Distribution of hydrophilic and lipophilic arsenic species within the macroalgae

• Main Author: Sim, Rebecca Jane
• Other Authors: Ásta Heiðrún Pétursdóttir, Raunvísindadeild (HÍ), Faculty of Physical Sciences (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences 2024
• Subjects: Doktorsritgerðir; Efnafræði (námsgrein); Þörungar; Arsen; Iceland
• Online Access: https://hdl.handle.net/20.500.11815/4935

In recent years seaweed has gained popularity as a health food due to its high content of minerals and vitamins. However, seaweeds may also accumulate high levels of potentially toxic elements – in particular arsenic, which may become incorporated into larger biological molecules such as sugars and lipids. It is unclear how these organic arsenic compounds are formed/stored and if they may serve a biological purpose (i.e., detoxification or energy storage). However, toxicological studies into arsenic-containing lipids have demonstrated cytotoxicity comparable to that of arsenite, a known carcinogen, and arsenic-containing sugars are suspected to display toxicity with chronic exposure. This thesis aims to investigate variations in the distribution of arsenic compounds throughout several classes and species of seaweed. Samples of brown, red and green macroalgae were collected from two locations in Iceland across two different months and analysed for several potentially toxic elements as well as hydrophilic arsenic speciation using HPLC-ICP-MS. Brown macroalgae were additionally sectioned into anatomical parts to determine if the distribution of arsenic species differs throughout the thallus. Select samples were chosen for state-of-the-art lipophilic arsenic speciation using HPLC-ICP-MS/ESI-MS/MS and HPLC-qToF-MS. Limited information is available on arsenic speciation in seaweed thus it is hoped that this extensive profiling of several different species will help elucidate how these unusual compounds are formed and stored. The data from this project will also contribute to the necessary information needed for the risk assessment of arsenic species in seaweed for human consumption and may have an impact on future food safety legislations. Þörungar geta tekið upp mikið magn af frumefninu arsen úr sjónum á efnaforminu ólífrænt arsen sem er þekktur krabbameinsvaldur. Í þörungunum greinist arsen einnig á formi fjölbreyttra lífrænna efnasambanda arsens t.d. arsenósykrur og arsenólípíð, en lífrænar arsentegundir hafa ...