Development of tetraethylene pentamine functionalized multi-wall carbon nanotubes as a new adsorbent in a syringe system for removal of bisphenol A by using multivariate optimization techniques

Ultrasonic synthesis of magnetic covalent organic frameworks and application magnetic solid phase extraction for rapid adsorption of trace bisphenols in food samples

A simple ultrasonic synthesis strategy was developed for a novel magnetic covalent organic framework. Firstly, the Fe3O4 nanoparticles were encapsulated by imine-type COF, which generated by the Schiff reaction of 4,4',4''-(1,3,5-Triazine-2,4,6-triyl)-trianiline (TAPT) and tris(4-formylphenyl)-amine (TFPA) using ultrasonic synthesis method within 2 h. The synthesised nanocomposites showed a sizeable specific surface area, and high adsorption capacity. A fast, sensitive MSPE method with Fe3O4@TAPT-TFPA-COF as adsorbent for analysing bisphenol compounds was developed. This method's advantages were simple operation, short extraction time, and avoidance of the use of centrifugal equipment. The method validation indicate that this method exhibited superior linearity, and detection limits range between 0.33 and 0.60 μg L-1. The recoveries of BPs ranged from 74.7 % to 107.0 %, with relative standard deviations of less than 3.8 % in water, milk, vinegar, and soy sauce samples. The proposed method was successfully applied for extracting BPs in food samples.

Statistical physics modeling study of an environmentally friendly and efficient adsorbent derived from the brown macroalgae Bifurcaria bifurcata for the removal of Bisphenol A

The brown macroalgae Bifurcaria bifurcata was valued and used to develop a carbonaceous material activated by H2SO4 (AC-BB@H2SO4), with the goal of assessing its adsorption ability against Bisphenol A (BPA). During the adsorption experiments, the effects of the adsorbent dose, solution pH, and contact time were examined, and the results were m = 0.4 g/L, pH = 8.3, and t = 120 min, with an elimination yield of 91.6 %. With comparatively high R2 values, the pseudo-second-order kinetic model perfectly fitted the experimental data. Langmuir's model was found to be the best appropriate for describing the adsorption equilibrium of BPA on AC-BB@H2SO4. The thermodynamic findings show that BPA adsorption on AC-BB@H2SO4 was spontaneous, favorable, and endothermic in nature. Even after six cycles of reuse, regeneration testing demonstrated that our adsorbent could eliminate BPA by >50 %. The BPA adsorption mechanism's statistical physics control parameters were determined and analyzed. BPA's adsorption energies were <40 kJ/mol, indicating that the interactions between BPA and AC-BB@H2SO4 were governed by physical forces (i.e., hydrogen bonding and van der Waals and electrostatic interactions). All of these intriguing findings indicate that our carbonaceous material might have direct ramifications in the field of wastewater treatment, notably for the clearance of BPA, which is difficult to biodegrade.

An integrated approach to remove endocrine-disrupting chemicals bisphenol and its analogues from the aqueous environment: a review

Bisphenol A (BPA) is a well-known endocrine-disrupting chemical (EDC) used as a plastic enhancer in producing polycarbonate resins to manufacture hard plastics. Due to strict limitations on the manufacturing and utilization of BPA, several bisphenol substitutes, bisphenol F (BPF), bisphenol S (BPS), and bisphenol AF (BPAF), have been developed to replace it in various applications. Because of their widespread use in food containers, infant bottles, and reusable water bottles, bisphenols (BPs) have been identified in different environmental circumstances, including drinking water, seawater, industrial effluent, and endocrine systems such as human blood, urine, and breast milk. However, locating and analyzing them in different conditions has proven to be challenging. Therefore, there is a need to reduce the prevalence of BPs in the environment. The significance of advanced treatment options for treating and eliminating BPA and its alternatives from water bodies are reviewed. Also, the research gaps and future scopes are discussed in this review article. According to the literature survey, adsorption and photocatalytic degradation provide synergistic benefits for environmental challenges because of their substantial adsorption Q5 capacity, high oxidation capability, and low cost compared to alternative individual treatment options.

Analysis of microsamples by miniaturized magnetic-based pipette tip microextraction: determination of free cortisol in serum and urine from very low birth weight preterm newborns

Miniaturized magnetic-based pipette tip microextraction is presented as a sample preparation approach for microsamples. It involves quick dispersion of a diminutive amount of a magnetic sorbent material in a low-volume sample (10 μL) to entrap the target analytes. Next, the dispersion is aspirated using a (semi)automatic pipette through a pipette tip with a small cubic neodymium magnet inside, which retrieves the magnetic sorbent containing the analytes. After discarding the rest of the sample, the sorbent is properly rinsed by aspirating/dispensing deionized water, and then, the analytes are eluted by aspirating/dispensing an appropriate solvent. This approach was employed for the determination of free cortisol in serum and urine from very low birth weight preterm newborns, a vulnerable patient group who present low availability for sampling biological fluids. A magnetic immunosorbent made of a cortisol antibody was employed for the selective extraction, followed by liquid chromatography-tandem mass spectrometry. Good analytical features were obtained, such as limits of detection and quantification of 0.08 and 0.27 ng mL^-1, respectively, linearity up to 50 ng mL^-1 (R² > 0.999), RSD values under 15% and relative recoveries between 91 and 111%. The cross-reactivity with other glucocorticoids (i.e., cortisone and prednisolone) was evaluated to show the selectivity of the extraction. Finally, the method applicability was demonstrated towards the determination of free cortisol in the serum and urine samples from low birth weight preterm newborns.

Application of a modified MWCNT-based d-µSPE procedure for determination of bisphenols in soft drinks

Herein, a facile dispersive micro-solid phase extraction (d-µSPE) procedure using carboxylated multi-walled carbon nanotubes modified with silver nanoparticles (Ag/MWCNTs-COOH) was successfully developed for the adsorption and subsequent determination of low levels of two well-known contaminants, namely bisphenol A and S (BPA and BPS) in water and soft drink samples. The detection and measurement of the above-mentioned compounds were performed by HPLC-UV instrument. The applied d-µSPE procedure has several advantages such as rapidity, high degree of sensitivity, precision and efficiency. A combination of polar/non-polar interactions seems to play a key role in the adsorption process. Under the optimized conditions, the calibration curves were linear over the concentration range of 1-500 µg/L for the both targets. The practical limit of quantifications (LOQ) for the both analytes were determined to be 1.0 µg/L. The average relative recoveries obtained from the fortified samples varied between 92 and 110% with the relative standard deviations (RSD%) of 2.9-9.5%.

Novel solid-phase microextraction fiber coatings: A review

The materials used for the fabrication of solid-phase microextraction fiber coatings in the past five years are summarized in the current review, including carbon, metal-organic frameworks, covalent organic frameworks, aerogel, polymer, ionic liquids/poly (ionic liquids), metal oxides, and natural materials. The preparation approaches of different coatings, such as sol-gel technique, in-situ growth, electrodeposition, and glue methods, are briefly reviewed together with the evolution of the supporting substrates. In addition, the limitations of the current coatings and the future development directions of solid-phase microextraction are presented.

A new approach for microextraction of trace albendazole sulfoxide drug from the samples of human plasma and urine, and water by the molecularly imprinted polymer nanoparticles combined with HPLC

In this research study, a method of dispersive-micro-solid phase extraction (D-µ-SPE) combined with molecularly imprinted polymer nanoparticles (MIP-NPs) with HPLC-UV was developed for the fast and selective detection of the trace amount of albendazole sulfoxide (ABZSO) in the biological samples. To investigate the effective factors on ABZSO microextraction by the method, central composite design (CCD) was utilized, and the optimum conditions for ABZSO microextraction were sample pH of 8.0, MIP-mass of 15 mg, sonication time of 12 min, and eluent (methanol) volume of 0.25 mL. Under the obtained optimal extraction conditions, the value for the limit of detection (LOD) and limit of quantification (LOQ) was respectively showed to be 0.074 and 0.246 ng mL^-1. In addition, the calculated peak areas exhibited a linear relationship with the ABZSO concentration ranging from 0.4 to 4200 ng mL^-1. The analyses of the samples including human plasma and urine, and water were successfully performed by the usage of the D-µ-SPE method, which was a simple and sensitive technique and a suitable alternative for the analysis of ABZSO. In the analysis of ABZSO in various samples, the recoveries at various levels of ABZSO concentrations (50, 300, and 500 ng mL^-1) were in the range of 95.7-103.0 %, and the relative standard deviations (RSDs; n = 3) varied from 2.2 to 4.4%.

Application of the electropolymerized poly(3,4-ethylenedioxythiophene) sorbent for solid-phase microextraction of bisphenols

A new, simple, and effective procedure using poly(3,4-ethylenedioxythiophene)/lignosulfonate electropolymerized sorbent solid-phase microextraction (PEDOT/LS-SPME) combined with LC-MS/MS for determination of bisphenols in environmental water samples was developed. Various parameters influencing the performance of the analytical procedure including the type of sorbent, electropolymerization time, sorbent preconditioning time, extraction time, desorption (time and solvent), and sample pH were investigated and optimized. Under optimal conditions the proposed method allowed us to achieve good precision (n = 5) between 6.0 and 12.1%. The limits of detection were equal to 0.17 μg L-1 for BPA, 0.16 μg L-1 for BPF, 0.07 μg L-1 for BPE, 0.05 μg L-1 for BPB, and 0.027 μg L-1 for BPAF. The proposed method was successfully applied for the determination of bisphenols in aqueous environmental samples.

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.

Selection of the Activated Carbon Type for the Treatment of Landfill Leachate by Fenton-Adsorption Process

Sanitary landfill leachates usually have characteristics that depend on the region where they are generated and according to the age of the landfill, which is why a unique treatment for their sanitation has not been found. However, the adsorption preceded by the Fenton process has been proven to be highly efficient at removing contaminants. In this study, the adsorptive capacity of two types of activated carbon, granular and powdered, was analyzed to determine which was more efficient in the adsorption stage in the Fenton-adsorption process. Likewise, its behavior was analyzed using three isotherm models (Langmuir, Freundlich and Temkin), testing the raw leachate and the Fenton-treated one with both carbons. The adsorption that is carried out on the carbons is better adjusted to the Freundlich and Temkin models. It concludes that multilayers, through the physical adsorption, carry out the adsorption of pollutants on the surface of the carbons. The results show that, statistically, granular activated carbon is more efficient at removing chemical oxygen demand (COD), and powdered activated carbon removes color better. Finally, an adsorption column was designed for the Fenton-adsorption process that was able to remove 21.68 kgCOD/kg carbon. Removal efficiencies for color and COD were >99%.

Adsorptive removal of endocrine disrupting compounds from aqueous solutions using magnetic multi-wall carbon nanotubes modified with chitosan biopolymer based on response surface methodology: Functionalization, kinetics, and isotherms studies

Recently, the presence of endocrine disrupting compounds in the environment has emerged as a global and ubiquitous problem. In this study, a novel synthesis of magnetically carbon nanotube modified with biological polymeric was successfully prepared. The effect of different parameters on the Bisphenol A (BPA) adsorption was studied. A prediction model for BPA adsorption was extended based on the Central Composite Design. Also, the prepared biopolymeric nanotubes were characterized by FT-IR, XRD, TEM, FE-SEM. The surface morphology of nanocomposite was observed, increased carbon nano tube size, and the levels after surface deposition were completely covered by chitosan proteins. The results of our experiments showed that optimum adsorption conditions was achieved at t = 76 min, BPA concentration 6.5 mg/L, adsorbent dosage 1 g/L and pH = 6.2.The data obtained in this study followed the Langmuir isotherm model and the pseudo-second order model. The maximum monolayer adsorption capacity of nanocomposite for BPA was 46.2 mg/g at 20 °C. This study showed that the adsorption of BPA onto nanocomposite was spontaneous and thermodynamically desirable.