Impedance model for voltage optimization of parabens extraction in an electromembrane millifluidic device.

Santigosa-Murillo, Elia; Muñoz-Berbel, Xavier; Maspoch, Santiago; Muñoz, María; Ramos-Payán, María

In sample pre-treatment, millifluidic electromembrane platforms have been developed to extract and pre-concentrate target molecules with good clean-up that minimize matrix effects. Optimal operation conditions are normally determined experimentally, repeating the extractions at different conditions and determining the efficiencies by an analytical technique. To shorten and simplify the optimization protocol, millifluidic platforms have been electrically characterized by impedance spectroscopy. The magnitude of the resistance of the electromembrane has been found very predictive of the migration capacity and extraction efficiency of three different parabens on real time. The optimal conditions (4 V of applied potential) (Electromembrane extraction low voltage) have been successfully applied in the extraction of parabens from urine samples, that not only improves the extraction efficiency (100% for all compounds) but also provides a very low current intensity (7 µA), which is very important in electromembrane to minimize electrolysis phenomena. The possibility to optimize one of the most critical and important parameters such as the voltage with a simple electrical model may accelerate the production of application-specific millifluidic electromembrane platforms in a short development time. The results showed that millifluidic electromembrane extraction based low voltage has a future potential as a simple, selective, and time-efficient sample preparation technique allowing a simple battery as power supply.