Relationship between Olive Oil:Air, Saline:Air, and Rat Brain:Air Partition Coefficients of Organic Solvents In Vitro

• Published in: Journal of Toxicology and Environmental Health, Part A Vol. 66; no. 20; pp. 1985 - 1998
• Main Authors: Meulenberg, Cécil, Wijnker, Anna, Vijverberg, Henk
• Format: Journal Article
• Language: English
• Published: London Informa UK Ltd 24.10.2003; Taylor and Francis
• Subjects: Air; Animals; Biological and medical sciences; Brain - drug effects; Culture Techniques; Drug Interactions; General aspects. Methods; Male; Medical sciences; Olive Oil; Plant Oils - pharmacology; Rats; Rats, Wistar; Regression Analysis; Sodium Chloride - pharmacology; Solvents - chemistry; Solvents - pharmacology; Toxicology; Gas liquid interface; Rat; Homogenate; Partition coefficient; Encephalon; Chlorocarbon; Hydrocarbon; Rodentia; Prediction; Volatile organic compound; Air; Regression analysis; Olive oil; Ketone; In vitro; Regression coefficient; Pollutant; Organic solvent; Vertebrata; Mammalia; Animal; Alkanone; Property structure relationship; Saline solution; Physicochemical properties
• ISSN: 1528-7394; 1087-2620; 2381-3504
• DOI: 10.1080/713853954

Partition coefficients of 28 volatile organic solvents (13 alkylbenzenes, 10 chlorinated hydrocarbons, and 5 ketones) in olive oil, saline, and rat brain tissue homogenates were measured by equilibration in a closed vial and subsequent gas-chromatographic analysis of headspace air. The values of oil and saline partition coefficients correlate well with previously reported data. Brain partition coefficients were fit to a bilinear equation of the form P brain:air = f o P oil:air + f s P saline:air + c. The regression coefficients accurately predicted previously reported rat brain partition coefficients of 19 solvents with distinct physicochemical properties within a factor of 2.5. The combined data set of presently determined and previously reported brain partition coefficients (n = 46) yields tissue-specific regression coefficients for solvent partitioning in rat brain of 0.028 for f O' , 0.845 for f S' , and 0.90 for the intercept, with coefficients of variation amounting to 11%, 4%, and 463%, respectively. The generalized empirical relationship predicts the brain partition coefficients within a factor of 2.5 accurately for 95% of the compounds. The ratios of rat brain concentrations calculated from predicted and measured P brain:air and P blood:air values were within a factor of 4 for 95% of the compounds. It was concluded that the enlargement of the empirical data set leads to more reliable predictions of rat brain partition coefficients, particularly for the lipophilic volatile organic compounds.