Kai Uwe Goss

..Here, the correct value is estimated to be close to -0.5 based on analogy considerations and molecular modeling. Calculated pKa values for other highly fluorinated carboxylic acids are also presented...

..Our experimental results, however, indicate that this situation does not occur, as the H-bond-interaction behavior of bifunctional molecules in humic matter and on quartz was the same as it was in various solvent systems...

..The present evaluation is limited to chemicals with a rather simple structure. Further evaluation with complex chemicals that possess multiple functionalities is still warranted...

..These pp-LFER equations provide for the first time a tool that allows including the variability of the sorption properties of NOM in environmental fate models...

..In contrast, other empirical models that are also based on the molecular structure of the sorbate have an application domain that is limited by their calibration data set that is often unknown to the user...

....

....

....

..Based on this and earlier experiences we conclude that COSMOtherm may be a better tool for screening large sets of chemicals for which no experimental data on their partitioning yet exist...

..It should therefore prove highly useful in further investigating how different acidic functional groups affect anion sorption to SOM...

..These results imply that risk assessment models for organic bases should take ion-exchange processes into account when estimating soil sorption coefficients and bioavailability...

....

..Based on these results the best prediction accuracy in this evaluation is reached by ABSOLV and COSMOthermX, whose results are comparable...

..g., kidneys, liver) instead of fat tissue can be the primary phase for accumulation...

..The trends in K(ip) data further support findings that the sorption behavior of ambient aerosol samples is different from raw mineral surfaces and soot...

..Based on our experimental data, we present a pp-LFER-model for humic acid/air and humic acid/water partitioning at any ambient temperatures...

..Sorption varied between different types of esters and prediction with LFERs was less accurate than for the ethers...

..Hence, the substance descriptors determined herein should also be helpful in revisiting the validity of existing LSERs for complex, polar compounds...

..These findings expand the domain of chemicals for which POM can be used as an EPS sampler, and demonstrate that POM is as suitable a passive sampler for many polar organic compounds as it is for hydrophobic organic compounds...

..A simple cavity model for partitioning is shown to give good results for fluorinated compounds if the nonspecific interactions are correctly parametrized...

..This model allows us to estimate partition coefficients at desired temperatures that occur under typical ambient conditions...

..We found that the partitioning to muscle protein is typically weaker than that to lipids, but that the protein partitioning of an H-bond donor compound can be as strong as the storage lipid partitioning...

..This study also investigated the influence of temperature on partitioning to WIOM, and found thatthe temperature dependence of Kip values can be reasonably predicted using the pure compound's enthalpy of vaporization...

..In combination with physiologically based pharmacokinetic modelling this improvement in the estimation of milk/water partitioning coefficients may allow a better risk assessment for a wide range of neutral organic chemicals...

..The least accurate predictions occurred with ClogP for the fluorotelomer alcohols, where the estimated values were off by 2 to almost 5 orders of magnitude...

....

..639 (+/- 0.037) log K(i hexadecane/air) + 3.38 (+/- 0.17) sigmabetai + 3.53 (+/- 0.25) sigmaalphai - 6.85. The sorption coefficients measured could be described well with the compound parameters used (subscript i), with an R2 = 0.90...

..Overall, the pp-LFER approach is recommended over other current methods for the purpose of Koc estimation and especially for polar chemicals...

....

..On road tunnel aerosols, both adsorption to EC and absorption in organic matter (OM) governed the observed sorption and the data could not be further evaluated in terms of a specific sorption mechanism...

..The data further revealed that neither EC nor OM was fully available for sorption. The latter leads to the hypothesis that aerosol OM in urban samples has characteristics comparable to those of glassy polymers...

..In the environment one will quite often encounter a situation where water and air do not have the same temperatures. This situation is shortly discussed in the appendix...

..These data provide important insights into the variability of sorption properties of natural, inorganic surfaces as a function of relative humidity...