The analysis of vitamin E in phyto- and zooplankton samples
(English)Manuscript (preprint) (Other academic)
Vitamin E (a-tocopherol in particular) is one of the major and most potent lipid-soluble antioxidants in vivo. It is produced by autotrophs and is essential in the diet of heterotrophs. In the last decades deficiencies of essential substances such as astaxanthin and vitamin B1 (thiamine) were discovered in aquatic top predators and underlying causes seem to be food-web related. In the case of vitamin E, there is a lack of studies on the mechanisms of production and transport in aquatic food webs, which is partly related to complicated extraction procedures and high detection limits. This paper presents an improved method for the extraction and detection of a-, g- and d-tocopherol in low-biomass plankton samples. The method uses N,N-dimethylformamide (DMF) and n-hexane as extraction solvents with sodium dodecyl sulphate (SDS) as additive. This improves extraction yield and simplifies the extraction procedure because elaborate homogenization and saponification steps are unnecessary and extraction time is decreased to 1 min. Quantification of vitamin E is performed with high performance liquid chromatography (HPLC) using electrochemical detection (ECD). Detection limits of the new method are 18.5, 16.3 and 8.0 pg injected and 0.74, 0.65 and 0.32 ng mL-1 extract for a-, g- and d-tocopherol, respectively. Altogether, this is a reliable, fast and sensitive method which will allow more detailed investigations of vitamin E dynamics in aquatic food webs.
alpha-tocopherol, zooplankton, phytoplankton, HPLC, ECD
Research subject Analytical Chemistry; Biology
IdentifiersURN: urn:nbn:se:uu:diva-130137OAI: oai:DiVA.org:uu-130137DiVA: diva2:346640