Bioavailability of flumequine and diclofenac in mice exposed to a metal-drug chemical cocktail. Evaluation of the protective role of selenium.

Background And Purpose: Organisms, including humans, are subjected to the simultaneous action of a wide variety of pollutants, the effects of which should not be considered in isolation, as many synergies and antagonisms have been found between many of them. Therefore, this work proposes an in vivo study to evaluate the effect of certain metal contaminants on the bioavailability and metabolism of pharmacologically active compounds. Because the most frequent entry vector is through ingestion, the influence of the gut microbiota and the possible protective effects of selenium has been additionally evaluated.

Electromembrane extraction of peptides based on hydrogen bond interactions.

Background: Electromembrane extraction (EME) of peptides reported in the scientific literature involve transfer of net positively charged peptides from an aqueous sample, through a liquid membrane, and into an aqueous acceptor solution, under the influence of an electrical field. The liquid membrane comprises an organic solvent, containing an ionic carrier. The purpose of the ionic carrier is to facilitate peptide solvation in the organic solvent based on ionic interactions.

Green strategies using solvent-free biodegradable membranes in microfluidic devices. Liquid phase microextraction and electromembrane extraction.

In this work, a novel solvent-free microfluidic method based liquid phase microextraction has been proposed for the first time. A comprehensive study of liquid phase microextraction (LPME) and electromembrane extraction (EME) implemented in microfluidic formats has been carried out to investigate the efficiency of biodegradable membranes (such as agarose) without organic solvent to develop fully environmental microfluidic methods. For this study, non-polar and polar basic compounds (five) were selected as model analytes and different agarose membrane compositions were synthesized and tested with and without organic solvent (solvent-free).

An improved microfluidic device to enhance the enrichment factors in liquid phase microextraction: application to the simultaneous extraction of polar and non-polar acids in biological samples.

A new microfluidic device to enhance the enrichment factor in miniaturized systems is proposed. The microfluidic system was design for liquid phase microextractions, and it was applied to the simultaneous extraction of acidic compounds of a wide range of polarity (0.5 < log P < 3).

A rapid and versatile microfluidic method for the simultaneous extraction of polar and non-polar basic pharmaceuticals from human urine.

In sample preparation, simultaneous extraction of analytes of very different polarity from biological matrixes represents a challenge. In this work, verapamil hydrochloride (VRP), amitriptyline (AMP), tyramine (TYR), atenolol (ATN), metopropol (MTP) and nortriptyline (NRP) were used as basic model analytes and simultaneously extracted from urine samples by liquid-phase microextraction (LPME) in a microfluidic device. The model analytes (target compounds) were pharmaceuticals with 0.

A green microfluidic method based liquid phase microextraction for the determination of parabens in human urine samples.

Development of green approaches have emerged as a challenge that highlight the pressing need for nontoxic solvents, miniaturized method and bio-degradable materials. In this regard, an environmentally-friendly microfluidic system based on natural deep eutectic solvents (DESs) immobilized in agarose membranes was developed to extract parabens from urine samples for the first time. A comprehensive study of the support liquid membrane showed that only 3 µL of camphor and thymol (2:1 molar ratio) was an interesting option as a substitute for conventional (toxic) solvents used to date.

Optofluidic systems enabling detection in real samples: A review.

Optofluidics, understood as the synergistic combination between microfluidics and photonics, has been at the forefront of the scientific research due to its outmatching properties: on the one hand, microfluidics allows the handling of minute amounts of liquid samples at the microscale. On the other hand, photonics has proved to outmatch other detection methods (e.g.

Microfluidic liquid-phase microextraction based on natural deep eutectic solvents immobilized in agarose membranes.

In liquid-phase microextraction (LPME), the sample and the acceptor are separated by a synthetic organic solvent, which is immobilized in a porous polymeric membrane of polypropylene or polyvinylidene fluoride. The organic solvent serves as extraction phase, while the polymeric membrane serves as support membrane. The combination of extraction phase and support membrane is termed supported liquid membrane (SLM).

A microchip device based liquid-liquid-solid microextraction for the determination of permethrin and cypermethrin in water samples.

In this work, for the first time, a microchip device integrating liquid-liquid-solid phase microextraction is presented. As a novel approach to microchip systems, liquid-liquid-solid microextraction was performed in a sandwiched microchip device. The microchip device consisted of three poly(methyl methacrylate) layers along with a double "Y"-shaped microchannel.

Monitoring of pharmaceuticals in aquatic biota (Procambarus clarkii) of the Doñana National Park (Spain).

In this work the presence of different pharmaceuticals at Doñana National Park (Spain) and their main entry sources (input source or entry points) have been stated over the 2011-2016 years period. Twenty-three selected pharmaceuticals (corresponding to eight therapeutic families) were evaluated in crayfish and water samples from Doñana National Park (Spain) (six sampling points selected in order to cover different possible pollution sources into and surrounding the Park). The multiresidue determination was carried out using enzymatic-microwave assisted extraction prior to high performance liquid chromatography mass spectrometry detection.

A selective and efficient microfluidic method-based liquid phase microextraction for the determination of sulfonamides in urine samples.

Liquid phase microextraction (LPME) into a microfluidic has undergone great advances focused on downscaled and miniaturized devices. In this work, a microfluidic device was developed for the extraction of sulfonamides in order to accelerate the mass transfer and passive diffusion of the analytes from the donor phase to the acceptor phase. The subsequent analysis was carried out by high performance liquid chromatography with UV-DAD (HPLC-DAD).

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).

Green microfluidic liquid-phase microextraction of polar and non-polar acids from urine.

In this work, hippuric acid (log P = 0.5), anthranilic acid (log P = 1.3), ketoprofen (log P = 3.

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.

An overview on the recent applications of agarose as a green biopolymer in micro-extraction-based sample preparation techniques.

Introducing a myriad array of chemicals in different industrial fields has made sample preparation inevitable for trace analysis. Classical extraction techniques such as solid phase extraction (SPE) and liquid-liquid extraction (LLE) techniques often suffer from tedious procedures (huge workload) and hazards to personnel and environment (samples and reagents are often user-unfriendly and processed in high amounts). For addressing these problems, microextraction techniques have been introduced.

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.

Comparison of three electromembrane-based extraction systems for NSAIDs analysis in human urine samples.

A comparative study on the extraction efficiency of five non-steroidal anti-inflammatories was carried out using three different electromembrane extraction (EME) devices with different geometries. The employed setups were (a) a hollow fiber configuration (HF-EME), (b) a microfluidic device that allows working in semi-dynamic mode (μF-EME), and (c) a static miniaturized flat membrane device (FM-EME). Each system was applied to the extraction of salicylic acid (SAC), ketoprofen (KTP), naproxen (NAX), diclofenac (DIC), and ibuprofen (IBU) and subsequent determination by high-performance liquid chromatography with UV and fluorescence detection (HPLC/UV-DAD-FLD).

A Method for the Determination of Veterinary Drugs from Different Therapeutic Classes in Animal Urine.

A rapid, precise and robust HPLC separation procedure has been developed and optimized for the determination of a series of drugs of different therapeutic classes: chlortetracycline, oxitetracycline, cefoperazone, diclofenac, tiamphenicol, marbofloxacin, ciprofloxacin, danofloxacin, enrofloxacin and flumequine. The chromatographic method used a monolithic C18 column and both diode array and fluorescence detection. This procedure was validated for the analysis of drugs in cow urine, using a simple and fast procedure with methanol/acetonitrile, allowing the simultaneous and efficient extraction of most of the studied drugs.

Liquid - Phase microextraction and electromembrane extraction in millifluidic devices:A tutorial.

This tutorial discusses how to integrate different microextraction procedures into millifluidic platforms and the applicability of such systems for the determination of acidic and basic drugs. Sample preparation techniques have been downscaled into a millifluidic format and the replacement of conventional analytical systems by miniaturized alternatives has increased during recent years due to the small volume consumption of toxic solvents and sample required, shorter extraction times, simple-handling and low cost, among others. This review comprehensively summarizes the development of liquid-liquid extraction into a millifluidic device in a three-phase configuration, with focus on (a) historical development, (b) extraction mechanisms and performance, (c) operation modes and automatization, (d) operational parameters, (e) applications, and (f) future directions and perspectives.

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 New Microchip Design. A Versatile Combination of Electromembrane Extraction and Liquid-Phase Microextraction in a Single Chip Device.

For the first time, a novel and versatile microfluidic device was developed to achieve the possibility of combining different extraction principles using a miniaturized approach for the extraction of different classes of analytes. This novel microchip is composed of a sandwich of three poly(methyl methacrylate) (PMMA) layers. Four channels allowed the combination of electromembrane extraction (EME) and liquid-phase microextraction (LPME) in three different ways: (I) EME and LPME, (II) EME and EME, or (III) LPME and LPME.

Multiresidue determination of 21 pharmaceuticals in crayfish (Procambarus clarkii) using enzymatic microwave-assisted liquid extraction and ultrahigh-performance liquid chromatography-triple quadrupole mass spectrometry analysis.

In this paper, a multiresidue enzymatic-microwave assisted extraction prior to ultrahigh performance liquid chromatography and triple quadrupole mass spectrometry analysis has been developed for the determination of 21 pharmaceuticals in crayfish (Procambarus Clarkii) samples. The analysed compounds corresponding to 6 therapeutic families were: fluoroquinolones (ciprofloxacin, danofloxacin, enrofloxacin, flumequine, gatifloxacin, grepafloxacin, marbofloxacin and norfloxacin); tetracyclines (chlortetracycline and oxytetracycline); sulphonamides (sulfamethoxazole, sulfadiazine, sulfamethazine, sulfamerazine); penicillins (amoxicillin); anfenicols (chloramphenicol, thiamphenicol and florfenicol); non-steroidal anti-inflammatory drugs (ibuprofen and salicylic acid) and trimethoprim an antibiotic that is frequently co-administered with sulfamethoxazole. The main factors affecting the extraction efficiency were optimized for 0.

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).

Continuous electromembrane extraction coupled with mass spectrometry - Perspectives and challenges.

This tutorial discusses continuous electromembrane extraction (c-EME) coupled directly to mass spectrometry (MS), and the applicability of such systems for on-line and real-time monitoring of in-vitro drug metabolism. Parent drug substances and corresponding drug metabolites are extracted from the metabolic reaction mixture, through a supported liquid membrane (SLM), and into an acceptor solution on the other side. Extraction is accomplished using an external electrical field sustained over the SLM.