"Concentration of octatriaconta-9E,16E,23E-trien-3-one {C38:3 ethyl ketone} per unit volume of the water body [particulate >GF/F phase] by filtration and gas chromatography-mass spectrometry"@en . . "SDN:P01::ET83GCP1" . "The amount of the specified alkenone or alkenoate molecule in particulate material retained by a GF/F filter in a unit volume of water analysed by GC/MS analysis."@en . .