Development of carbon-nanotube-assisted electromembrane extraction in the two-phase mode combined with GC for the determination of basic drugs

Abstract

In this work, carbon-nanotube-assisted electromembrane extraction in the two-phase mode combined with GC was developed for the preconcentration and determination of basic drugs in body fluids. The multiwalled carbon nanotubes dispersed in organic solvent are held in the pores of the porous fiber wall by capillary forces and sonification. The membrane with immobilized carbon nanotubes acts as a sorbent and provides an additional pathway for analyte transport. This study demonstrates that the immobilization of carbon nanotubes in the supported liquid membrane is an excellent approach to enhance the performance of the extraction. Optimization of the variables affecting this method was carried out in order to achieve the best extraction efficiency. Optimal extractions were accomplished with octanol as the extraction solvent, 50 V as the driving force and pH 7.4 in the sample solution with the whole assembly agitated at 1000 rpm for 20 min. Under the optimized extraction conditions, the proposed technique provided good linearity (R(2) > 0.9990), repeatability (3.5-3.8%), low LODs (1.5 ng/mL), good preconcentration factors (292-316) and high recoveries (80-87%). Finally, this method was successfully used for the determination of tramadol and methadone in different body fluids including plasma and urine samples.

Determination of volatile non intentionally added substances coming from a starch-based biopolymer intended for food contact by different gas chromatography-mass spectrometry approaches

“…Furthermore, APGC is compatible with higher carrier gas flow rates, and there is no need of breaking the vacuum when general maintenance of the ion source is required. In literature, two main ionization processes have been described for APGC in some detail [30][31][32][33][34]. In brief, ionization is affected by the source environmental conditions.…”

Improved in-tube electro-membrane extraction followed by high-performance liquid chromatography for simple and selective determination of ionic compounds: Optimization by central composite design

“…In order to deal with this problem, Pedersen-Bjergaard et al [23][24][25][26] have introduced a microextraction technique called the electro-membrane extraction (EME). The extraction principle in EME is based on the electro-kinetic migration of ionized compounds by the application of an electrical potential difference [27][28][29][30][31][32]. In this method, the ionized compounds migrate across the supported liquid membrane (SLM) from an aqueous sample solution into an aqueous acceptor that is located inside the lumen of a hollow fiber.…”

Simultaneous determination of benzene, toluene, ethylbenzene, and xylene metabolites in human urine using electromembrane extraction combined with liquid chromatography and tandem mass spectrometry

“…Recently, a new sample preparation method known as electromembrane extraction (EME) has been developed . EME is a microextraction technique based on hollow fiber liquid‐phase microextraction (HF‐LPME) for the extraction of charged compounds .…”

“…A previous report showed that several basic drugs were extracted more than three times faster with EME than with HF‐LPME . Typically, EME is performed with HPLC–UV or LC–MS; however, several new trials combining EME with GC–MS have recently been presented . EME has been widely used for extraction of acidic or basic compounds from various matrices such as wastewater, plant samples, biological fluids, and dairy products , .…”