title: Measurements and predictions of hexadecane/air partition coefficients for 387 environmentally relevant compounds.
abstract: The logarithm of the hexadecane/air partition coefficient L is a common descriptor for non-specific interaction properties of solutes and is used in poly-parameter linear free energy relationships (pp-LFERs) to predict other partition coefficients. However, the L value data set available for complex and multifunctional substances is rather small. This limits the applicability of the pp-LFER equation. Hence, we experimentally determined L values for 387 complex compounds using GC-retention time measurements on a non-polar column (SPB™ Octyl). The target substances include environmentally relevant compounds such as pesticides, flame retardants and hormones. We determined L values that span a large range of 4.28-15.92. In addition to these experimental measurements several prediction tools (connectivity indices, SPARC, ABSOLV, COSMOthermX) for the L value were evaluated. The root mean squared errors (rmse) were 1.55 (connectivity indices), 1.28 (SPARC), 0.99 (ABSOLV) and 0.94 (COSMOthermX). The number of outliers (prediction error>3) was 18 (connectivity indices), 12 (SPARC), 2 (ABSOLV) and 0 (COSMOthermX). Based on these results the best prediction accuracy in this evaluation is reached by ABSOLV and COSMOthermX, whose results are comparable.
authors.affiliation: Helmholtz Centre for Environmental Research UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Stenzel
authors.forename: Satoshi
authors.initials: S
authors.lastname: Endo
authors.forename: Kai-Uwe
authors.initials: KU
authors.lastname: Goss
mesh_terms: D000388:Air / Q000032:analysis*; D000473:Alkanes / Q000032:analysis* / Q000737:chemistry; D005411:Flame Retardants / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006728:Hormones / Q000032:analysis; D016014:Linear Models; D010575:Pesticides / Q000032:analysis; D012984:Software; D013816:Thermodynamics
chemical_list: D000473:Alkanes; D005411:Flame Retardants; D006728:Hormones; D010575:Pesticides; C007932:n-hexadecane