An efficient microfluidic device based on electromembrane extraction for the simultaneous extraction of acidic and basic drugs.

The simultaneous extraction of acidic and basic compounds is considered a great challenge. In this work, an efficient and fast microfluidic device is described for the simultaneous determination of acidic and basic drugs by two electromembrane extraction, offering extraction efficiencies over 98% for all analytes in human urine samples and solving the difficulties encountered to date. The sample is submitted into the device and the collected acceptor phase is directly analyzed by diode array detector and high-pressure liquid chromatography (HPLC).

Electromembrane extraction using deep eutectic solvents as the liquid membrane.

In this work, we investigated for the first time hydrophobic deep eutectic solvents (DES) as supported liquid membrane (SLM) for electromembrane extraction (EME). Camphor, coumarin, DL-menthol, and thymol were used as non-ionic DES components. Different DESs compositions were tested, to study systematically the importance of hydrogen bonding and dispersion/aromatic interactions during mass transfer across the SLM.

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

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.

On-chip electromembrane extraction of acidic drugs.

In the present work, a new supported liquid membrane (SLM) has been developed for on-chip electromembrane extraction of acidic drugs combined with HPLC or CE, providing significantly higher stability than those reported up to date. The target analytes are five widely used non-steroidal anti-inflammatory drugs (NSAIDs): ibuprofen (IBU), diclofenac (DIC), naproxen (NAX), ketoprofen (KTP) and salicylic acid (SAL). Two different microchip devices were used, both consisted basically of two poly(methyl methacrylate) (PMMA) plates with individual channels for acceptor and sample solutions, respectively, and a 25 µm thick porous polypropylene membrane impregnated with the organic solvent in between.

A comprehensive study of a new versatile microchip device based liquid phase microextraction for stopped-flow and double-flow conditions.

A new geometry for a versatile microfluidic-chip device based liquid phase microextraction was developed in order to enhance the preconcentration in microfluidic chips and also to enable double-flow and stopped-flow working modes. The microchip device was combined with a HPLC procedure for the simultaneous determination of two different families as model analytes, which were parabens and non-steroidal anti-inflammatories (NSAIDs): Ethyl 4-hydroxybenzoate (Et-P), Propyl 4-hydroxybenzoate (Pr-P), Butyl 4-hydroxybenzoate (Bu-P), IsoButyl 4-hydroxybenzoate (iBu-P), salycilic acid (SAC), ketoprofen (KET), naproxen (NAX), diclofenac (DIC) and ibuprofen (IBU) in urine samples. The new miniaturized microchip proposed in this work allows not only the possibility of working in double-flow conditions, but also under stagnant conditions (stopped-flow) (SF-μLPME).