Continuous Counter-Current Multistage Microextraction in a Novel Tube-In-Tube Microextractor

Abstract

Counter-current operation has been widely applied to enhance the extraction efficiency for systems with low distribution coefficients, which was hindered in microextraction because viscous force and surface tension dominate over gravity and inertial force. In this study, a novel design of a tube-in-tube microextractor relying on a poly tetra fluoroethylene membrane to construct a stable interface was proposed to conduct continuous counter-current extraction. Extraction kinetics for two systems with different distribution coefficients, membranes with different pore radii, and three flow rate ratios were measured as a function of residence time. For the system that toluene was used to extract 0.06 wt % phenol in water, 4.1 stages of extraction efficiency were achieved at a residence time of 9.8 min. A challenging case study (50 wt % acetone−water−toluene) was subsequently conducted to prove the high applicability for emulsion systems of this special microextractor. Lastly, a mathematical model was established and the predicted results of three flow rate ratios are in good agreement with experimental results.

Advancements in solvent microextraction: Recent developments and diverse applications in the modern era

“…Analytes partition between the sample solution and the flowing organic solvent, leading to their extraction and preconcentration. CFME carries various drawbacks that necessitate careful consideration [63]. The ongoing nature of the extraction process introduces the risk of contaminant carryover from one sample to the next, impacting the precision and reproducibility of the method.…”