an important property that has been extensively studied in quantitative structure activityrelationship (qsar) is the chromatographic retention index. qsar study is suggested for theprediction of retention index of alkanes and alkenes compounds. modeling of the retention indexof alkanes and alkenes compounds as a function of molecular structures was established bydifferent chemometrics methods. ...

Lacustrine sediments have the potential to preserve paleoenvironmental proxies such as terrestrial plant waxes at high temporal resolution. The fidelity of wax records, however, can be up several thousand years older than corresponding sediment, based on compound-specific radiocarbon (14C) analysis. Unfortunately, factors controlling 14C age offsets between and are not well understood. aims thi...

This study sought to characterize hydrogen isotopic fractionation during biosynthesis of leaf wax nalkanes in succulent plants capable of crassulacean acid metabolism (CAM). The metabolic and physiological features of CAM represent crucial strategies for survival in hot and dry climates and have been hypothesized to impact hydrogen isotope fractionation. We measured the stable carbon and hydrog...

The effect of n-alkane faecal recovery on the accuracy of diet composition estimates, when increasing the number of diet components, was studied. Seven dietary treatments, composed of different proportions of herbaceous (Lolium perenne and Trifolium repens) and woody species (Erica umbellata, Erica cinerea, Calluna vulgaris, Erica arborea and Ulex gallii) were offered to 28 goats housed in meta...

The crossover to Rouse-like behavior for the self-diffusion constant D, the viscosity η, and the equilibrium structural statistics of n-alkanes (6 ≤ n ≤ 66) is studied numerically. For small n the chains are non-Gaussian and the mean squared end-to-end distance 〈R2〉 is greater than 6〈R2 G〉, where 〈R2 G〉 is the mean squared radius of gyration. As n increases, 〈R2〉/〈R2 G〉 → 6(1 + a/n), where a de...