Partition Coefficients of Organic Contaminants with Carbohydrates

Abstract

In view of the current lack of reliable partition coefficients for organic compounds with carbohydrates (K ch ), carefully measured values with cellulose and starch, the two major forms of carbohydrates, are provided for a wide range of compounds: short-chain chlorinated hydrocarbons, halogenated benzenes, alkyl benzenes, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, and organochlorine pesticides. To ensure the accuracy of the K ch data, solute concentrations in both water and carbohydrate phases are measured by direct solvent extraction of the samples. For a given compound, the observed partition coefficient with cellulose (K cl ) is virtually the same as that with starch (K st ). This finding expedites the evaluation of organic contamination with different forms of carbohydrates. The presently determined K ch values of 13 PAHs are substantially lower (by 3-66 times) than the literature data; the latter are suspect as they were obtained with (i) presumably impure carbohydrate samples or (ii) indirectly measured equilibrium solute concentrations in carbohydrate and water phases. Although the K ch values are generally considerably lower than the respective K ow (octanol-water) or K lipid (lipid-water), accurate K ch data are duly required to accurately estimate the contamination of carbohydrates by organic compounds because of the abundance of carbohydrates over lipids in crops and plants. To overcome the current lack of reliable K ch data for organic compounds, a close correlation of log K ch with log K ow has been established for predicting the unavailable K ch data for low-polarity compounds.

Dermal uptake of phthalates from clothing: Comparison of model to human participant results

“…Goss applied several computational methods to estimate K cellulose‐water and found that their results correlated well with most measurements reported by Hung et al . Note that DEP and DnBP were excluded from their correlation because their predictions deviated significantly from the Hung et al . results.…”

“…to units of L/kg by dividing their values of by the bulk density of the fabric. For DEP and DnBP, the values of log 10 K cellulose‐air estimated from Hung et al . are lower by 0.3 to 0.8 log units than measured values.…”

“…Computational methods may also allow for estimating partition coefficients for those SVOC‐fabric pairs that have not been investigated experimentally . Goss applied several computational methods to estimate K cellulose‐water and found that their results correlated well with most measurements reported by Hung et al . Note that DEP and DnBP were excluded from their correlation because their predictions deviated significantly from the Hung et al .…”

“…For a wide variety of chemical compounds, Hung et al . measured partition coefficients between carbohydrates (cellulose and starch) and water.…”

Sorption of polycyclic aromatic hydrocarbons (PAHs) by dietary fiber extracted from wheat bran

“…One of the reasons is that the DF had a better sorption capability than the WB, possibly resulting from the extraction process of DF. The hydrophilic residues, such as starch from the WB, have an extremely weak affinity with PAHs [21] and were removed during extraction; thus, the sorption of the PAHs by an unit weight of the DF increased relative to that of the WB.…”