{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T01:59:37Z","timestamp":1768442377806,"version":"3.49.0"},"reference-count":27,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2022,3,23]],"date-time":"2022-03-23T00:00:00Z","timestamp":1647993600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["POCI-01-0145-FEDER-031522"],"award-info":[{"award-number":["POCI-01-0145-FEDER-031522"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002924","name":"FEDER","doi-asserted-by":"publisher","award":["POCI-01-0145-FEDER-031522"],"award-info":[{"award-number":["POCI-01-0145-FEDER-031522"]}],"id":[{"id":"10.13039\/501100002924","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>A flow-based method for the spectrophotometric determination of chromium (VI) in recreational waters with different salinities was developed. Chromium can occur in the environment in different oxidation states with different related physiological properties. With regard to chromium, the speciation is particularly important, as the hexavalent chromium is considered to be carcinogenic. To achieve that purpose, the use of the diphenylcarbazide (DPC) selective colored reaction with the hexavalent chromium was the chosen strategy. The main objective was to develop a direct and simple spectrophotometric method that could cope with the analysis of different types of environmental waters, within different salinity ranges (fresh to marine waters). The potential interference of metal ions, that can usually be present in environmental waters, was assessed and no significant interferences were observed (&lt;10%). For a complete Cr(VI) determination (three replicas) cycle, the corresponding reagents consumption was 75 \u00b5g of DPC, 9 mg of ethanol and 54 mg of sulfuric acid. Each cycle takes about 5 min, including the system clean-up. The limit of detection was 6.9 and 12.2 \u00b5g L\u22121 for waters with low and high salt content, respectively. The method was applied for the quantification of chromium (VI) in both fresh and marine water, and the results were in agreement with the reference procedure.<\/jats:p>","DOI":"10.3390\/molecules27072073","type":"journal-article","created":{"date-parts":[[2022,3,23]],"date-time":"2022-03-23T22:08:06Z","timestamp":1648073286000},"page":"2073","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["A Robust Flow-Based System for the Spectrophotometric Determination of Cr(VI) in Recreational Waters"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9657-5869","authenticated-orcid":false,"given":"T\u00e2nia C. F.","family":"Ribas","sequence":"first","affiliation":[{"name":"CBQF\u2014Centro de Biotecnologia e Qu\u00edmica Fina\u2014Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7745-1860","authenticated-orcid":false,"given":"Raquel B. R.","family":"Mesquita","sequence":"additional","affiliation":[{"name":"CBQF\u2014Centro de Biotecnologia e Qu\u00edmica Fina\u2014Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0732-1571","authenticated-orcid":false,"given":"Ana","family":"Machado","sequence":"additional","affiliation":[{"name":"ICBAS\u2014Instituto de Ci\u00eancias Biom\u00e9dicas Abel Salazar, Universidade do Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal"},{"name":"CIIMAR\u2014UP, Interdisciplinary Centre of Marine and Environmental Research of the University of Porto, Novo Edif\u00edcio do Terminal de Cruzeiros do Porto de Leix\u00f5es, Avenida General Norton de Matos, S\/N, 4450-208 Matosinhos, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9650-303X","authenticated-orcid":false,"given":"Joana L. A.","family":"Miranda","sequence":"additional","affiliation":[{"name":"CBQF\u2014Centro de Biotecnologia e Qu\u00edmica Fina\u2014Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal"}]},{"given":"Graham","family":"Marshall","sequence":"additional","affiliation":[{"name":"Global FIA, Fox Island, WA 98333, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9637-6541","authenticated-orcid":false,"given":"Adriano","family":"Bordalo","sequence":"additional","affiliation":[{"name":"ICBAS\u2014Instituto de Ci\u00eancias Biom\u00e9dicas Abel Salazar, Universidade do Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal"},{"name":"CIIMAR\u2014UP, Interdisciplinary Centre of Marine and Environmental Research of the University of Porto, Novo Edif\u00edcio do Terminal de Cruzeiros do Porto de Leix\u00f5es, Avenida General Norton de Matos, S\/N, 4450-208 Matosinhos, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6486-8947","authenticated-orcid":false,"given":"Ant\u00f3nio O. S. S.","family":"Rangel","sequence":"additional","affiliation":[{"name":"CBQF\u2014Centro de Biotecnologia e Qu\u00edmica Fina\u2014Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kolev, S.D., and McKelvie, I.D. (2008). Advances in Flow Injection Analysis and Related Techniques, Elsevier. [1st ed.].","DOI":"10.1016\/S0166-526X(08)00604-1"},{"key":"ref_2","unstructured":"Buffle, J., and Horvai, G. (2000). In-Situ Monitoring of Aquatic Systems: Chemical Analysis and Speciation, Wiley."},{"key":"ref_3","unstructured":"Wilbur, S., Abadin, H., Fay, M., Yu, D., Tencza, B., Ingerman, L., Klotzbach, J., and James, S. (2021, November 03). 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