title: Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.
abstract: The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts.
authors.affiliation: CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal.
authors.forename: Inês C
authors.initials: IC
authors.lastname: Santos
authors.affiliation: CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal; Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto, Portugal. Electronic address: rmesquita@porto.ucp.pt.
authors.forename: Raquel B R
authors.initials: RB
authors.lastname: Mesquita
authors.affiliation: Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto, Portugal.
authors.forename: Adriano A
authors.initials: AA
authors.lastname: Bordalo
authors.affiliation: CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal.
authors.forename: António O S S
authors.initials: AO
authors.lastname: Rangel
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D017022:Flow Injection Analysis / Q000295:instrumentation; D007452:Iodates / Q000032:analysis*; D007454:Iodides / Q000032:analysis*; D007455:Iodine / Q000032:analysis*; D017736:Ion-Selective Electrodes; D057230:Limit of Detection; D012624:Seaweed / Q000737:chemistry*; D013053:Spectrophotometry; D014867:Water / Q000032:analysis*
chemical_list: D007452:Iodates; D007454:Iodides; D014867:Water; D007455:Iodine
keywords: Iodate; Iodide; Iodide selective electrode; Sequential injection; Spectrophotometry; Standard addition methods