Comment on 'Partition Coefficients of Organic Contaminants with Carbohydrates'

摘要

Hung et al. (2) measured carbohydrate-water partition coefficients (K_(ch)) for cellulose (microcrystalline powder from cotton linears) and starch (amylopectin from unmodified waxy com) for 59 organic compounds. These coefficients are highly relevant as sorption to carbohydrates influences the translocation of organic contaminants in vegetated areas. Hung et al. (1) note that available K_(ch), data are highly variable, with measured values for PAHs by Zhang and Zhu (2) and Jonker (3) being 3-66 times higher than Hung et al.'s (i) values. Three explanations are possible: (1) heterogeneity of carbohydrates present (e.g., mixed carbohydrate extract in (2)), (2) residual impurities (e.g., lignin or lipids), and (3) variable crystallinity. Hung et al. (2) mainly discuss the second explanation. However, we hypothesize the third explanation may also be partly responsible.