Experimental solubility approach to determine PDMS–water partition constants and PDMS activity coefficients

Grant, Sharon, Schacht, Veronika J., Escher, Beate I., Hawke, Darryl W. and Gaus, Caroline (2016) Experimental solubility approach to determine PDMS–water partition constants and PDMS activity coefficients. Environmental Science and Technology, 50 6: 3047-3054. doi:10.1021/acs.est.5b04655


Author Grant, Sharon
Schacht, Veronika J.
Escher, Beate I.
Hawke, Darryl W.
Gaus, Caroline
Title Experimental solubility approach to determine PDMS–water partition constants and PDMS activity coefficients
Journal name Environmental Science and Technology   Check publisher's open access policy
ISSN 0013-936X
1520-5851
Publication date 2016-02-16
Sub-type Article (original research)
DOI 10.1021/acs.est.5b04655
Open Access Status Not Open Access
Volume 50
Issue 6
Start page 3047
End page 3054
Total pages 8
Place of publication Washington DC, United States
Publisher American Chemical Society
Collection year 2017
Language eng
Formatted abstract
Freely dissolved aqueous concentration and chemical activity are important determinants of contaminant transport, fate, and toxic potential. Both parameters are commonly quantified using Solid Phase Micro-Extraction (SPME) based on a sorptive polymer such as polydimethylsiloxane (PDMS). This method requires the PDMS–water partition constants, KPDMSw, or activity coefficient to be known. For superhydrophobic contaminants (log KOW >6), application of existing methods to measure these parameters is challenging, and independent measures to validate KPDMSw values would be beneficial. We developed a simple, rapid method to directly measure PDMS solubilities of solid contaminants, SPDMS(S), which together with literature thermodynamic properties was then used to estimate KPDMSw and activity coefficients in PDMS. PDMS solubility for the test compounds (log KOW 7.2–8.3) ranged over 3 orders of magnitude (4.1–5700 μM), and was dependent on compound class. For polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDDs), solubility-derived KPDMSw increased linearly with hydrophobicity, consistent with trends previously reported for less chlorinated congeners. In contrast, subcooled liquid PDMS solubilities, SPDMS(L), were approximately constant within a compound class. SPDMS(S) and KPDMSw can therefore be predicted for a compound class with reasonable robustness based solely on the class-specific SPDMS(L) and a particular congener’s entropy of fusion, melting point, and aqueous solubility.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
National Research Centre for Environmental Toxicology Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 2 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 2 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Wed, 09 Mar 2016, 10:34:22 EST by Veronika Schacht on behalf of School of Medicine