Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Titel (primär) Experimental solubility approach to determine PDMS–water partition constants and PDMS activity coefficients
Autor Grant, S.; Schacht, V.J.; Escher, B.I.; Hawker, D.W.; Gaus, C.;
Journal / Serie Environmental Science & Technology
Erscheinungsjahr 2016
Department ZELLTOX;
Band/Volume 50
Heft 6
Sprache englisch;
POF III (gesamt) T42;
UFZ Querschnittsthemen RU3;
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.
ID 17225
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=17225
Grant, S., Schacht, V.J., Escher, B.I., Hawker, D.W., Gaus, C. (2016):
Experimental solubility approach to determine PDMS–water partition constants and PDMS activity coefficients
Environ. Sci. Technol. 50 (6), 3047 - 3054