Dispersive micro-solid-phase extraction of benzodiazepines from biological fluids based on polyaniline/magnetic nanoparticles composite

Polypyrrole-modified magnetic multi-walled carbon nanotube-based magnetic solid-phase extraction combined with dispersive liquid–liquid microextraction followed by UHPLC-MS/MS for the analysis of sulfonamides in environmental water samples

Polypyrrole modified magnetic multi-walled carbon nanotubes were prepared and applied as an efficient adsorbent for magnetic solid-phase extraction.

Efficient removal of anti-inflammatory phenylbutazone from an aqueous solution employing a composite material based on poly(aniline-co-pyrrole)/multi-walled carbon nanotubes

Poly(Ani-co-Py)/MWCNT was synthesized by chemical oxidation in a triple-phase interface system and presented a high capacity for the removal of PBZ from wastewater.

Simple and selective detection of quercetin in extracts of plants and food samples by dispersive-micro-solid phase extraction based on core–shell magnetic molecularly imprinted polymers

In the present study, a D-μ-SPE clean-up method was established for the analysis of quercetin in extracts of plants and food samples using a magnetic molecularly imprinted polymer as the sorbent by HPLC-UV detection.

Advances in organic-inorganic hybrid sorbents for the extraction of organic and inorganic pollutants in different types of food and environmental samples

The efficiency of the extraction and removal of pollutants from food and the environment has been an important issue in analytical science. By incorporating inorganic species into an organic matrix, a new material known as an organic-inorganic hybrid material is formed. As it possesses high selectivity, permeability, and mechanical and chemical stabilities, organic-inorganic hybrid materials constitute an emerging research field and have become popular to serve as sorbents in various separaton science methods. Here, we review recent significant advances in analytical solid-phase extraction employing organic-inorganic composite/nanocomposite sorbents for the extraction of organic and inorganic pollutants from various types of food and environmental matrices. The physicochemical characteristics, extraction properties, and analytical performances of sorbents are discussed; including morphology and surface characteristics, types of functional groups, interaction mechanism, selectivity and sensitivity, accuracy, and regeneration abilities. Organic-inorganic hybrid sorbents combined with extraction techniques are highly promising for sample preparation of various food and environmental matrixes with analytes at trace levels.

Separation and preconcentration of riboflavin from human plasma using polythionine coated magnetite/hydroxyapatite nanocomposite prior to analysis by surfactant-enhanced fluorimetry

The exploration of novel adsorption properties of conductive polymers based on hybridization with biocompatible nanomaterials receives an increasing interest. In this regard, hydroxyapatite (HA) bioceramic is of critical importance mainly owing to its facile synthesis, high surface area, economic and low toxicity in biological environments. In this work, we first prepared and characterized a magnetite/hydroxyapatite (Fe₃O₄/HA) nanocomposite using the bio-waste chicken eggshell via an attractive green way that involved low cost and irrespective of toxicity. Then, polythionine as a novel class of conductive polymers was in situ coated on the synthesized magnetic bioceramic for the separation and preconcentration of riboflavin (vitamin B₂) in human plasma before its fluorimetric determination. Considering the putative role of riboflavin in protecting against cancer and cardiovascular diseases, it is essential to evaluate this vitamin in biological fluids. The described method possesses a linear range of 0.75-262.5μgL^-1 (R²=0.9985) and a detection limit of 0.20μgL^-1 (signal-to-noise ratio of 3). The relative standard deviations (RSDs) for single-sorbent repeatability and sorbent-to-sorbent reproducibility were less than 4.0% and 7.6% (n=5), respectively. The respective enrichment factor and extraction recovery of the method found to be 35.7 and 98.4%. The analytical performance of method for riboflavin was characterized by good consistency of the results with those obtained by the enzyme-linked immunosorbent assay (ELISA) conventional method (p-value of <0.05). The optimized protocol intended for control determinations of riboflavin in human subjects and is addressed to clinical laboratories.

Polyaniline-deposited cellulose fiber composite prepared via in situ polymerization: enhancing adsorption properties for removal of meloxicam from aqueous media

Polyaniline (PAni), cellulose fiber (CF) and a PAni–CF composite, which were characterized by infrared spectroscopy, scanning electron microscopy and thermogravimetry, were investigated in adsorption studies of meloxicam (MLX) from aqueous media.

Determination of carboxylic acids in non-alcoholic beer samples by an ultrasonic-assisted dispersive micro-solid phase extraction based on Ni/Cu-Al layered double hydroxide nanocomposites followed by gas chromatography

Magnetically separable layered double hydroxide Ni/CuAl-LDH nanocomposites were synthesized and employed as ultrasonic-assisted dispersive micro-solid phase extraction (UA-D-μSPE) sorbent to extract several carboxylic acids (namely propionic, butyric, pentanoic, hexanoic, heptanoic, octanoic, and decanoic) from non-alcoholic beer samples. Ni/CuAl-LDH sorbent was characterized by Fourier transform-infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). Effective variables such as amount of sorbent (mg), pH and ionic strength of sample solution, volume of eluent solvent (μL), vortex, and ultrasonic times (min) were investigated via fractional factorial design (FFD). The significant variables were optimized by a Box-Behnken design and combined by a desirability function (DF). Under optimized conditions, the calibration graphs of analytes were linear in a concentration range of 0.05-100μg/mL and had correlation coefficients more than 0.997. The limits of detection and quantification were in the ranges of 16-40μg/L and 53-133μg/L, respectively. This procedure was successfully employed in the determination of target analytes in spiked beer samples, and the relative mean recoveries ranged from 87 to 110%.

Determination of propranolol and carvedilol in urine samples using a magnetic polyamide composite and LC–MS/MS

Aim: β-blockers are compounds that bind with adrenoreceptors hindering their interaction with adrenalin and noradrenalin. They are clinically relevant and they are also used in some sport as doping agents. Results: A new method based on the combination of dispersive micro-solid phase extraction and LC–MS/MS has been developed to determine propranolol and carvedilol in urine samples. For this purpose a magnetic-polyamide composite is synthesized and used as sorbent. Working under the optimum conditions, the method provides limits of detection and quantification in the range of 0.1–0.15 μg/l and 0.3–0.5 μg/l, for carvedilol and propranolol, respectively. The precision, expressed as RSD, was better than 9.6% and the relative recoveries varied between 73.7 and 81.3%. Conclusion: The methodology is appropriate for the determination of β-blockers in urine samples at the low microgram per liter range for therapeutic purposes.

Extraction of phenolic compounds from water samples by dispersive micro-solid-phase extraction

In this article, the use of magnetically separable sorbent polyaniline/silica-coated nickel nanoparticles is evaluated under a dispersive micro-solid-phase extraction approach for the extraction of phenolic compounds from water samples. The sorbent was prepared by in situ chemical polymerization of aniline on the surface of silica-modified nickel nanoparticles and was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, and vibrating sample magnetometry. Effective variables such as amount of sorbent (milligrams), pH and ionic strength of sample solution, volume of eluent solvent (microliters), vortex, and ultrasonic times (minutes) were investigated by fractional factorial design. The significant variables optimized by a Box-Behnken design were combined by a desirability function. Under the optimized conditions, the calibration graphs of analytes were linear in a concentration range of 0.02-100 μg/mL, and with correlation coefficients more than 0.999. The limits of detection and quantification were in the ranges of 10-23 and 33-77 μg/L, respectively. This procedure was successfully employed in the determination of target analytes in spiked water samples; the relative mean recoveries ranged from 96 to 105%.

Poly(2-aminobenzothiazole)-coated graphene oxide/magnetite nanoparticles composite as an efficient sorbent for determination of non-steroidal anti-inflammatory drugs in urine sample

In this study, for the first time, 2-aminobenzothiazole monomer was polymerized on Fe3O4 NPs, graphene oxide/Fe3O4 (GO/Fe3O4) and graphene/Fe3O4 (G/Fe3O4) nanocomposites. The synthesized magnetic nanosorbents were characterized by various techniques. The extraction ability of these nanosorbents including Fe3O4, GO/Fe3O4, G/Fe3O4, Fe3O4@poly(2-aminobenzothiazole) (Fe3O4@PABT), GO/Fe3O4@PABT and G/Fe3O4@PABT were compared for dispersive-micro-solid phase extraction of three non-steroidal anti-inflammatory drugs. The results revealed that GO/Fe3O4@PABT nanocomposite demonstrates higher extraction efficiency for naproxen, diclofenac and ibuprofen as selected model analytes. Following the sorption and elution steps, the model analytes were quantified by high performance liquid chromatography-photo diode array detection. Afterwards, a central composite design methodology combined with desirability function approach was applied to find out the optimal experimental conditions. Under the optimized conditions, the limits of detection and linear dynamic ranges were achieved in the range of 0.07-0.3 μg L(-1) and 0.25-2000 μg L(-1), respectively. The percent of extraction recovery was 87.4, 85.5 and 90.5% for naproxen, diclofenac and ibuprofen, respectively. The obtained relative standard deviation (n=5) was 7.2, 5.4 and 6.4% for naproxen, diclofenac and ibuprofen, respectively. Ultimately, this method was employed for urinary monitoring of the target analytes and satisfactory results were obtained.

Zein bio-nanoparticles: a novel green nanopolymer as a dispersive solid-phase extraction adsorbent for separating and determining trace amounts of azorubine in different foodstuffs

A new, easy, and green method using zein nanoparticles as a dispersive solid-phase extraction (DSPE) adsorbent has been used for the preconcentration of azorubine (a well-known chemical dye additive) as a model compound in foodstuffs.

Preparation and characterization of a composite based on polyaniline, polypyrrole and cigarette filters: adsorption studies and kinetics of phenylbutazone in aqueous media

PAni–PPy–CFs composite was prepared by a static one-step triple-phase interfacial reaction, in which the PAni and PPy particles were formed and aggregated on CFs resulting in a composite with fibrous domains and good adsorption proprieties.

Superparamagnetic Fe3 O4 @SiO2 core-shell composite nanoparticles for the mixed hemimicelle solid-phase extraction of benzodiazepines from hair and wastewater samples before high-performance liquid chromatography analysis

Magnetic Fe3 O4 /SiO2 composite core-shell nanoparticles were synthesized, characterized, and applied for the surfactant-assisted solid-phase extraction of five benzodiazepines diazepam, oxazepam, clonazepam, alprazolam, and midazolam, from human hair and wastewater samples before high-performance liquid chromatography with diode array detection. The nanocomposite was synthesized in two steps. First, Fe3 O4 nanoparticles were prepared by the chemical co-precipitation method of Fe(III) and Fe(II) as reaction substrates and NH3 /H2 O as precipitant. Second, the surface of Fe3 O4 nanoparticles was modified with shell silica by Stober method using tetraethylorthosilicate. The Fe3 O4 /SiO2 composite were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. To enhance their adsorptive tendency toward benzodiazepines, cetyltrimethylammonium bromide was added, which was adsorbed on the surface of the Fe3 O4 /SiO2 nanoparticles and formed mixed hemimicelles. The main parameters affecting the efficiency of the method were thoroughly investigated. Under optimum conditions, the calibration curves were linear in the range of 0.10-15 μgmL(-1) . The relative standard deviations ranged from 2.73 to 7.07%. The correlation coefficients varied from 0.9930 to 0.9996.

Determination of Hg(II) ions in sea food samples after extraction and preconcentration by novel Fe3O 4@SiO 2@polythiophene magnetic nanocomposite

This work describes a novel Fe3O4@SiO2@polythiophene magnetic nanocomposite and its application in the preconcentration of Hg(II) ions. The parameters affecting the preconcentration procedure were opted by a Box-Behnken design through response surface methodology. Three factors (uptake time, magnetic nanosorbent amount, and pH of sample) were selected as the main factors affecting the sorption step, while four variables (type, volume and concentration of the eluent as well as the elution time) were selected as main factors in the optimization study of the elution step. Following the sorption and elution of Hg(II), it was quantified by cold vapor atomic absorption spectrometry. Under the optimum condition, the limit of detection was 0.02 ng mL(-1) and all the relative standard deviations were less than 9.2 %. The obtained sorption capacity of this new sorbent was 59 mg g(-1). Finally, this nanocomposite was successfully applied to the rapid extraction of trace quantities of Hg(II) ions in sea food samples and satisfactory results were obtained.

Polymer–nanoparticles composites in bioanalytical sample preparation

The term composite refers to a class of synthetic materials made from different constituents which exhibit final properties which are different from those of the individual components. Composites have been extensively used in the sample treatment context as sorbents since the resulting solid presents better extraction efficiency. In this realm, polymeric nanocomposites are raised as a powerful alternative. They can be tailored-synthesized for selectivity enhancement or include a magnetic core to simplify the extraction/elution process. This review article points out the relevance of such nanomaterials in bioanalysis. Several synergic combinations of nanoparticles (magnetic, carbon-based) as well as polymeric coatings (conventional, conductive or molecularly imprinted) are commented on. Finally, the potential of biopolymers in the microextraction field is briefly highlighted.

Coextraction of acidic, basic and amphiprotic pollutants using multiwalled carbon nanotubes/magnetite nanoparticles@polypyrrole composite

The simultaneous extraction of acidic, basic and amphiprotic pollutants from various samples is a considerable and disputable concept in sample preparation strategies. In this study, for the first time, coextraction of acidic, basic and amphiprotic pollutants (polar and apolar) with multiwalled carbon nanotubes/Fe3O4@polypyrrole (MWCNTs/Fe3O4@PPy) composite based dispersive micro-solid phase extraction followed by high performance liquid chromatography-photo diode array detection was introduced. Firstly, the extraction efficiency of various magnetic nanosorbents including Fe3O4, MWCNTs/Fe3O4, graphene oxide/Fe3O4 (GO/Fe3O4), Fe3O4@PPy, MWCNTs/Fe3O4@PPy and GO/Fe3O4@PPy were compared. The results revealed that MWCNTs/Fe3O4@PPy nanocomposite has higher extraction efficiency for five selected model analytes (4-nitrophenol, 3-nitroaniline, 2,4-dichloroaniline, 3,4-dichloroaniline and 1-amino-2-naphthol). Box-Behnken design methodology combined with desirability function approach was applied to find out the optimal experimental conditions. The opted conditions were: pH of the sample, 8.2; sorbent amount, 12 mg; sorption time, 5.5 min; salt concentration, 14% w/w; type and volume of the eluent, 120 μL acetonitrile; elution time; 2 min. Under the optimum conditions detection limits and linear dynamic ranges were achieved in the range of 0.1-0.25 μg L(-1) and 0.5-600 μg L(-1), respectively. The percent of extraction recovery and relative standard deviations (n=5) were in the range of 45.6-82.2 and 4.0-8.5, respectively. Ultimately, the applicability of this method was successfully confirmed by analyzing rain, snow and river water samples and satisfactory results were obtained.