Detection of short-chain aldehydes in marine organisms: the diatom Thalassiosira rotula

Short-chain aldehydes are analysed by GC–MS and NMR after their transformation into the corresponding carboxyethylethylidene (CET) derivatives via Wittig reaction. The procedure implies the treatment of the aldehyde with (carbetoxyethylidene)- triphenylphosphorane under very mild conditions. The method is suitable for the detection of short and medium chain aldehydes. CET derivatives are easily prepared and can be utilised for the analysis of raw biological samples. The efficacy of the method has been tested in the identification of biologically active aldehydes in the marine diatom Thalassiosira rotula. At least two compounds, trans,trans-octadienal and 2-trans-4-trans-2,4,7-octatrienal, that have not been revealed in previous papers are unambiguously identified in the microalga.