Rapid determination of octanol-water partition coefficient using vortex-assisted liquid-liquid microextraction

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Accurate determination of octanol-water partitioning coefficients (Kow) is crucial for understanding chemical behavior in biological and environmental systems.
• Traditional Kow measurement methods can be time-consuming and require significant solvent volumes.

Purpose of the Study:

• To develop a rapid, efficient, and cost-effective method for determining Kow using vortex-assisted liquid-liquid microextraction (VALLME) coupled with high-performance liquid chromatography (HPLC).
• To validate the VALLME-HPLC method for logKow determination across a range of model compounds.

Main Methods:

• Vortex-assisted liquid-liquid microextraction (VALLME) employing vortex agitation to create microemulsions for enhanced interfacial contact.
• Utilizing centrifugation for phase separation and collecting the octanolic microdrop for analysis.
• High-performance liquid chromatography (HPLC) for the quantitative analysis of model compounds in the octanolic phase.

Main Results:

• VALLME achieved equilibrium in just 2 minutes, significantly reducing analysis time.
• The method demonstrated high reliability, producing logKow values consistent with published data.
• The determined logKow values for six model compounds (logKow range ~0.5 to 3.5) exhibited acceptable uncertainty.

Conclusions:

• VALLME-HPLC is a rapid, reliable, simple, and cost-effective technique for Kow determination.
• The method's minimal solvent consumption and speed make it an attractive alternative to conventional approaches.
• This technique offers a valuable tool for researchers requiring efficient and accurate measurement of lipophilicity.