quantification of <sup>15</sup>N-Enriched Nitric Oxide with Membrane Inlet Mass Spectrometer
Nitric oxide (NO), a key nitrogen cycle intermediate, is an important atmospheric pollutant. However, a reliable method for the accurate determination of NO remains scarce. Here, we report a novel isotopic approach employing acidified potassium iodide (KI) to reduce <sup>15</sup>NO<sub>2</sub><sup>-</sup> to <sup>15</sup>NO, which is then quantified via a membrane inlet mass spectrometer (MIMS). The effects of the reducing agent concentration, settling time, light intensity, salinity, and <sup>15</sup>NO<sub>3</sub><sup>-</sup> concentration on KI reduction were systematically assessed. Under optimized conditions, standard calibration curves demonstrated excellent linearity (R<sup>2</sup> = 0.996) for <sup>15</sup>NO quantification over a range of 0.1 to 200 μmol L<sup>-1</sup>, with a detection limit of 0.1 μmol L<sup>-1</sup>. This method provides accurate (relative error: 4.39%), precise (relative standard deviation: 3.12%), and cost-effective <sup>15</sup>NO analysis for understanding the biogeochemical process of NO dynamics in the environment.
Authors
- Yiguo Hong (ORCID: https://orcid.org/0000-0002-6255-4100)
- Jiapeng Wu (ORCID: https://orcid.org/0000-0003-4633-6530)
- Xiaoyi Li (ORCID: https://orcid.org/0000-0001-5082-6757)
- Yuexi Ma
Institutions
- Bay Institute (US)
- Guangzhou University (CN)
Publication Details
- Journal
- Analytical Chemistry
- Published
- 2025-08-11
- DOI
- https://doi.org/10.1021/acs.analchem.5c03717
- Citations
- 1
- Primary Topic
- Marine and coastal ecosystems
- Type
- article
- Field-Weighted Citation Impact
- 1.79
Funders
- National Natural Science Foundation of China
- Bureau of Education of Guangzhou Municipality
- Guangzhou University
- Guangzhou Science and Technology Program key projects
- Basic and Applied Basic Research Foundation of Guangdong Province