Fatty acids in zooplankton Nansen Legacy Q4

Study Extent

Sampling

Method steps

1. Fatty acids were analysed at the Alfred Wegener Institute, Bremerhaven, Germany. All samples were freeze-dried for at least 24 h prior to lipid extraction (-45 °C, 0.1 mbar). Zooplankton were homogenized mechanically using a Potter-Elvehjem homogenizer. Total lipids were extracted using a modified procedure from Folch et al. (1957) with dichloromethane/methanol (2:1, v/v). The extracted lipids were cleaned with 0.88 % potassium chloride solution and converted into fatty acid methyl esters (FAMEs) and free fatty alcohols derived from wax esters by transesterification in methanol, containing 3 % concentrated sulfuric acid, at 80 °C for 4 h. After a subsequent hexane extraction, the FAMEs and alcohols were separated split-less via gas chromatography. FAMEs were identified via standard mixtures and total lipid content was quantified with an internal standard (23:0) that was added prior to lipid extraction. Folch, J., Lees, M., and Stanley, G.H.S. (1957). A simple method for the isolation and purification of total lipides from animal tissues. J. Biol. Chem. 226(1), 497-509

1. Calanus glacialis
2. Calanus hyperboreus
3. Calanus finmarchicus
4. Themisto abyssorum
5. Themisto libellula