Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/acs.jced.6b00196
Title (Primary) Evaluating the salting-out effect on the organic carbon/water partition ratios (KOC and KDOC) of linear and cyclic volatile methylsiloxanes: Measurements and polyparameter linear free energy relationships
Author Panagopoulos, D.; Kierkegaard, A.; Jahnke, A. ORCID logo ; MacLeod, M.
Source Titel Journal of Chemical and Engineering Data
Year 2016
Department ZELLTOX
Volume 61
Issue 9
Page From 3098
Page To 3108
Language englisch
UFZ wide themes RU2;
Abstract Dissolved inorganic salts influence the partitioning of organic chemicals between water and sorbents. We present new measurements of the salting-out constants (Ks) for partition ratios between water and organic carbon (KOC) and between water and dissolved organic carbon (KDOC) of three cyclic volatile methylsiloxanes (cVMS), two linear volatile methylsiloxanes (lVMS), three polychlorinated biphenyls (PCBs), and α-hexachlorocyclohexane (α-HCH). Ks, KOC, and KDOC were derived from volatilization rates of the chemicals from mixtures of water and organic carbon with varying concentrations of sodium chloride in a purge-and-trap system. KOC and KDOC values at different salinities were determined by fitting their values to reproduce observed volatilization rates using a fugacity-based multimedia model and assuming first-order kinetics for volatilization. The Ks values of cVMS and lVMS ranged from 0.16–0.76. The log KOC of cVMS and lVMS in fresh water interpolated from our measurements ranged from 5.20 to 7.36 and the log KDOC values from 5.04 to 6.72. Polyparameter linear free energy relationships (PP-LFERs) trained with data sets without measurements for siloxanes failed to accurately describe the log KOC and log KDOC of cVMS and lVMS. Including our measurements for cVMS and lVMS substantially improved the fit. PP-LFERs trained with data for Ks from solubility measurements do not describe our new measurements well regardless of whether or not they are included in the training set, which may reflect differences in the salting-out effect on partitioning to organic carbon versus on solubility.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=18214
Panagopoulos, D., Kierkegaard, A., Jahnke, A., MacLeod, M. (2016):
Evaluating the salting-out effect on the organic carbon/water partition ratios (KOC and KDOC) of linear and cyclic volatile methylsiloxanes: Measurements and polyparameter linear free energy relationships
J. Chem. Eng. Data 61 (9), 3098 - 3108 10.1021/acs.jced.6b00196