Magnetic solid-phase extraction technique based on Fe3O4@coPPy-PTH nanocomposite for extraction of cobalt, chromium, and nickel prior to determination by microsample injection system-flame atomic absorption spectrometry in alcoholic and nonalcoholic beverages.

A novel Fe3O4@coPPy-PTH nanocomposite-based sorbent was prepared via in situ oxidative polymerization using Fe3O4 nanoparticles with spherical and flower-like morphologies of thiophene and pyrrole as the feedstocks. The synthesized nanocomposite displayed sensitive extraction and determination of metal ions Co(II), Cr(III), and Ni(II) without a chelating agent, followed by microsample injection system-flame atomic absorption spectrometry. Advanced spectroscopic and imaging techniques including scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy were used to characterize the composition and morphology of the Fe3O4@coPPy-PTH nanocomposite. SEM observations showed that the size of the Fe3O4 nanoparticles changed from 30 nm to 120 nm in diameter after copolymer (PPy-PTH) coating. The Fe3O4@coPPy-PTH nanocomposite has good dispersion properties and stability in strong acid solutions. For effective extraction of the studied analytes, the influence of sample pH, volume of sample solution and eluent, amount of adsorbent, and interference of coexisting metal ions were optimized. Under the optimum conditions, preconcentration factors were obtained as 25 for all analytes. The calibration curves were linear in the range of 0.0-10.0 µg L-1 with coefficients of determination (R2) greater than 0.9957 for all three analytes. Limits of detection (S/N = 3) were calculated in the range of 0.17-0.23 µg L-1. Precision values, expressed as relative standard deviations, were lower than 3.0%, and relative recoveries were obtained in the range of 88.6%-103.6%. The proposed method (Fe3O4@coPPy-PTH/MSPE/MIS-FAAS) was successfully applied to extract and determine the studied metal ions in beer, wine, and nonalcoholic beverage samples.

An Ultrasensitive Electrochemical Sensor Using Banana Peel Activated Carbon/NiFe2O4/MnCoFe-LDH Nanocomposites for Anticancer Drug Determination.

In the current study, we report the synthesis of a novel composite material composed of banana peel activated carbon (BPAC), nickel iron oxide (NiFe2O4), and manganese cobalt iron layered double hydroxide (MnCoFe-LDH) to create a high-performance electrochemical sensor to detect Palbociclib (PLB). The composite was successfully immobilized on a glassy carbon electrode (GCE) surface to create a modified electrode. The performance of the electrode was thoroughly evaluated, considering parameters such as electroactive surface areas (ESA), electron transfer rate constant (k0), and exchange current density (j0). The developed BPAC/NiFe2O4/MnCoFe-LDH/GCE exhibited a wide linear dynamic range of 0.01-13.0 µM for PLB concentration, accompanied by a detection limit at a low level (3.5 nM). Furthermore, it can be applied to the determination of PLB in human urine and pharmaceutical samples with excellent recoveries (98.5-102.9%) and RSD values lower than 3%, establishing its potential for precise PLB determination in pharmaceutical and biological samples. This research contributes to the advancement of electrochemical sensor technology for the detection of important anticancer drugs in real-world applications.

Carbon fibers modified with polypyrrole for headspace solid phase microextraction of trace amounts of 2-pentyl furan from breath samples.

This study introduces micrometric carbon strands as a suitable fiber for headspace solid phase microextraction. Compared to previous supports, carbon fibers have mechanical flexibility, wide thermal expansion, and a large surface area, which is an important factor in headspace solid phase microextraction. The electrophoretic technique was applied to modify the surface of stainless steel and carbon fibers with polypyrrole. Modified carbon fibers were used for extraction of 2-pentylfuran (2-PF) as a model analyte from patients' breath and coffee samples. 2-PF belongs to the furan family, which was suggested as a biomarker for Aspergillus fumigatus and was classified as a possible carcinogen. 2-PF can be found in many heat-processed foods and drinks. The separation and detection of the analyte was performed by gas chromatography coupled to mass spectrometry. The effective factors in the extraction performance of the analyte by carbon fiber supports were investigated and optimized. Under optimized extraction conditions (temperature, 20 °C; time, 15 min; desorption temperature, 200 °C; desorption time, 2 min; salt concentration, 10% w/v; and stirring rate, 700 rpm), the limit of detection was calculated as 0.05 ng mL-1, whereas repeatability and fiber-to-fiber reproducibility (RSD %) was found to be in the range of 3.2-4.1%. The experimental results showed that the proposed fiber had greater extraction performance for 2-pentylfuran.

Extraction of antidepressant drugs in biological samples using alkanol-based nano structured supramolecular solvent microextraction followed by gas chromatography with mass spectrometric analysis.

In the present study, a supramolecular solvent was formed from reverse micelle aggregates of octanol. The proposed supramolecular solvent was used for rapid extraction of some antidepressants drugs including amitriptyline, imipramine, desipramine, maprotiline, sertraline, and doxepin from biological samples. Alkanol-based supramolecular solvents have a unique array of physicochemical properties, making them a very attractive alternative to replace organic solvents in analytical extractions. The parameters affecting the extraction of target analytes (i.e., the volume of tetrahydrofuran and octanol as the major components comprising the supramolecular solvent, chain length of alkanols, sample solution pH, salt addition, and ultrasonic time) were investigated and optimized by factor by factor optimization method. Under the optimum conditions, preconcentration factors of 470, 490, 460, 385, 370, and 430 were obtained for amitriptyline, doxepin, imipramine, desipramine, maprotiline, and sertraline, respectively. The linear ranges and coefficients of determination (R2 ) were obtained in the range of 0.01-100 µg/L and 0.9974-0.9991, respectively. Also the limits of detection (S/N = 3) of 0.003-0.03 µg/L, and precisions (n = 5) of 4.9-8.9% were calculated. Finally, the method was successfully applied for the extraction of antidepressant drugs in biological samples, and relative recoveries in the range of 91-102% were obtained.

A new generation of nano-structured supramolecular solvents based on propanol/gemini surfactant for liquid phase microextraction.

A new supramolecular solvent (SUPRAS) made up of aggregates of gemini surfactant was introduced. A microextraction method, based on the SUPRAS followed with high performance liquid chromatography-ultraviolet detection, was applied for the determination of parabens in cosmetics, beverages and water samples. A SUPRAS is a nano-structured liquid made up of surfactant aggregates synthesized through a self-assembly process. In the present work, a new gemini-based SUPRAS was introduced. Methyl paraben (MP), ethyl paraben (EP), and propyl paraben (PP) were extracted on the basis of π-cation and Van der Waals interactions into the SUPRAS. The parameter affecting the extraction of target analytes (i.e., the amount of surfactant and volume of propanol as major components comprising the supramolecular solvent, sample solution pH, salt addition, ultrasonic and centrifugation time) were investigated and optimized by one-variable-at-a-time method. Under the optimum conditions, the preconcentration factors of 98, 143 and 156 were obtained for MP, EP and PP, respectively. The linearity ranged from 0.5 to 0.7-200 µg L-1 with the correlation of determination of (R2) ≥ 0.9938. The gemini-based SUPRAS followed by HPLC-UV has been found to have excellent detection sensitivity with a limit of detection (LOD, S/N = 3) of 0.5 µg L-1 for EP and PP, and 0.7 µg L-1 for MP. Good recoveries over the range of 92.0-108.3% assured the accuracy of the amount of parabens distinguished in the non-spiked samples.