title: Method for measuring the logarithm of the octanol-water partition coefficient by using short octadecyl-poly(vinyl alcohol) high-performance liquid chromatography columns.
abstract: A simple, quick, versatile and inexpensive HPLC method to estimate the logarithm of the octanol-water partition coefficient (log Pow) employing a methanol-water gradient and a short octadecyl-poly(vinyl alcohol) (ODP) column is described. This method is different from published HPLC-based log Pow methods because it uses retention times from a rapid methanol-water gradient to directly generate log Pow estimates, rather than from a series of isocratic mixtures extrapolated to 100% water. These HPLC log Pow values have good precision and correlate well with traditional shake-flask log Pow values. If necessary, the log Pow determination (including replications) can easily be carried out using only a milligram of sample. By suppressing ionization of acids and bases by the use of a buffer in the aqueous phase, the method can measure the log Pow of neutral organic molecules at any pH between 2 and 13. The method can be used with impure material and is rapid, 7 min per run and 4 min equilibration; it lends itself to and has been utilized for high-throughput hydrophobicity determinations (we have now carried out thousands of HPLC log Pow measurements by this method).
authors.affiliation: BASF, Princeton, NJ 08543-0400, USA. stephendonovan@earthlink.net
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Donovan
authors.forename: Mark C
authors.initials: MC
authors.lastname: Pescatore
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D000442:Octanols / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014867:Water / Q000737:chemistry*
chemical_list: D000442:Octanols; C468554:octadecyl-poly(vinyl alcohol); D014867:Water; D011142:Polyvinyl Alcohol