Dispersive micro-solid phase extraction of bisphenol A from milk using magnetic nylon 6 composite and its final determination by HPLC-UV

Microfluidic analytical devices based on deep eutectic solvent-hydrogel thin film electromembrane extraction of bisphenol A from thermal paper, mineral, and tap water samples, and greenness assessment by AGREEprep tools

A microfluidic analytical device based on deep eutectic solvent-hydrogel thin film electromembrane extraction was presented for the determination of bisphenol A in thermal paper, mineral, and tap water samples. The microfluidic device is constructed from two polymethyl methacrylate sections, each featuring two engraved channels. These channels serve dual purposes: one as a conduit for the sample solution and the other as a compartment for the acceptor phase. A deep eutectic ionic liquid, employed as a plasticizer, was blended into an agarose polysaccharide to create a stable, conductive, and flexible membrane. This eco-friendly membrane is positioned between the device's two sections to segregate the channels. Platinum electrodes are installed at the base of these channels and connected to a power source that facilitates the electromigration of ionized analytes across the porous agarose membrane. This new configuration enables efficient and consistent extractions using minimal sample volumes. The parameters influencing the microfluidic determination of bisphenol A were meticulously optimized. Under these conditions, the calibration curve demonstrated linearity from 0.0001 to 200 mg L-1 with a coefficient of determination (R2) exceeding 0.9974. The relative standard deviations (RSDs %) for the extraction and quantification of bisphenol A were 3.2%.

Trace analysis of 20 antihistamines in milk by ultrahigh performance liquid chromatography coupled with high field quadrupole orbitrap high resolution mass spectrometry followed dispersive micro solid phase extraction

Ultrahigh-performance liquid chromatography coupled with high-field quadrupole Orbitrap high resolution mass spectrometry was used for the separation and determination of 20 antihistamines, and a dispersive micro solid-phase extraction procedure using high-performance absorbing material was developed as a sample preparation strategy for extracting 20 antihistamines from milk. Instrument conditions and key parameters influencing extraction efficiency were investigated to obtain an optimized method. The limit of detection for 20 antihistamines in milk using this method is 0.05 µg/L to 1.0 µg/L. Recoveries are between 80.7 % and 108.3 %, and the relative standard deviation is less than 15 %. It is suitable for confirmatory monitoring and quantitative analysis of 20 antihistamines in milk. The results show that antihistamines in milk may be noteworthy issues for human health and environmental pollution.

Unravelling the potential of magnetic nanoparticles: a comprehensive review of design and applications in analytical chemistry

The study of nanoparticles has emerged as a prominent research field, offering a wide range of applications across various disciplines. With their unique physical and chemical properties within the size range of 1-100 nm, nanoparticles have garnered significant attention. Among them, magnetic nanoparticles (MNPs) exemplify promising super-magnetic characteristics, especially in the 10-20 nm size range, making them ideal for swift responses to applied magnetic fields. In this comprehensive review, we focus on MNPs suitable for analytical purposes. We investigate and classify them based on their analytical applications, synthesis routes, and overall utility, providing a detailed literature summary. By exploring a diverse range of MNPs, this review offers valuable insights into their potential application in various analytical scenarios.

Electrospun of functionalized mesoporous UiO-66 as the selective coating of solid phase microextraction Arrow for the determination of nine alkylphenols

A solid-phase microextraction (SPME) Arrow and high-performance liquid chromatography-UV detector (HPLC-UV, detection at 225 nm) based method was developed for the selective determination of nine alkylphenols (APs) in milk. The functionalized mesoporous UiO-66 (4-meso-UiO-66) was utilized as the new coating material, which was synthesized by post-modification of pore-expanded UiO-66-NH2 by an esterification reaction with 4-pentylbenzoic acid. It was fully characterized by X-ray photoelectron spectroscopy (XPS), fourier transformation infrared spectrometry, nitrogen sorption-desorption test, scanning electron microscopy, transmission electron microscopy, and X-ray diffractometer. The characterization results showed the ester groups and benzene rings were introduced into the 4-meso-UiO-66, and the mesoporous structure was predominant in the 4-meso-UiO-66. The extraction mechanism of 4-meso-UiO-66 to APs is the synergistic effect of Zr-O electrostatic interaction and the size exclusion effect resulting from XPS, selectivity test, and nitrogen sorption-desorption test. The electrospinning technique was utilized to fabricate the 4-meso-UiO-66 coated SPME Arrow and polyacrylonitrile (PAN) was used as the adhesive. The mass rate of 4-meso-UiO-66 to PAN and the electrospinning time were evaluated. The extraction and desorption parameters were also studied. The linear range of this method was 0.2-1000 μg L-1 with a coefficient of determination greater than 0.9989 under the optimal conditions. The detection limits were 0.05-1 μg L-1, the inter-day and intra-day precision (RSD) were 2.8-11.5%, and the recovery was 83.6%-112%. The reusability study showed that the extraction performance of this new SPME Arrow could be maintained after 80 adsorption-desorption cycles. This method showed excellent applicability for the selective determination of APs in milk.

dl-carnitine-based green hydrophobic deep eutectic solvent for the enrichment of bisphenol A in mineral water based on ultrasound-assisted liquid-phase microextraction

A powerful pretreatment technique, ultrasound-assisted dispersive liquid-phase microextraction (USA-DLPME) based on dl-Carnitine-based deep eutectic solvent (DES), has been developed to efficiently enrichment of bisphenol A from mineral water samples. The DES-based USA-DLPME technique demonstrated superior extraction efficiency for bisphenol A compared to established organic solvent-based liquid-liquid extraction techniques. The conditions for the extraction of bisphenol A were predicted using the response surface methodology. The effects of pH (A: 2-10), NaCl concentration (B: 0.2-1.0%w/v), DES volume (C: 30-150 μL), and sonication time (D: 1-5 min) were examined using an experimental design. The extraction recovery of Bisphenol A under optimum conditions was achieved at 99.897% (A = 8, B = 0.4%w/v, C = 120 μL, and D = 5 min). Under these conditions, a wide linear range of 1-600 ng mL-1, an enrichment factor of 81.52, a low detection limit of 0.26 ng mL-1 and a limit of quantification of 0.87 ng mL-1 were obtained. Lastly, the proposed technique was used to accurately and reliably identify bisphenol A in various mineral water samples, yielding relative recoveries in the 92-96% range with RSD≤3%. These findings imply that DESs can be widely and successfully used to extract chemicals from actual materials. DESs are a class of innovative green solvents with the potential to replace organic solvents.

Determination of Parabens and Phenolic Compounds in Dairy Products through the Use of a Two-Step Continuous SPE System Including an Enhanced Matrix Removal Sorbent in Combination with UHPLC-MS/MS

Dairy products can be contaminated by parabens and phenolic compounds from a vast variety of sources, such as packaging and manufacturing processes, or livestock through feed and environmental water. A two-step continuous solid-phase extraction (SPE) and purification methodology was developed here for the determination of both types of compounds. In the first step, a sample extract is passed in sequence through an EMR-lipid sorbent and an Oasis PRiME HBL sorbent to remove fat and preconcentrate the analytes for subsequent detection and quantification by UHPLC-MS/MS. This method enabled the determination of 28 parabens and phenolic contaminant with excellent recovery (91-105%) thanks to the SPE sorbent combination used. The proposed method was validated through the determination of the target compounds, and was found to provide low detection limits (1-20 ng/kg) with only slight matrix effects (0-10%). It was used to analyse 32 different samples of dairy products with different packaging materials. Bisphenol A and bisphenol Z were the two phenolic compounds quantified in the largest number of samples, at concentrations over the range of 24-580 ng/kg, which did not exceed the limit set by European regulations. On the other hand, ethylparaben was the paraben found at the highest levels (33-470 ng/kg).

Solid phase extraction with rotating cigarette filter for determination of bisphenol A in source and drinking water: computational and analytical studies

An ultrasound assisted solid phase extraction method using rotating cigarette filter is developed herein to preconcentrate and determine trace amount of bisphenol in source and drinking water. Qualitative and quantitative measurements were performed using high-performance liquid chromatography coupled with ultra violet detector. Sorbent-analyte interactions were thoroughly investigated computationally and experimentally using molecular dynamics simulations; and attenuated total reflectance Fourier transform infrared spectroscopy, and Raman spectroscopy, respectively. Various extraction parameters were investigated and optimized. Under the optimal conditions, the results were linear in a low scale range of 0.01-55 ng/mL with correlation coefficient of 0.9941 and a low limit of detection (0.04 ng/mL, signal/noise = 3:1). A good precision (intra-day relative standard deviation ≤ 6.05%, inter-day relative standard deviation ≤ 7.12%) and recovery (intra-day ≥ 98.41%, inter-day ≥ 98.04%)) are obtained. Finally, the proposed solid phase extraction method offered a low cost, simple, fast, and sensitive analytical method to determine trace amount of bisphenol A in source and drinking water samples with chromatographic detection.

Validation and Use of an Accurate, Sensitive Method for Sample Preparation and Gas Chromatography-Mass Spectrometry Determination of Different Endocrine-Disrupting Chemicals in Dairy Products

Endocrine disrupting chemicals (EDCs) are exogenous substances capable of altering the human hormone system and causing various diseases such as infertility and cancer as a result. In this work, a method for determining twenty-three different EDCs including parabens, alkylphenols, phenylphenols, organophosphorus pesticides, bisphenol A and triclosan in dairy products was developed. Samples are conditioned by addition of acetonitrile containing 1% formic acid, centrifugation and clean-up of the extract by continuous solid-phase extraction. EDCs in the extract are derivatised by heating in a microwave oven and quantified by gas chromatography-mass spectrometry. The proposed method features good limits of detection (6-40 ng/kg) and precision (relative standard deviation < 7.6%); also, it is scarcely subject to matrix effects (1-20%). EDC recoveries from spiked samples ranged from 80 to 108%. The method was used to analyse a total of 33 samples of dairy products including cow, sheep and goat milk, yoghourt, milkshakes, cheese, cream, butter and custard. Bisphenol A was the individual contaminant detected in the greatest number of samples, at concentrations from 180 to 4800 ng/kg. 2-Phenylphenol and ethylparaben were found in more than one-half, at concentrations over the range 130-3500 and 89-4300 ng/kg, respectively. In contrast, alkylphenols, organophosphorus pesticides and triclosan were detected in none.

Surfactant-coupled titanium dioxide coated iron-aluminium mixed metal hydroxide for magnetic solid phase extraction of bisphenols in carbonated beverages

In this work, the magnetic sorbents based on different surfactant-coupled titanium dioxide coated iron-aluminium mixed metal hydroxide were investigated as sorbent for extraction of bisphenol compounds. The structure, morphology, and magnetic property of the synthesized sorbents were investigated. The cetyltrimethylammonium bromide-titanium dioxide coated iron-aluminium mixed metal hydroxide (Fe-Al MMH@TiO2-CTAB) exhibited excellent extraction performance toward bisphenols and was selected as the sorbent for development of magnetic solid phase extraction (MSPE) method. The entire MSPE process was optimized, and the extract was analyzed by high performance liquid chromatography with photodiode array detector. The method provided wide linear calibration ranges for bisphenols between 0.3-6000 μg L-1 with maximum enrichment factors of 280. The limits of detection and limits of quantification were in the ranges of 0.08-0.3 and 0.3-1.0 μg L-1, respectively. The proposed MSPE method was tested for determination of bisphenols in carbonated beverages. The studied carbonated beverages were mostly free of bisphenol contamination; however, BPS, BPA and BPB were detected in samples taken from defective cans. The relative recoveries ranging of 80.2-118.9% were obtained. The as-prepared Fe-Al MMH@TiO2-CTAB sorbent provided high sorption capacities in the range of 2215-2451 mg kg-1 and could be a promising material for bisphenols in beverage samples.

Simultaneous adsorption and determination of bisphenol compounds in water medium with a Zr(IV)-based metal-organic framework

A chemically stable Zr(IV)-based metal-organic framework (BUT-17) has been explored for simultaneous adsorption and determination of bisphenol compounds (BPs) in aqueous medium. The prepared BUT-17 possesses a large surface area (2936 m² g^-1) and excellent fluorescent performance. An adsorption capacity of 111 mg g^-1 for bisphenol A (BPA) with a rapid adsorption rate (1.76 g mg^-1 min^-1) is achieved by BUT-17. The excellent adsorption performance could be attributed to the hydrogen bond interaction between BPs and BUT-17. Furthermore, the fluorescent intensity of BUT-17 was quenched up to 92% due to the formation of complexes between BPs and BUT-17. Thus, a BUT-17-based fluorescent sensing method for the rapid determination of BPs has been established with the limit of detection of 10.0 ng mL^-1 for BPA and a linear range from 2.0 to 23.0 μg mL^-1. These results indicate that as an outstanding multifunctional platform, BUT-17 is promising for the simultaneous removal and determination of BPs in water medium. Simultaneous removal and detection of BPs with BUT-17.

Review: Microextraction Technique Based New Trends in Food Analysis

Food chemistry is the study and classification of the quality and origin of foods. The identification of definite biomarkers and the determination of residue contaminants such as toxins, pesticides, metals, human and veterinary drugs, which are a very common source of food-borne diseases. The food analysis is continuously demanding the improvement of more robust, sensitive, highly efficient, and economically beneficial analytical approaches to promise the traceability, safety, and quality of foods in the acquiescence with the consumers and legislation demands. The traditional methods have been used at the starting of the 20th century based on wet chemical methods. Now it existing the powerful analytical techniques used in food analysis and safety. This development has led to substantial enhancements in the analytical accuracy, precision, sensitivity, selectivity, thereby mounting the applied range of food applications. In the present decade, microextraction (micro-scale extraction) pays more attention due to its futures such as low consumption of solvent and sample, throughput analysis easy to operate, greener, robotics, and miniaturization, different adsorbents have been used in the microextraction process with unique nature recognized with wide range applications.

Determination of bisphenol A: Old problem, recent creative solutions based on novel materials

Bisphenol A is a synthetic compound widely used in industry, in the production of polycarbonate, epoxy resins, and thermal paper, among others. Its annual production is estimated at millions of tons per year, demonstrating its importance. Despite its wide application in various everyday products, once in the environment (due to its disposal or leaching), it has high toxicity to humans and animal life, and this problem has been well known for years. Given this problem, many researchers seek alternatives for its monitoring in matrices such as natural water, waste, food, and biological matrices. For this, new advanced materials have been developed, characterized, and applied in creative ways for the preparation of samples for the determination of bisphenol A. This article aims to present some of these important and recent applications, describing the use of molecularly imprinted polymers, metal and covalent organic frameworks, ionic liquids and magnetic ionic liquids, and deep eutectic solvents as creative solutions in sample preparation for the long-standing problem of bisphenol A determination.

Paper-based sorptive phases for microextraction and sensing

The simplification of the analytical procedures, including cost-effective materials and detectors, is a current research trend. In this context, paper has been identified as a useful material thanks to its low price and high availability in different compositions (office, filter, chromatographic). Its porosity, flexibility, and planar geometry permit the design of flow-through devices compatible with most instrumental techniques. This article provides a general overview of the potential of paper, as substrate, on the simplification of analytical chemistry methodologies. The design of paper-based sorptive phases is considered in-depth, and the different functionalization strategies are described. Considering our experience in sample preparation, special attention has been paid to the use of these phases under the classical microextraction-analysis workflow, which usually includes a chromatographic separation of the analytes before their determination. However, the interest of these materials extends beyond this field as they can be easily implemented into spectroscopic and electrochemical sensors. Finally, the direct analysis of paper substrates in mass spectrometry, in the so-called paper-spray technique is also discussed. This review is more focused on presenting ideas rather than the description of specific applications to draw a general picture of the potential of these materials.

Ion-Trap Mass Spectrometric Analysis of Bisphenol A Interactions With Titanium Dioxide Nanoparticles and Milk Proteins

Quantitative analysis of endocrine-disrupting molecules such as bisphenol A (BPA) in freshwater to determine their widespread occurrence in environmental resources has been challenged by various adsorption and desorption processes. In this work, ion trap mass spectrometry (ITMS) analysis of BPA was aimed at studying its molecular interactions with titanium dioxide (TiO2) nanoparticles and milk whey proteins. Addition of sodium formate prevented TiO2 nanoparticles from sedimentation while enhancing the electrospray ionization (ESI) efficiency to produce an abundance of [BPA + Na]+ ions at m/z 251.0. More importantly, the ESI-ITMS instrument could operate properly during a direct infusion of nanoparticles up to 500 μg/mL without clogging the intake capillary. Milk protein adsorption of BPA could decrease the [BPA + Na]+ peak intensity significantly unless the proteins were partially removed by curdling to produce whey, which allowed BPA desorption during ESI for quantitative analysis by ITMS.

Magnetic Graphene Oxide Composite for the Microextraction and Determination of Benzophenones in Water Samples

Magnetite nanoparticles (Fe₃O₄) functionalized with graphene oxide (GO) have been synthesized through a silanization process of the magnetic nanoparticles with tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane and further coupling of GO. The synthesized nanomaterials have been characterized by several techniques, such as transmission electron microscopy (TEM), and infrared and Raman spectroscopy, which enabled the evaluation of the different steps of the functionalization process. The hybrid nanomaterial has been employed for the extraction of five benzophenones (benzophenone-1, benzophenone-3, 4-hydroxybenzophenone, benzophenone-6 and benzophenone-8) in aqueous samples by dispersive micro-solid phase extraction, combining the magnetic properties of magnetite nanoparticles with the excellent sorption capacity of graphene oxide via hydrophobic interactions with the analytes. The subsequent separation and quantification of the analytes was performed by liquid chromatography with tandem mass spectrometric detection, achieving limits of detection (LODs) in the range 2.5 to 8.2 μg·L^-1, with relative standard deviations ranging from 1.3-9.8% and relative recovering in the range 86 to 105%. Positive swimming pool water samples analysed following the developed method revealed the presence of benzophenones in from 14.3 to 39 μg·L^-1.

Parallel sample processing using dispersive INtip micro-purification on programmable multichannel pipettes

Automation gives researchers the ability to process and screen orders of magnitude higher numbers of samples than manual experimentation. Current biomacromolecule separation methodologies suffer from necessary manual intervention, making their translation to high-throughput automation difficult. Herein, we present the first characterization of biomacromolecule affinity purification via dispersive solid-phase extraction in a pipette tip (INtip). We use commercially available resin and compare efficiency with batch and spin column methodologies. Moreover, we measure the kinetics of binding and evaluate resin binding capacities. INtip technology is effective on, and scalable for, an automated platform (INTEGRA ASSIST). The results suggest that high-throughput biomolecular workflows will benefit from the integration of INtip separations.

Fabrication of glucose-derived carbon-decorated magnetic microspheres for extraction of bisphenols from water and tea drinks

Glucose-derived carbon-decorated magnetic microspheres were synthesized by an easy hydrothermal carbonization method and used as a high-efficiency adsorbent to extract bisphenols in water and tea drinks. The as-prepared carbon-decorated magnetic microspheres had a well-defined core-shell structure with a shell thickness of about 5 nm. The microspheres possessed high saturation magnetization at 60.8 emu/g and excellent chemical stability in aqueous solution. The experimental parameters affecting the extraction efficiency, including extraction time, pH, adsorbent dosage, desorption solvents, desorption time, and solution volume were evaluated. Electrostatic and π-π interactions were the major driving forces during extraction. Overall, a new magnetic solid-phase extraction method of determining bisphenols was developed on the basis of as-prepared magnetic microspheres. The method had a wide linear range, low limits of detection (0.03-0.10 µg/L), and high recoveries (85.4-104.6%).

Efficiency comparison of nylon-6-based solid-phase and stir bar sorptive extractors for carbamazepine extraction

Aim: Two approaches based on molecularly imprinted polymers-stir bar sorptive extraction (MIP-SBSE) and -magnetic solid-phase extraction (MIP-MSPE) have been used for extraction of carbamazepine (CBZ) from serum samples. Methodology: In MSPE and SBSE, development was achieved by employing a polycaprolactam coating. The Cecil® chromatographic system equipped with a UV-Vis detector was used for analytical determination of CBZ. Results: The linearity of calibration curves was in the concentration ranges of 0.2–12 and 0.05–12 μg ml-1 for MIP-SBSE and MIP-MSPE, respectively. Conclusion: MIP-MSPE was selected in preference to MIP-SBSE since lower limits of detection were achievable using MIP-MSPE method. The CBZ-MIP-MSPE-HPLC-UV method was successfully applied to CBZ determination in real serum samples of patients receiving CBZ.

Magnetic Polyamide Nanocomposites for the Microextraction of Benzophenones from Water Samples

In this article, the influence of the monomers on the extraction efficiency and the effect of the addition of surfactants during the synthesis have also been considered. The sorption capacity of the resulting nanocomposites has been evaluated, in the dispersive micro-solid phase extraction format, by determining that of six benzophenones in water using ultra performance liquid chromatography (UPLC) combined with photodiode array detection. Under the optimum conditions, the limits of detection were in the range of 0.5–4.3 ng/mL and the repeatability, expressed as the relative standard deviation (RSD), varied between 1.5% and 5.6%. The proposed method has been applied for the analysis of real water samples, providing relative recoveries in the interval of 84–105%

A Phenolphthalein-Dummy Template Molecularly Imprinted Polymer for Highly Selective Extraction and Clean-Up of Bisphenol A in Complex Biological, Environmental and Food Samples

A molecularly imprinted polymer (MIP) for highly selective solid-phase extraction (SPE) of bisphenol A (BPA) was prepared using phenolphthalein (PP) as the novel dummy template by bulk polymerization. A particle diameter distribution of 40⁻60 μm, a specific surface area of 359.8 m²·g-1, and a total pore volume of 0.730 cm³·g-1 for the prepared PP-imprinted polymer (PPMIP) were obtained. Good selectivity and specific adsorption capacity for BPA of the prepared PPMIP were also demonstrated by the chromatographic evaluation and sorption experiments. The PPMIP as a SPE sorbent was evaluated for the selective extraction and clean-up of BPA from complex biological, environmental, and food samples. Meanwhile, an accurate and sensitive analytical method based on the PPMIP-SPE purification procedure coupled with high performance liquid chromatography-diode array detector (HPLC-DAD) detection has been successfully developed for the rapid determination of BPA from these samples, with detection limits of 1.3 ng·mL-1 for bovine serum and milk, 2.6 ng·mL-1 for human urine and edible oil, 5.2 ng·mL-1 for soybean sauce, and 1.3 ng·g-1 for sediment. The BPA recoveries at two different spiking levels were in the range of 82.1⁻106.9%, with relative standard deviation (RSD) values below 7.7%.

Dispersive Solid Phase Extraction for the Analysis of Veterinary Drugs Applied to Food Samples: A Review

To achieve analytical success, it is necessary to develop thorough clean-up procedures to extract analytes from the matrix. Dispersive solid phase extraction (DSPE) has been used as a pretreatment technique for the analysis of several compounds. This technique is based on the dispersion of a solid sorbent in liquid samples in the extraction isolation and clean-up of different analytes from complex matrices. DSPE has found a wide range of applications in several fields, and it is considered to be a selective, robust, and versatile technique. The applications of dispersive techniques in the analysis of veterinary drugs in different matrices involve magnetic sorbents, molecularly imprinted polymers, carbon-based nanomaterials, and the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method. Techniques based on DSPE permit minimization of additional steps such as precipitation, centrifugation, and filtration, which decreases the manipulation of the sample. In this review, we describe the main procedures used for synthesis, characterization, and application of this pretreatment technique and how it has been applied to food analysis.