Possible algal origin of long chain odd n-alkanes in immature sediments as revealed by distributions and carbon isotope ratios

Stable carbon isotope evidence for the microbial origin of C14C18 n-alkanoic acids in soils

“…They were found to be similar for the incubation of distilled water (blank) and glucose. Carbon isotope analyses are described elsewhere (Lichtfouse et al, 1994b). Isotopic compositions are summurized in Table 1 and are expressed in per mil.…”

Molecular, 13C, and 14C evidence for the allochthonous and ancient origin of C16C18 n-alkanes in modern soils

“…relative to the Pee Dee Belemnite standard: δ 13 C = [( 13 C/ 12 C sample -13 C/ 12 C std)/( 13 C/ 12 C std)] x 10 3 , where 13 C/ 12 C std = 0.0112372. The δ 13 C values of maize wax n-alkanes are -19.0‰ (C 25 ), -19.1‰ (C 27 ), -18.4‰ (C 29 ), -20.6‰ (C 31 ) and -22.2‰ (C 33 ) (LICHTFOUSE et al, 1994c). …”

Hydrocarbons as Indicators for Provenance and Thermal History of Organic Matter in Late Cenozoic Sediments from Hole 909C, Fram Strait

“…This indicates the increasing complexity and abundance of the polycyclic nonaromatic hydrocarbons relative to the n-alkanes. The n-alkane distributions are dominated by longchain homologs typical of epicuticular waxes of higher land plants (Eglinton et al, 1962), although long-chain n-alkanes may also derive from n-alkadiene precursors in Botryococcus braunii algae (Lichtfouse et al, 1994). Since there is no other indication of a lacustrine algal contribution to the organic matter in Hole 909C sediments, a higher plant origin of the n-alkanes appears more likely.…”