Determination of Infinite Dilution Activity Coefficients and 1-Octanol/Water Partition Coefficients of Volatile Organic Pollutants

Abstract

The characterization of pollutants is of growing interest as concerns about the environment increase. One parameter useful in predicting the fate of a chemical in the environment, the infinite dilution activity coefficient, has been determined here for several EPA priority pollutants in 1-octanol at 25 °C using a relative gas-liquid chromatographic measurement technique. A simple correlation has been developed relating the limiting activity coefficients of a species in pure water and in pure 1-octanol to its octanol/water partition coefficient.Agreement between the experimental results and published values is very good. The method developed here of computing the octanol/water partition coefficient from gas chromatographic measurements of its infinite dilution activity coefficients is an improvement over traditional partition coefficient determination methods in that it is easier and quicker, without a loss of accuracy. Furthermore, we show that this method is applicable to chemicals covering a large range of hydrophobicities (1.0 < log K0" < 5.0).

Estrogenic activity of lignin-derivable alternatives to bisphenol A assessed via molecular docking simulations

“…[82][83][84][85] More positive log P values are associated with greater hydrophobicity, and more negative log P values are suggestive of stronger hydrophilicity. [86][87][88][89] It is expected that the more hydrophobic a bisphenol, the greater the probability that it will interact with ERa. 84,90 Therefore, the log P values of all the bisphenols and their respective isomers were calculated using http:// chemicalize.org by ChemAxon 79 and are listed in Table S3.…”

Identifying time-dependent changes in the morphology of an individual aerosol particle from its light scattering pattern

“…After about 8 seconds, even though the water content is clearly still not at equilibrium with the gas phase, the core-shell morphology is no longer detectable ( Figure 6A), suggesting that the droplet is either homogenous, or the shell is too thick to lead to detectable irregularities in the light scatter, or possibly forming an engulfed structure (Reid et al 2011). For example, in a 50:50 by volume mixture of octanol and water, while the water-rich phase is nearly pure (99.99% water), the octanol-rich layer is 20.7 mol% (3% by volume) water (Tse and Sandler 1994). The specific values for dodecanol is similar (3% by weight) (Stephenson and Stuart 1986).…”

Development and Demonstration of an Explicit Lumped-Parameter Biofilter Model and Design Equation Incorporating Monod Kinetics

“…A third method for estimating a Henry's coefficient is to use a published VOC-water infinite dilution, liquidphase activity coefficient [17][18][19][20][21] (γ ∞ ) at its measured solution temperature (T 1 ), but using the pure component vapor pressure at the desired temperature (T 2 ) (3)…”