Validation of a spectrophotometric methodology for a rapid iodine analysis in algae and seaweed casts
Iodine plays an important role in human metabolism and its deficiency is particularly harmful in pregnancy and childhood. It remains a major public health concern in many countries, especially in Portugal. The main purpose of this work was to develop a validated spectrophotometric analysis for a fast and reliable iodine quantification in algal samples. Absorbance was determined at 410 nm demonstrating a good linearity (R2 ≈ 1.0) in the range of 0–0.06 mg I/100 g. LOD and LOQ were 1.7 × 10−3 and 5.0 × 10−3 mg I/100 g, respectively. Accuracy was determined using recovery and varied between 101 and 118%. For precision analysis, an intra-day test performance (RSD = 8.7%) and a repeatability assay (RSD = 3.8%) were performed. Matrix effect assessment demonstrated that this had a negligible effect (3.2%) in the iodine quantification. The spectrophotometric method was externally validated, for iodine quantification in algal samples, by INSA certified laboratory. The correlation coefficient between external iodine quantification and our work was R2 ≈ 0.9, showing a good correlation. Applicability was assessed in 25 macroalgae species (5 green, 9 red and 11 brown), 12 seaweed casts, collected in Canary Islands and 1 microalga (Isochrysis galbana) provided by ITC (Instituto Tecnologico de Canarias). ; This work was financially supported by ISOPlexis, University of Madeira; DemoBlueAlgae "Desenvolvimento de metodologias e optimização dos processos de cultivo e processamento de macroalgas para a indústria e economia azul" PROCiência 2020 (M1420-01-0247- FEDER000002); MACBIOBLUE "Proyecto demostrativo y de transferencia tecnológica para ayudar a las empresas a desarrollar nuevos produtos y procesos en el ambito de la Biotecnología Azul de la Macaronesia" (MAC/1.1b/086), program Interreg MAC 2014–2020; ARDITI - Regional Agency for the Development of Research Technology and Innovation (M14-20-09-5369-FSE-000001) Doctorate in Business and UBQ II, Unidade de Bioquímica (UBQ II company). Also, the authors present their acknowledgment to DRCT (Azores Regional Government) for co-financing, the Portuguese National Funds, through FCT-Fundação para a Ciência e a Tecnologia, and as applicable co-financed by the FEDER within the PT2020 Partnership Agreement by funding the cE3c centre (UID/BIA/00329/2013) and to DRCT for funding Azorean Biodiversity Group. ; info:eu-repo/semantics/publishedVersion
