Graphene oxide/Fe3O4@polythionine nanocomposite as an efficient sorbent for magnetic solid-phase extraction followed by high-performance liquid chromatography for the determination of duloxetine in human plasma

Determination of furfurals in baby food samples after extraction by a novel functionalized magnetic porous carbon

Herein, a novel polypyrrole-polyaniline functionalized magnetic porous carbon (MPC@PPy-PANI) composite material was fabricated and utilized for the separation/extraction of furfurals from baby food and dry milk samples. In this way, magnetite@silica nanoparticles were first synthesized, and then a magnetic metal–organic framework (MMIL-101(Fe)) was prepared. After that, the MMIL-101(Fe) was pyrolyzed in a neutral atmosphere to obtain MPC. Ultimately, the MPC was functionalized with a co-polymer of aniline–pyrrole via oxidation polymerization. The synthesis of MPC@PPy-PANI was confirmed with FT-IR spectroscopy, SEM, TEM, VSM, and XRD techniques. Furfural and hydroxymethyl furfural were selected as the model analytes, which were separated/quantified on an HPLC-UV instrument. The LODs, LOQs, and linear dynamic ranges (LDRs) were in the range of 0.3–0.7 μg kg⁻¹, 1.0–2.5 μg kg⁻¹, and 1.0–600 μg kg⁻¹, respectively. Repeatability of the method was studied as an RSD parameter, and was located in the range of 5.5–6.8% (within-day, n = 5) and 8.2–9.4% (between-day, n = 3 days). The applicability of the proposed method was established by analyzing several baby food and dry milk samples. The relative recovery (RR%) and repeatability were located in the range of 86–111% and 3.3–10.1%, respectively, showing excellent accuracy and precision of the method.

Herein, a novel polypyrrole-polyaniline functionalized magnetic porous carbon (MPC@PPy- PANI) composite material was fabricated and utilized for the separation/extraction of furfurals from baby food and dry milk samples.

Synthesis and characterization of a novel magnetic porous carbon coated with poly(p-phenylenediamine) and its application for furfural preconcentration and determination in baby food and dry milk powder samples

The aim of the current research is to develop a MSPE method for the determination of furfural in baby food and dry milk samples. In this regard, a novel magnetic porous carbon composite coated with poly(p-phenylenediamine) was fabricated, characterized, and then applied to the preconcentration/extraction of furfurals from baby food and dry milk powder samples. Initially, magnetic nanoparticles (Fe₃O₄) were synthesized, and then coated with a metal–organic framework layer named MIL-101(Fe). Afterward, the magnetic MIL-101(Fe) was subjected to calcination under a nitrogen atmosphere and magnetic porous carbon was achieved. Finally, a layer of poly(p-phenylenediamine) was coated on the magnetic porous carbon. The structure of the nanocomposite was investigated with various methods, including FT-IR spectroscopy, electron microcopies (SEM and TEM), VSM, and XRD. The fabricated nanocomposite was applied in magnetic solid-phase extraction of furfural and hydroxymethyl furfural and their determination with liquid chromatography. The effect of experimental variables was explored by using an experimental design approach. The LODs and linear range for the target furfurals were 1.0–2.0 μg kg⁻¹ and 3.0–500 μg kg⁻¹, respectively. The method's repeatability was explored using RSD values and was found to be in the range of 5.2–6.4% (one-day, n = 5) and 9.1–10.8% (day to day, n = 3). Eventually, this new method was employed for the extraction/quantification of target compounds in baby food and dry milk powder samples.

In this research, a novel magnetic porous carbon composite coated with poly(p-phenylenediamine) was fabricated, characterized, and then applied to the preconcentration/extraction of furfurals from baby food and dry milk powder samples.

Green Bioanalytical Applications of Graphene Oxide for the Extraction of Small Organic Molecules

Bioanalysis is the scientific field of the quantitative determination of xenobiotics (e.g., drugs and their metabolites) and biotics (e.g., macromolecules) in biological matrices. The most common samples in bioanalysis include blood (i.e., serum, plasma and whole blood) and urine. However, the analysis of alternative biosamples, such as hair and nails are gaining more and more attention. The main limitations for the determination of small organic compounds in biological samples is their low concentration in these matrices, in combination with the sample complexity. Therefore, a sample preparation/analyte preconcentration step is typically required. Currently, the development of novel microextraction and miniaturized extraction techniques, as well as novel adsorbents for the analysis of biosamples, in compliance with the requirements of Green Analytical Chemistry, is in the forefront of research in analytical chemistry. Graphene oxide (GO) is undoubtedly a powerful adsorbent for sample preparation that has been successfully coupled with a plethora of green extraction techniques. GO is composed of carbon atoms in a sp² single-atom layer of a hybrid connection, and it exhibits high surface area, as well as good mechanical and thermal stability. In this review, we aim to discuss the applications of GO and functionalized GO derivatives in microextraction and miniaturized extraction techniques for the determination of small organic molecules in biological samples.

Fabrication of ZIF-71/Fe3O4/polythionine nanoarray-functionalized carbon cotton cloth for simultaneous extraction and quantitation of febuxostat and diclofenac

Synthesis of a material based on carbonized cotton cloth/zeolite imidazolate framework was applied to ultrasound-assisted dispersive magnetic solid-phase extraction and high-performance liquid chromatography-ultraviolet to detect diclofenac and febuxostat in human plasma.

Magnetic Solid-Phase Extraction of Organic Compounds Based on Graphene Oxide Nanocomposites

Graphene oxide (GO) is a chemical compound with a form similar to graphene that consists of one-atom-thick two-dimensional layers of sp²-bonded carbon. Graphene oxide exhibits high hydrophilicity and dispersibility. Thus, it is difficult to be separated from aqueous solutions. Therefore, functionalization with magnetic nanoparticles is performed in order to prepare a magnetic GO nanocomposite that combines the sufficient adsorption capacity of graphene oxide and the convenience of magnetic separation. Moreover, the magnetic material can be further functionalized with different groups to prevent aggregation and extends its potential application. Until today, a plethora of magnetic GO hybrid materials have been synthesized and successfully employed for the magnetic solid-phase extraction of organic compounds from environmental, agricultural, biological, and food samples. The developed GO nanocomposites exhibit satisfactory stability in aqueous solutions, as well as sufficient surface area. Thus, they are considered as an alternative to conventional sorbents by enriching the analytical toolbox for the analysis of trace organic compounds.

Silica-coated magnetic iron oxide functionalized with hydrophobic polymeric ionic liquid: a promising nanoscale sorbent for simultaneous extraction of antidiabetic drugs from human plasma prior to their quantitation by HPLC

Herein, silica-coated iron oxide nanoparticles modified with imidazolium-based polymeric ionic liquid (Fe₃O₄@SiO₂@PIL) were fabricated as a sustainable sorbent for magnetic solid-phase extraction (MSPE) and simultaneous determination of trace antidiabetic drugs in human plasma by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). The Fe₃O₄ core was functionalized by silica (SiO₂) and vinyl layers where the ionic liquid 1-vinyl-3-octylimidazolium bromide (VOIM-Br) was attached through a free radical copolymerization process. In order to achieve hydrophobic magnetic nanoparticles and increase the merits of the sorbent, Br⁻ anions were synthetically replaced with PF₆⁻. The properties and morphology of the sorbent were characterized by various techniques and all the results illustrated the prosperous synthesis of Fe₃O₄@SiO₂@PIL. A comprehensive study was carried out to investigate and optimize various parameters affecting the extraction efficiency. The limit of detection (LOD, S/N = 3) for empagliflozin, metformin and canagliflozin was 1.3, 6.0 and 0.8 ng mL⁻¹, respectively. Linearity (0.997 ≥ r² ≥ 0.993) and linear concentration ranges of 5.0–1200.0, 20.0–1800.0 and 5.0–1000.0 ng mL⁻¹ were obtained for empagliflozin, metformin and canagliflozin, respectively. Intra-assay (3.8–7.5%, n = 9) and inter-assay (3.2–8.5%, n = 12) precisions as well as accuracies (≤9.1%) displayed good efficiency of the method. Finally, the method was applied for the quantitation of antidiabetic drugs in human plasma after oral administration and main pharmacokinetic data including T_max (h), C_max (ng mL⁻¹), AUC_0–24 (ng h mL⁻¹), AUC_0–∞ (ng h mL⁻¹), and T_1/2 (h) were evaluated.

A sustainable nanoscale core–shell modified with hydrophobic polymeric ionic liquid was fabricated for simultaneous extraction and determination of antidiabetic drugs.