The pseudophase approach to assessing chemical partitioning in air-water-cyclodextrin systems
Gao, H; Blanford, WJ; Birdwell, JE
HERO ID
2551189
Reference Type
Journal Article
Year
2009
Language
English
PMID
| HERO ID | 2551189 |
|---|---|
| In Press | No |
| Year | 2009 |
| Title | The pseudophase approach to assessing chemical partitioning in air-water-cyclodextrin systems |
| Authors | Gao, H; Blanford, WJ; Birdwell, JE |
| Journal | Environmental Science & Technology |
| Volume | 43 |
| Issue | 8 |
| Page Numbers | 2943-2949 |
| Abstract | Henry's Law constants (HLCs) of several common, subsurface hydrophobic organic pollutants (HOPs) including trichloroethylene (TCE), perchloroethylene (PCE) and benzene, toluene, ethylbenzene,and o-xylene (BTEX), were measured using a static headspace phase ratio (SHPR) method over a range of temperatures (35, 45, 55, and 65 degrees C) and experimentally and operationally relevant cyclodextrin (CD) concentrations (0, 10, 20,50,and 100g L(-1)). In aqueous CD solutions, HLC values decrease according to a power law relationship with increasing CD concentration due to an apparent solubility enhancement caused by HOP partitioning to the hydrophobic cavity of CO molecules. The temperature dependence of air-water partitioning under the influence of CD was well described by the van't Hoff equation for all HOPs tested. A three-phase equilibrium model was used to interpret air-water-CD partitioning data, treating CD as a pseudophase. Our results show that HOP CD-water partition coefficients decrease linearly with increasing temperature. CD-water partition coefficients were generally independent of CID concentration, with a few exceptions. Comparison of our results for hydroxypropyl-beta-CD and TCE to those from another study showed several major discrepancies, which were attributed to differences in the experimental methods employed. Our attempt to correlate CD-water partition coefficients with HOP chemical properties indicates that correlations based on individual chemical descriptors (e.g., aqueous solubility, octanol-water partition coefficient, molecular volume or E(T) (30) polarity index) will not be sufficient to obtain accurate estimates of HOP CD-water partition coefficients for other compounds with differing chemical structures. |
| Doi | 10.1021/es803382z |
| Pmid | 19475975 |
| Wosid | WOS:000265172800047 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | ProQuest URL: https://www.proquest.com/docview/754541542?accountid=171501&bdid=64564&_bd=r4h4%2Bh%2Bd4GHK3yaaHNNK3vRPkwE%3D |
| Is Public | Yes |
| Language Text | English |