Rich in micronutrients and considered to contain high iodine levels, seaweeds have multiple applications
as food/supplements and nutraceuticals with potential health implications. Here, we describe the
development and validation of a new analytical method to quantify iodine as iodide (I) using an isocratic
HPLC system with UV detection; algal iodine was converted to I via dry alkaline incineration. The
method was successfully applied to 19 macroalgal species from three taxonomic groups and five
commercially available seaweed food products. Fesh kelps contained highest levels, reaching >1.0% per
dry weight (DW), but concentrations differed amongst thallus parts. In addition to kelps, other brown
(Fucales: 0.05% DW) and some red species (0.05% DW) can also serve as a rich source of iodine; lowest
iodine concentrations were detected in green macroalgae (0.005% DW), implying that quantities recommended
for seaweed consumption may require species-specific re-evaluation to reach adequate daily
intake levels.
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