Study of enrichment factors for six β-blockers in aliphatic alcohols by hollow-fiber liquid-phase microextraction

The selectivity of a suitable organic solvent is key for extraction in liquid-phase microextraction experiments. Nevertheless, the screening process remains a daunting task. Our research aimed to study the relationship between extraction efficiency and extraction solvents, analytes, and finally select the appropriate extraction solvent. In the present article, beta-blockers and six extraction solvents were chosen as the models and hollow-fiber liquidphase microextraction was conducted. The relationship was built by statistical analysis on the data. Factors affecting extraction efficiency including the logarithms of the octanol/water partition coefficient (logP(o/w)) of analytes, acid dissociation constants, the logarithms of the octanol/water partition coefficient of solvents and pH of the sample solution were investigated. The results showed that a low water solubility of extraction solvent is the foundation to ensure higher extraction efficiency. Moreover, when Delta logP(o/w) > 0, a higher extraction efficiency is observed at lower Delta logP(o/w), on the contrary, when Delta logP(o/w) < 0, extraction efficiency is higher as the absolute value of Delta logP(o/w) becomes greater. Finally, the relationship between enrichment factor and extraction solvents, analytes was established and a helpful guidance was provided for the selection of an optimal solvent to obtain the best extraction efficiency by liquid-phase microextraction.