Evaluation of long-chain alcohols and fatty acids, in combination with alkanes, as markers in the estimation of the composition of four herbages in mixtures

The objective of the study was to assess if long-chain alcohols (alcohols) and long-chain fatty acids (acids), along with long-chain alkanes, could be useful as markers in estimating the composition of mixtures containing herbages found in the Inner Mongolia typical steppe in China. Four herbage species, Stipa daicalensis , Stipa grandis , Artemisia frigid and Cleistogenes squarrosa , were collected during the growing season to characterize the alcohol and acid profiles of these herbages. Principal component analysis (PCA) was used to examine between-species differences in terms of their patterns of alcohols, acids and alkanes. Results confirmed earlier studies that alcohols and acids with even-numbered carbon chains were predominant and the total concentrations of alcohols or acids were generally higher than those obtained for alkanes. The results of PCA indicated that different marker types provided different discriminatory information. Alcohols and alkanes provided complementary discriminatory information, resulting in the clearest separation between the four species analysed. In choosing which markers to use, the results indicate that using more marker types does not always imply better estimates of the composition of mixtures .