Direct quantification of inorganic iodine in seawater by mixed-mode liquid chromatography-electrospray ionization-mass spectrometry

Atmospheric iodine plays a relevant role in climate change. Bearing in mind that most of this iodine comes from the oceans, analytical methods capable of determining iodine in a challenging matrix as seawater are necessary. In this work, the first method capable of direct determination of total inor...

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Detalles Bibliográficos
Autores: Hernáiz-Izquierdo, M., Galindo-Iranzo, Plácido, García-Armada, M.P., Saiz-Lopez, A., Gómara, Belén, Quintanilla-López, Jesús Eduardo, Lebrón-Aguilar, Rosa
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/184158
Acceso en línea:http://hdl.handle.net/10261/184158
Access Level:acceso abierto
Palabra clave:Liquid chromatography-electrospray
Seawater
Mixed-mode stationary phase
IodideIodate
ionization-mass spectrometry
Descripción
Sumario:Atmospheric iodine plays a relevant role in climate change. Bearing in mind that most of this iodine comes from the oceans, analytical methods capable of determining iodine in a challenging matrix as seawater are necessary. In this work, the first method capable of direct determination of total inorganic iodine in seawater at subnanomolar level based on mixed-mode liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) without any sample treatment is presented. Analytical characteristics of the developed method were studied in terms of linear range, limits of detection and quantification, precision, trueness, matrix effect, and robustness. The detection limit for iodide was as low as 0.16 nM, injecting 5 μL of seawater without any sample treatment and the working linear range of four orders of magnitude was wide enough to cover the broad concentration range observed in seawater samples. Average values for repeatability and intermediate precision were 4.1% and 8.1%, respectively. The suitability of the method was demonstrated through its application to the analysis of several types of samples, including seawater samples taken at different locations along the Spanish Mediterranean coast and some domestic iodized salts. According to the results obtained, the method developed is rapid, easy to apply and to be automated, avoids sample treatment and requires only few microliters of sample. Furthermore, it has a low detection limit and allows the quantification of inorganic iodine over a wide concentration range.