title: Water solubility of selected C9-C18 alkanes using a slow-stir technique: Comparison to structure - property models.
abstract: Aqueous solubility is a fundamental physical-chemical substance property that strongly influences the distribution, fate and effects of chemicals upon release into the environment. Experimental water solubility was determined for 18 selected C9-C18 normal, branched and cyclic alkanes. A slow-stir technique was applied to obviate emulsion formation, which historically has resulted in significant overestimation of the aqueous solubility of such hydrophobic liquid compounds. Sensitive GC-MS based methods coupled with contemporary sample extraction techniques were employed to enable reproducible analysis of low parts-per billion aqueous concentrations. Water solubility measurements for most of the compounds investigated, are reported for the first time expanding available data for branched and cyclic alkanes. Measured water solubilities spanned four orders of magnitude ranging from 0.3 μg/L to 250 μg/L. Good agreement was observed for selected alkanes tested in this work and reported in earlier literature demonstrating the robustness of the slow-stir water solubility technique. Comparisons of measured alkane water solubilities were also made with those predicted by commonly used quantitative structure-property relationship models (e.g. SPARC, EPIWIN, ACD/Labs). Correlations are also presented between alkane measured water solubilities and molecular size parameters (e.g. molar volume, solvent accessible molar volume) affirming a mechanistic description of empirical aqueous solubility results and prediction previously reported for a more limited set of alkanes.
authors.affiliation: Toxicology & Environmental Sciences Division, ExxonMobil Biomedical Sciences, Inc., 1545 US Highway 22 East, Annandale, NJ, 08801-3059, USA. Electronic address: daniel.j.letinski@exxonmobil.com.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Letinski
authors.affiliation: Toxicology & Environmental Sciences Division, ExxonMobil Biomedical Sciences, Inc., 2777 Springwood Village Parkway, Spring, Texas 77339-1425, USA.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Parkerton
authors.affiliation: Toxicology & Environmental Sciences Division, ExxonMobil Biomedical Sciences, Inc., 1545 US Highway 22 East, Annandale, NJ, 08801-3059, USA.
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Redman
authors.affiliation: Toxicology & Environmental Sciences Division, ExxonMobil Biomedical Sciences, Inc., 1545 US Highway 22 East, Annandale, NJ, 08801-3059, USA.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Connelly
authors.affiliation: Corporate Strategic Research, ExxonMobil Research and Engineering 1545 US Highway 22 East, Annandale, NJ, 08801-3059, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Peterson
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008962:Models, Theoretical; D021281:Quantitative Structure-Activity Relationship; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000473:Alkanes; D012997:Solvents; D014867:Water
keywords: Alkanes; Cycloalkanes; Slow-stir method; Water solubility