Synthesis of imidazolium ionic liquid immobilized on magnetic mesoporous silica: A sorbent material in a green micro-solid phase extraction of multiclass pesticides in water

In this study, we synthesized an imidazolium ionic liquid immobilized on magnetic mesoporous silica (IL-MMS) and evaluated its performance as a sorbent material for a green micro-solid phase extraction (μ-SPE) of multiclass pesticides in water. The synthesized IL-MMS was characterized by various analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses (N2 adsorption/desorption), Vibrating Sample Magnetometer (VSM), energy-dispersive spectroscopy (EDS) and Field emission scanning electron microscopy (FESEM). Our synthesized IL-MMS demonstrated excellent magnetic properties (31.5 emu/g), high surface area (1177.4 m2/g), proper pore size (⁓4.2 nm) and volume (1.80 cm3/g). Under optimized extraction conditions, the IL-MMS exhibited a high adsorption capacity for a variety of pesticides, including organophosphates, carbamates, and pyrethroids. The proposed μ-SPE method using IL-MMS showed good linearity (R2 > 0.99), low limits of detection (LODs) ranging from 0.04 to 1.63 ng/L, and suitable recovery rate was between 82.4% and 109.8% for different pesticides. In addition, the method also exhibited excellent reproducibility, with relative standard deviations (RSDs) of less than 8% for both intra and inter-day precision. In overall, the synthesized IL-MMS has proven to be a highly promising material for sorbent-based micro-solid phase extraction (μ-SPE) of multiclass pesticides in water. With its simple, efficient, and eco-friendly approach to pesticide analysis, this method shows great potential for future pesticide detection and monitoring efforts due to its sensitivity, accuracy, and adaptability to various environmental conditions.

Bacteria-templated ZIF-8 embedded in polyacrylonitrile nanofibers as a novel sorbent for thin film microextraction of benzoylurea insecticides

In the present work, the rod-like ZIF-8 (ZIF8@E coli) was prepared by fast, easy and environmentally friendly method of biomimetic mineralization with Escherichia coli bacteria as a bio-template and was exploited for the first time in the microextraction. In this regard, electrospun nanofiber mats of polyacrylonitrile (PAN) and ZIF8@E coli were prepared by electrospinning method and used as a new sorbent for thin film microextraction (TFME) of benzoylurea insecticides such as Hexaflumuron and Teflubenzuron as model analytes. The PAN/ZIF8@E coli nanocomposite was characterized using electron scanning microscopy and various spectroscopy techniques. Factors affecting the proposed extraction method were screened and optimized using the experiment design strategy. Then, the model analytes were measured by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detector after microextraction. Satisfactory figures of merit were obtained for suggested TFME-HPLC-UV under optimum conditions. The suitable linearity varied in the range of 0.5-200 μg L-1 with R2 greater than 0.9968. The limit of detections for Hexaflumuron and Teflubenzuron were 0.12 and 0.15 μg L-1, respectively. The application of the method in the real sample was investigated by analyzing the selected analytes in environmental water and food samples. The spiking recovery of the selected analytes varied in the range of 93.0-109.8 % (RSD≤7.68). The results confirm the efficient application of this new sorbent in TFME approach. Considering the high availability, ease of production, and environmental friendliness of bacteria along with the significant improvement of metal-organic framework (MOF) growth efficiency, biomimetic mineralization is expected to be efficient method for the synthesis of ordered MOFs for use in extraction fields.

Enhancing Solid-Phase Extraction of Tamoxifen and Its Metabolites from Human Plasma Using MOF-Integrated Polyacrylonitrile Composites: A Study on CuBTC and ZIF-8 Efficacy

This study investigates electrospun fibers of metal-organic frameworks (MOFs), particularly CuBTC and ZIF-8, in polyacrylonitrile (PAN) for the solid-phase extraction (SPE) of Tamoxifen (TAM) and its metabolites (NDTAM, ENDO, and 4OHT) from human blood plasma. The focus is on the isolation, pre-concentration, and extraction of the analytes, aiming to provide a more accessible and affordable breast cancer patient-monitoring technology. The unique physicochemical properties of MOFs, such as high porosity and surface area, combined with PAN's stability and low density, are leveraged to improve SPE efficiency. The study meticulously examines the interactions of these MOFs with the analytes under various conditions, including elution solvents and protein precipitators. Results reveal that ZIF-8/PAN composites outperform CuBTC/PAN and PAN alone, especially when methanol is used as the protein precipitator. This superior performance is attributed to the physicochemical compatibility between the analytes' properties, like solubility and polarity, and the MOFs' structural features, including pore flexibility, active site availability, surface polarity, and surface area. The findings underscore MOFs' potential in SPE applications and provide valuable insights into the selectivity and sensitivity of different MOFs towards specific analytes, advancing more efficient targeted extraction methods in biomedical analysis.

Determination of Tetracycline Antibiotics in Milk by Solid-Phase Extraction Using a Coordination Polymer Based on Cobalt Trimesinate as a Sorbent

The coordination polymer was obtained based on cobalt trimesinate. It was characterized by elemental analysis, IR spectroscopy, X-ray diffraction analysis and scanning electron microscopy. The polymer was studied as a sorbent for solid-phase extraction of tetracycline antibiotics. Cobalt trimesinate had a high adsorption capacity (400 mg/g). Antibiotic adsorption followed the pseudo-second-order kinetic model and the Freundlich isotherm model. The process proceeded spontaneously, as indicated by the calculated thermodynamic parameters. The resulting coordination polymer has good stability and recyclability. The possibility of using cobalt trimesinate for the determination of tetracycline in various milk samples was investigated. This work holds great promise for the development and application of a cobalt trimesinate-based coordination polymer for use in sample preparation to replace the time-consuming vacuum evaporation procedure with a relatively simple solid-phase extraction procedure.

An efficient deep eutectic magnetic nano gel for rapid ultrasound-assisted dispersive µ-solid phase extraction of residue of tetracyclines in food samples

In the present study, a magnetic nano gel as the sorbent which is the combination of octatonic acid: cumarin as eutectic solvent and Fe3O4@SiO2 was introduced as the sorbent in ultrasound-assisted dispersive µ-solid phase extraction process coupled with high performance liquid chromatography with photo diode array detector for simultaneous separation and determination of tetracyclines residues in food samples. FT-IR, SEM, VSM were used for the characterization of the synthetized magnetic nano gel. Under obtained optimum conditions, the obtained linear ranges were 1.5-500 (µg L-1), 2.5-750 (µg L-1), 2-750 (µg L-1), and 2.5-500 (µg L-1) for tetracycline, oxytetracycline, chlortetracycline, and doxycycline, respectively. Moreover, the below level of quantification (BLQ) (based on S/N = 3) of 0.47 µg L-1, 0.11 µg L-1, 0.85 µg L-1, 0.66 µg L-1, 0.81 µg L-1 and the limit of quantification (based on S/N = 10) of 1.61, 2.74, 2.23 (µg L-1), and 2.66 were achieved for tetracycline, oxytetracycline, chlortetracycline, and doxycycline, respectively. The intra-day and inter-day precision (%) of the procedure were less than 3.2 and 3.8, respectively. The recoveries over 95% confirmed high sufficiency of the proposed method for application in complex matrices such as honey, milk, and egg.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05798-w.

Metal-Organic Frameworks in Bioanalysis: Extraction of Small Organic Molecules

The quantitative determination of xenobiotic compounds, as well as biotics in biological matrices, is generally described with the term bioanalysis. Due to the complexity of biofluids, in combination with the low concentration of the small molecules, their determination in biological matrices is a challenging procedure. Apart from the conventional solid-phase extraction, liquid-liquid extraction, protein precipitation, and direct injection approaches, nowadays, a plethora of microextraction and miniaturized extraction techniques have been reported. Furthermore, the development and evaluation of novel extraction adsorbents for sample preparation has become a popular research field. Metal-organic frameworks (MOFs) are novel materials composed of metal ions or clusters in coordination with organic linkers. Unequivocally, MOFs are gaining more and more attention in analytical chemistry due to their superior properties, including high surface area and tunability of pore size and functionality. This review discusses the utilization of MOFs in the sample preparation of biological samples for the green extraction of small organic molecules. Their common preparation and characterization strategies are discussed, while emphasis is given to their applications for green sample preparation.

Green bioanalytical sample preparation: fabric phase sorptive extraction

Fabric phase sorptive extraction (FPSE) is a recently introduced sample preparation technique that has attracted substantial interest of the scientific community dealing with bioanalysis. This technique is based on a permeable and flexible substrate made of fabric, coated with a sol-gel organic-inorganic sorbent. Among the benefits of FPSE are its tunable selectivity, adjustable porosity, minimized sample preparation workflow, substantially reduced organic solvent consumption, rapid extraction kinetics and superior extraction efficiency, many of which are well-known criteria for Green Analytical Chemistry. As such, FPSE has established itself as a leading green sample preparation technology of 21st century. In this review, we discuss the principal steps for the development of an FPSE method, the main method optimization strategies, as well as the applications of FPSE in bioanalysis for the extraction of a wide range of analytes (e.g., estrogens, benzodiazepines, androgens and progestogens, penicillins, anti-inflammatory drugs, parabens etc.).

Monitoring of priority pollutants chlorophenols in water and milk by headspace solid-phase microextraction based on electrospun polycaprolactam nanofibers decorated with cadmium oxide-carbon nanotubes

Priority pollutants chlorophenols are broadly used chemicals that are persistent in the environment and causing serious human health hazards. The current study introduces a novel adsorbent for the extraction of chlorophenols from river water, surface water, and milk by headspace solid-phase microextraction coupled with gas chromatography. The adsorbent composite was prepared by blending polycaprolactam (nylon-6) mat and newly synthesized carbon nanotubes decorated with cadmium oxide nanoparticles followed by electrospinning technique to produce based nanofiber. The proposed nanofiber was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction techniques. The main parameters that affect extraction efficiency, including ionic strength, extraction time, desorption time, and extraction temperature, were investigated and optimized. The linear range was 0.05-5 ng/mL; the limits of detection (signal/noise=3) were 0.02-0.04 ng/mL. The relative recoveries for real samples (river water, surface water, and milk) were in the range of 84-114%.

Integrated in-syringe magnetic sheet solid-phase extraction and dispersive liquid-liquid microextraction for determination of aflatoxins in fresh and moldy breads

BACKGROUND

Magnetic three-dimensional graphene-based nanoadsorbents have unique characteristics such as large surface area, good thermal and chemical stability, and high adsorption capacity that make them efficient materials in sorbent-based extraction techniques. In this study, four aflatoxins (AFs) were analyzed in bread samples using magnetic three-dimensional graphene as the adsorbent phase in dispersive micro solid-phase extraction.

RESULTS AND CONCLUSIONS

In-syringe magnetic sheet solid-phase extraction based on magnetic three-dimensional graphene in tandem with dispersive liquid-liquid microextraction was used for the extraction and preconcentration of the target AFs. The effect of significant parameters of the method was investigated and the optimum conditions were determined as follows: adsorbent dosage, 20 mg; desorption/disperser solvent (methanol) volume, 700 μL; desorption solvent flow rate, 0.7 mL min^-1 ; pH, neutral; salt (NaCl) concentration, 10% (w/v); extraction solvent (chloroform) volume, 250 μL; and centrifugation rate (and time), 4000 rpm (5 min). The limits of detection and quantification were in the ranges 0.043-0.083 and 0.14-0.28 μg kg^-1 , respectively. The extraction method was followed by the HPLC technique with fluorescence detection and applied to the determination of the AFs in four different Iranian fresh and moldy bread samples. The relative recoveries were in the range 84-107% with relative standard deviations of 3.9-8.6%. © 2019 Society of Chemical Industry.