Rapid determination of octanol-water partition coefficient using vortex-assisted liquid-liquid microextraction.
Vortex-assisted liquid-liquid microextraction (VALLME) coupled with high-performance liquid chromatography (HPLC) is proposed here for the rapid determination of octanol-water partitioning coefficients (Kow). VALLME uses vortex agitation, a mild emulsification procedure, to disperse microvolumes of octanol in the aqueous phase thus increasing the interfacial contact area and ensuring faster partitioning rates. With VALLME, 2min were enough to achieve equilibrium conditions between the octanolic and aqueous phases. Upon equilibration, separation was achieved using centrifugation and the octanolic microdrop was collected and analyzed in a HPLC system. Six model compounds with logKow values ranging between ∼0.5 and 3.5 were used during the present investigations. The proposed method produced logKow values that were consistent with previously published values and the recorded uncertainty was well within the acceptable log unit range. Overall, the key features of the proposed Kow determination procedure comprised speed, reliability, simplicity, low cost and minimal solvent consumption.
Departamento de Química Analítica, Nutrición y Bromatología e Instituto Universitario de Materiales, Facultad de Ciencias, Universidad de Alicante, P.O. Box 99, E-03080 Alicante, Spain.
Iván P
IP
Román
Laboratory of Aquatic Chemistry, School of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania, Greece.
Anna
A
Mastromichali
Laboratory of Aquatic Chemistry, School of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania, Greece.
Konstantina
K
Tyrovola
Departamento de Química Analítica, Nutrición y Bromatología e Instituto Universitario de Materiales, Facultad de Ciencias, Universidad de Alicante, P.O. Box 99, E-03080 Alicante, Spain.
Antonio
A
Canals
Laboratory of Aquatic Chemistry, School of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania, Greece. Electronic address: elia@enveng.tuc.gr.
Elefteria
E
Psillakis
D002733:Chlorophenols / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004006:Dichlorvos / Q000032:analysis; D004655:Emulsions; D006873:Hydroquinones / Q000032:analysis; D059627:Liquid Phase Microextraction / Q000379:methods*; D009281:Naphthalenes / Q000032:analysis; D000442:Octanols / Q000737:chemistry*; D015203:Reproducibility of Results; D012839:Simazine / Q000032:analysis; D012997:Solvents; D014867:Water / Q000737:chemistry*
D002733:Chlorophenols; D004655:Emulsions; D006873:Hydroquinones; D009281:Naphthalenes; D000442:Octanols; D012997:Solvents; D014867:Water; C031721:naphthalene; D004006:Dichlorvos; C032729:2,6-dichlorophenol; C004762:2,4-dichlorophenol; D012839:Simazine; C031927:hydroquinone
Liquid–liquid microextraction; Octanol–water partition coefficient; Organic compounds; Vortex agitation