“…The presence of the two other acyclic isoprenoid alkanes was suggested by the enhanced response of the m/z 183 MF (Albaiges, 1980) for the «-C 34 and «-C 35 peaks in GC-MS. From these mass spectral data the acyclic isoprenoid alkanes coeluting with these /z-alkanes are probably 2,6,10,14,17,21,25,29-octamethyl- hentriacontane (IV) and lycopane (2,6,10,14,19,23,27, 31-octamethyldotriacontane, V), since both possess prominent m/z 183 ions Kimble et al, 1974) and appropriate retention times. Trace concentrations (<0.7 ng/g) of two phytene isomers with mass spectra similar to that of phyt-2-ene (3, 7, 11, 15-tetramethylhexadec-2-ene, VI; Urbach and Stark, 1975) were found in Section 491-1-5.…”