Magnetic ionic liquid aqueous two-phase system coupled with high performance liquid chromatography: A rapid approach for determination of chloramphenicol in water environment

Effervescence tablets based on magnetic ionic liquids as simple microdevices for the in situ dispersive liquid-liquid microextraction of urinary biomarkers

BACKGROUND

Magnetic ionic liquids (MILs) have been explored in dispersive liquid-liquid microextraction (DLLME). Their usage allows to substitute centrifugation and/or filtration steps by a quick magnetic separation. Besides, effervescence-assisted DLLME is one of the most known options to improve the dispersion of the extractant in the sample, while allowing to avoid the consumption of external energy during dispersion. Despite these interesting features, only one study incorporates MILs containing the tetrachloroferrate anion in effervescence tablets. These MILs are highly viscous and liquid at room temperature, thus compromising the stability of the tablets when used as extraction microdevices in effervescence-assisted DLLME, and only allowing their use in the conventional MIL-DLLME mode.

RESULTS

A new class of effervescence tablets containing a Ni(II)-based MIL, that is solid at room temperature, is here proposed. This type of tablets permits their use, for first time, in the in situ DLLME mode, occurring through the transformation of a water-soluble MIL into a water-insoluble MIL microdroplet. This way, the tablet formulation included: the MIL, the metathesis reagent lithium bis[(trifluoromethyl)sulfonyl]imide, NaH2PO4 and K2CO3 as effervescence precursors salts, and Na2SO4 as salting-out and desiccating agent. The method is combined with high-performance liquid-chromatography and both fluorescence and ultraviolet detection, for the determination of monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and benzophenones (BPs), as biomarkers in urine. The method simply involved the addition of the effervescence tablet to the sample, thus taken place simultaneously the effervescence process and the metathesis reaction, without requiring any external energy consumption. The method presented limits of detection down to 10 ng L-1 for OH-PAHs and to 0.60 μg L-1 for BPs, inter-day relative standard deviations lower than 17 %, and average relative recoveries of 94 % in urine. The determined OH-PAHs contents in urine were between 0.40 and 16 μg L-1, and between 17.8 and 334 μg L-1 for BPs.

SIGNIFICANCE

We have developed the first MIL-based effervescence tablets that are completely solid, thus improving the stability and robustness of these microdevices with respect to previously reported tablets involving MILs, while permitting to perform into the in situ DLLME mode (thus gaining in extraction efficiency). This approach including the MIL-based effervescence tablets constitutes an alternative on-site platform for the analysis of urine, as satisfactory precision, accuracy, and sensitivity are achieved despite not involving any external energy input within the analytical sample preparation setup. This method also constitutes the first application of MIL-based effervescence tablets for bioanalysis.

Magnetic Ionic Liquids: Current Achievements and Future Perspectives with a Focus on Computational Approaches

Magnetic ionic liquids (MILs) stand out as a remarkable subclass of ionic liquids (ILs), combining the desirable features of traditional ILs with the unique ability to respond to external magnetic fields. The incorporation of paramagnetic species into their structures endows them with additional attractive features, including thermochromic behavior and luminescence. These exceptional properties position MILs as highly promising materials for diverse applications, such as gas capture, DNA extractions, and sensing technologies. The present Review synthesizes key experimental findings, offering insights into the structural, thermal, magnetic, and optical properties across various MIL families. Special emphasis is placed on unraveling the influence of different paramagnetic species on MILs' behavior and functionality. Additionally, the Review highlights recent advancements in computational approaches applied to MIL research. By leveraging molecular dynamics (MD) simulations and density functional theory (DFT) calculations, these computational techniques have provided invaluable insights into the underlying mechanisms governing MILs' behavior, facilitating accurate property predictions. In conclusion, this Review provides a comprehensive overview of the current state of research on MILs, showcasing their special properties and potential applications while highlighting the indispensable role of computational methods in unraveling the complexities of these intriguing materials. The Review concludes with a forward-looking perspective on the future directions of research in the field of magnetic ionic liquids.

Current analytical strategies for the determination of quinolone residues in milk

Quinolones are potent antibacterial drugs extensively utilized for treating bacterial infections in poultry. However, the presence of quinolone antibiotic residues in milk is a matter of concern due to potential health risks and adverse effects on milk quality. This review provides an overview of current analytical strategies for the determination of quinolone residues in milk. Various sample preparation techniques, such as liquid-phase extraction, solid-phase extraction and QuEChERS, are discussed, along with detection methods including instrument-based detection, immune-based detection, and microbial detection. The advantages and limitations of each method are highlighted, as well as their applicability in different stages of milk production. Additionally, recent advancements in sample preparation and detection methods are presented. This comprehensive review aims to contribute to the development of accurate and reliable methods for the detection of quinolone residues in milk, ensuring the safety and quality of dairy products.

Lateral Flow Immunoassay Based on Quantum-Dot Nanobeads for Detection of Chloramphenicol in Aquatic Products

Quantum dot nanobeads (QBs) were used as signal source to develop competitive lateral flow immunoassay (LFIA) for the detection of chloramphenicol (CAP). The quantitative detection of CAP was achieved by calculating the total color difference (∆E) values of the test line (T line) using the images of test strips. QB-based LFIA (QBs-LFIA) allowed the effective dynamic linear detection of CAP in the range of 0.1-1.5 ng/mL. The limit of detection (LOD) was 3.0 ng/mL, which was 50 and 667 times lower than those achieved for two different brands of colloidal gold kits. The recoveries of CAP during real-sample detection were 82.82-104.91% at spiked levels of 0.1, 0.7, and 1.5 ng/mL. These results indicate that the developed QBs-LFIA facilitates the sensitive detection of CAP.

Novel Dual-Signal SiO2-COOH@MIPs Electrochemical Sensor for Highly Sensitive Detection of Chloramphenicol in Milk

In view of the great threat of chloramphenicol (CAP) to human health and the fact that a few producers have illegally used CAP in the food production process to seek economic benefits in disregard of laws and regulations and consumer health, we urgently need a detection method with convenient operation, rapid response, and high sensitivity capabilities to detect CAP in food to ensure people's health. Herein, a molecularly imprinted polymer (MIP) electrochemical sensor based on a dual-signal strategy was designed for the highly sensitive analysis of CAP in milk. The NiFe Prussian blue analog (NiFe-PBA) and SnS₂ nanoflowers were modified successively on the electrode surface to obtain dual signals from [Fe(CN)₆]^3-/4- at 0.2 V and NiFe-PBA at 0.5 V. SiO₂-COOH@MIPs that could specifically recognize CAP were synthesized via thermal polymerization using carboxylated silica microspheres (SiO₂-COOH) as carriers. When the CAP was adsorbed by SiO₂-COOH@MIPs, the above two oxidation peak currents decreased at the same time, allowing the double-signal analysis. The SiO₂-COOH@MIPs/SnS₂/NiFe-PBA/GCE sensor used for determining CAP was successfully prepared. The sensor utilized the interactions of various nanomaterials to achieve high-sensitivity dual-signal detection, which had certain innovative significance. At the same time, the MIPs were synthesized using a surface molecular imprinting technology, which could omit the time of polymerization and elution and met the requirements for rapid detection. After optimizing the experimental conditions, the detection range of the sensor was 10^-8 g/L-10^-2 g/L and the limit of detection reached 3.3 × 10^-9 g/L (S/N = 3). The sensor had satisfactory specificity, reproducibility, and stability, and was successfully applied to the detection of real milk samples.

Magnetic nanofluid based on green deep eutectic solvent for enrichment and determination of chloramphenicol in milk and chicken samples by high-performance liquid chromatography-ultraviolet: Optimization of microextraction

In this work, magnetic nanofluid based on a deep eutectic solvent that constricts through a simple and easy route, and subsequently applied for the preconcentration and microextraction of chloramphenicol (CAP) as a hazardous drug from milk and chicken samples via syringe-to-syringe microextraction prior to its determination by high-performance liquid chromatography-ultraviolet (HPLC-UV). In addition, the optimum conditions of effective factors were searched by the central composite design (CCD), and subsequently, at their optimum value, the figures of merit were evaluated. Also, the suggested method illustrated a low limit of detection (0.2 ng mL^-1), a low limit of quantitation (0.67 ng mL^-1), and a good linear range with an R² of 0.996. The CAP relative recoveries in milk and chicken samples were 90.3%-95.1%, with relative standard deviations lower than 4.2%. The current enhancement technique is simple, easy, and rapid, which makes it suitable for quantification of CAP by HPLC-UV at trace levels in complicated materials with reliable and reproducible results.

A Pyridine Diketopyrrolopyrrole-Grafted Graphene Oxide Nanocomposite for the Sensitive Detection of Chloramphenicol by a Direct Electrochemical Method

A novel direct electrochemical sensor, based on a pyridine diketopyrrolopyrrole/graphene oxide nanocomposite-modified glass carbon electrode (PDPP/GO/GCE), was developed herein for chloramphenicol (CAP) detection. In this research, PDPP was grafted onto GO by C-N bonds and π-π conjugation, which were synergistically confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The morphology study shows that PDPP was uniformly dispersed on the GO in the form of particles. The constructed PDPP/GO/GCE showed the strongest response signal to CAP in the evaluation of electrocatalytic activity by cyclic voltammetry compared to that of GO-modified and unmodified GCE, revealing that the introduction of PDPP can effectively improve the electrocatalytic activity of sensors. Moreover, PDPP/GO/GCE had a noticeable current signal when the concentration of CAP was as low as 0.001 uM and had a wide line range (0.01-780 uM) with a low limit of detection (1.64 nM). The sensor properties of the as-obtained PDPP/GO/GCE involved anti-interference, reproducibility, and stability, which were also evaluated and revealed satisfactory results.

A magnetic ionic liquid based vortex-assisted dispersive liquid-liquid microextraction coupled with back-extraction for the enrichment of fluoroquinolone antibiotics

In the present work, a magnetic ionic liquid (MIL) ([Co(DMBG)₂][Co(hfaca)₃]) was designed and synthesized with both the cation and anion respectively containing a paramagnetic component. With the prepared MIL as the extraction solvent, a vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) method was developed and combined with back-extraction for the enrichment of five fluoroquinolone antibiotics (FQs). The MIL can be easily collected and separated from the aqueous phase under an external magnetic field due to the strong magnetic susceptibility and red color. Some experimental factors affecting the extraction efficiency were investigated, and the optimum extraction efficiency was obtained in a basic solution (pH=9) for the extraction process and with 2% (v/v) formic acid as the back-extraction solvent. Under the optimized extraction and back-extraction conditions, the proposed method was validated and exhibited good linearity with coefficients of determination (R²) above 0.9956 in the range of 2.5-800 ng·mL^-1 and 5.0-800 ng·mL^-1, low limits of detection (LODs) within 0.75-1.5 ng·mL^-1 and satisfactory intra-day and inter-day precisions with relative standard deviations (RSDs) respectively less than 10.6% and 8.6%. Finally, the method was applied for the determination of five FQs in four samples of tap water, milk, honey and chicken, and good precision with RSDs of 0.5-9.5% and acceptable recoveries (73.8-114.3%) were obtained.

Magnetic Nanomaterials and Nanostructures in Sample Preparation Prior to Liquid Chromatography

Magnetic nanomaterials and nanostructures compose an innovative subject in sample preparation. Most of them are designed according to the properties of the target analytes on each occasion. The unique characteristics of nanomaterials enhance the proficiency at extracting and enriching due to their selective adsorption ability as well as easy separation and surface modification. Their remarkable properties, such as superparamagnetism, biocompatibility and selectivity have established magnetic materials as very reliable options in sample preparation approaches. In order to comprehend the range of utilization at magnetic materials and nanostructures, this review aims to present the most notable examples in sample preparation prior to liquid chromatography (LC) to the community of analytical chemists. Primarily, the review describes the principles of the techniques in which the magnetic materials are utilized and leaned on. Additionally, there is a diligent report about the novel magnetic techniques and finally a comparison to demonstrate the total point of view.

Chloramphenicol-activated electro-chemiluminescent behavior of BNQDs-Ru(phen)32+ system for ultra-sensitive sensing of chloramphenicol in pharmaceutical and milk samples

To improve the sensitivity for electro-chemiluminescent (ECL) detection of chloramphenicol (CAP), a common broad-spectrum antibiotic, boron nitride quantum dots (BNQDs) were prepared with excellent photoelectric property and low toxicity. After its structure and electrochemical property were investigated in detail, it was noted that the ECL signal of Ru(Phen)₃²⁺could be strengthened by the proposed BNQDs, which was further activated by ten's times in the presence of CAP. Under the optimized conditions, there was an excellent linear relationship between ΔECL and lgc_CAPin a wide linear range from 1.0 × 10^-10to 1.0 × 10^-6mol l^-1CAP. The detection limit was super-low to be 3.3 × 10^-11mol l^-1(S/N = 3). When applied for CAP detection in real pharmaceutical and food samples, the recoveries were between 97.8% and 105.7% with R.S.D. less than 3.3%. A possible CAP-activated ECL mechanism of BNQDs-Ru(phen)₃²⁺was also proposed. This work will offer a great potential for efficient monitoring of CAP pollution and clinical diagnosing of CAP-related diseases in future.

Miniaturized green sample preparation approaches for pharmaceutical analysis

The development of green sample preparation procedures is an extremely important research field in which more and more applications are constantly being proposed in different areas, including pharmaceutical analysis. This review article is aimed at providing a general overview of the development of miniaturized green analytical sample preparation procedures in the pharmaceutical analysis field, with special focus on the works published between January 2017 and July 2021. Particular attention has been paid to the application of environmentally friendly solvents and sorbents as well as nanomaterials or high extraction capacity sorbents in which the solvent volumes and reagents amounts are drastically reduced, with their subsequent advantages from the sustainability point of view.

A review of green solvent extraction techniques and their use in antibiotic residue analysis

Antibiotic residues are being continuously recognized in the aquatic environment and in food. Though the concentration of antibiotic residues is typically low, adverse effects on the environment and human health have been observed. Hence, an efficient method to determine numerous antibiotic residues should be simple, inexpensive, selective, with high throughput and with low detection limits. Liquid-based extractions have been exceedingly used for clean-up and preconcentration of antibiotics prior to chromatographic analysis. In order to make methods more green and environmentally sustainable, conventional hazardous organic solvents can be replaced with green solvents. This review presents sampling strategies as well as comprehensive and up-to-date methods for chemical analysis of antibiotic residues in different sample matrices. Particularly, solvent-based sample preparation techniques using green solvents are discussed along with applications in antibiotic residue analysis.

Advances Brought by Hydrophilic Ionic Liquids in Fields Involving Pharmaceuticals

The negligible volatility and high tunable nature of ionic liquids (ILs) have been the main drivers of their investigation in a wide diversity of fields, among which is their application in areas involving pharmaceuticals. Although most literature dealing with ILs is still majorly devoted to hydrophobic ILs, evidence on the potential of hydrophilic ILs have been increasingly provided in the past decade, viz., ILs with improved therapeutic efficiency and bioavailability, ILs with the ability to increase drugs' aqueous solubility, ILs with enhanced extraction performance for pharmaceuticals when employed in biphasic systems and other techniques, and ILs displaying low eco/cyto/toxicity and beneficial biological activities. Given their relevance, it is here overviewed the applications of hydrophilic ILs in fields involving pharmaceuticals, particularly focusing on achievements and advances witnessed during the last decade. The application of hydrophilic ILs within fields involving pharmaceuticals is here critically discussed according to four categories: (i) to improve pharmaceuticals solubility, envisioning improved bioavailability; (ii) as IL-based drug delivery systems; (iii) as pretreatment techniques to improve analytical methods performance dealing with pharmaceuticals, and (iv) in the recovery and purification of pharmaceuticals using IL-based systems. Key factors in the selection of appropriate ILs are identified. Insights and perspectives to bring renewed and effective solutions involving ILs able to compete with current commercial technologies are finally provided.

Magnetic Ionic Liquids in Sample Preparation: Recent Advances and Future Trends

In the last decades, a myriad of materials has been synthesized and utilized for the development of sample preparation procedures. The use of their magnetic analogues has gained significant attention and many procedures have been developed using magnetic materials. In this context, the benefits of a new class of magnetic ionic liquids (MILs), as non-conventional solvents, have been reaped in sample preparation procedures. MILs combine the advantageous properties of ionic liquids along with the magnetic properties, creating an unsurpassed combination. Owing to their unique nature and inherent benefits, the number of published reports on sample preparation with MILs is increasing. This fact, along with the many different types of extraction procedures that are developed, suggests that this is a promising field of research. Advances in the field are achieved both by developing new MILs with better properties (showing either stronger response to external magnetic fields or tunable extractive properties) and by developing and/or combining methods, resulting in advanced ones. In this advancing field of research, a good understanding of the existing literature is needed. This review aims to provide a literature update on the current trends of MILs in different modes of sample preparation, along with the current limitations and the prospects of the field. The use of MILs in dispersive liquid–liquid microextraction, single drop microextraction, matrix solid-phase dispersion, etc., is discussed herein among others.

Application of aqueous two-phase system for selective extraction and clean-up of emerging contaminants from aqueous matrices

This review approaches how aqueous two-phase systems (ATPS), in their various compositions (e.g., polymer + salt, copolymer + salt, ionic liquid + salt, acetonitrile + salt), can be efficiently used for extraction, preconcentration, and clean-up of analytes in aqueous samples to determine the compounds classified as emerging contaminants (ECs). In the literature, there are some studies using ATPS applied to ECs, like pesticides, pharmaceuticals, illicit drugs, personal care products, alkaloids, and hormones, even when in trace concentrations. The ATPS is an alternative to the conventional liquid-liquid extraction technique. However, it is predominantly composed of water and do not generally use organic solvents and, therefore, is based on the principles of green chemistry. An ATPS approach has a unique advantage because it can extract neutral, anionic, cationic, polar, and nonpolar compounds, even when present simultaneously in the same sample. This review covers how this simple and low environmental impact technique has been employed for the analysis of different classes of emerging contaminants.

A facile synthesis of two ionized fluorescent carbon dots and selective detection toward Fe2+ and Cu2

In this study, a facile synthesis of two ionized carbon dots (CDs-2 and CDs-3) is reported, in which different ionic pairs are formed at the surface of the carbon core. In contrast to CDs-3, the accumulation of carbon core can be clearly observed in the TEM image of CDs-2. This is due to the linkage of the dibromine alkyl group. Compared with naked CDs in the absence of the ionic pair, the maximum emission wavelength undergoes a red-shift of nearly 60 nm. Moreover, protic solvents (water, ethanol and N,N'-dimethyl formamide) have an apparent effect on the emission intensities of CDs-2 and CDs-3. The time-resolved average lifetimes of CDs-2 and CDs-3 are calculated as 56.34 ns and 54.50 ns, respectively. Furthermore, they both have much better fluorescence stability in the solution with pH ranging from 2 to 11 due to the presence of the imidazolium cation. It is interesting to see that CDs-2 and CDs-3 have much different responses towards Cu²⁺ and Fe²⁺. The CDs-3 solution generates clear fluorescence quenching when treated with Fe²⁺. In brief, we believe that these findings can inspire more research developments in the synthesis and further application of functional CDs.

Covalently bonded aptamer-functionalised magnetic mesoporous carbon for high-efficiency chloramphenicol detection

A novel aptamer-modified magnetic mesoporous carbon was prepared to develop a specific and sensitive magnetic solid-phase extraction method through combination with ultra-high performance liquid chromatography-tandem mass spectrometry for the analysis chloramphenicol in complex samples. More specifically, the chloramphenicol aptamer-modified Mg/Al layered double hydroxide magnetic mesoporous carbon was employed as a novel magnetic solid-phase extraction sorbent for analyte enrichment and sample clean-up. The extraction solvent, extraction time, desorption solvent, and desorption time were investigated. It was found that the mesoporous structure and aptamer-based affinity interactions resulted in acceptable selective recognition and a good chemical stability toward trace amounts of chloramphenicol. Upon combination with the ultra-high performance liquid chromatography-tandem mass spectrometry technique, a specific and sensitive recognition method was developed with a low limit of detection (0.94 pmol/L, S/N = 3) for chloramphenicol analysis. The developed method was successfully employed for the determination of chloramphenicol in complex serum, milk powders, fish and chicken samples, giving recoveries of 87.0-107% with relative standard deviations of 3.1-9.7%.

The C-H activated controlled mono- and di-olefination of arenes in ionic liquids at room temperature

In this study, controlled mono and di-olefination of arenes was first realized at room temperature via the C-H bond activation in ionic liquids, probably due to the positive effects of ionic liquids. It is an energy-saving routes in industrial production without the need for heating equipment. Different catalysts were screened, and it was found that [Ru(p-cymene)Cl2]2 generated mono-olefinated products predominantly while [Cp*RhCl2]2 selectively gave di-olefinated products. These catalysts ([BMIM]NTf2 and [BMIM]PF6) as green and recyclable reaction media are highly efficient under mild conditions. This reaction process can avoid any volatile and environmentally toxic organic solvents, and is much safer without the need for pressure-tight equipment. A wide substrate scope with good yields and satisfactory selectivity was achieved. The reactions can be scaled up to gram-scale. Furthermore, an expensive rhodium/ruthenium catalytic system was recycled for at least 6 times with consistently high catalytic activity, which was economical and environmental friendly from an industrial point of view. According to the mechanistic study, the C-H bond cleavage was probably achieved via the concerted metalation-deprotonation. This technique can be applied in the synthesis of various valuable unsaturated aromatic compounds and shows a great potential for industrial production.

The Influence of Ionic Liquids on the Effectiveness of Analytical Methods Used in the Monitoring of Human and Veterinary Pharmaceuticals in Biological and Environmental Samples-Trends and Perspectives

Recent years have seen the increased utilization of ionic liquids (ILs) in the development and optimization of analytical methods. Their unique and eco-friendly properties and the ability to modify their structure allows them to be useful both at the sample preparation stage and at the separation stage of the analytes. The use of ILs for the analysis of pharmaceuticals seems particularly interesting because of their systematic delivery to the environment. Nowadays, they are commonly detected in many countries at very low concentration levels. However, due to their specific physiological activity, pharmaceuticals are responsible for bioaccumulation and toxic effects in aquatic and terrestrial ecosystems as well as possibly upsetting the body's equilibrium, leading to the dangerous phenomenon of drug resistance. This review will provide a comprehensive summary of the use of ILs in various sample preparation procedures and separation methods for the determination of pharmaceuticals in environmental and biological matrices based on liquid-based chromatography (LC, SFC, TLC), gas chromatography (GC) and electromigration techniques (e.g., capillary electrophoresis (CE)). Moreover, the advantages and disadvantages of ILs, which can appear during extraction and separation, will be presented and attention will be given to the criteria to be followed during the selection of ILs for specific applications.

From Paramagnetic to Superparamagnetic Ionic Liquid/Poly(ionic liquid): The Effect of π-π Stacking Interaction

Magnetic ionic liquids (MILs) and poly(magnetic ionic liquids) (PMILs) with FeCl₄^- as anions usually show weak magnetism, such as paramagnetism or antiferromagnetism, at room temperature. Inspired by the natural inorganic ferromagnet with ordered crystal structures, a soft superparamagnetic ionic liquid (TMBBDI[FeCl₄]) and corresponding poly(ionic liquid) (PTMBBDI[FeCl₄]) were prepared by introducing π-π stacking biphenyl groups into the organic cations. Both of the compounds exhibited superparamagnetism from 100 to 300 K, while a ferromagnetic hysteresis loop was found at 300 K. Ferromagnetic interactions were observed from zero field cooling and field cooling studies for both TMBBDI[FeCl₄] and PTMBBDI[FeCl₄]. However, the MIL and PMIL without π-π stacking interaction were paramagnetic without ferromagnetic interaction. The superparamagnetism of the TMBBDI[FeCl₄] and PTMBBDI[FeCl₄] was ascribed to the π-π stacking interactions between biphenyl groups, which not only shortened the Fe-Fe distance to the ferromagnetic interaction range but also increased the order degree of the molecules.

Impedimetric ultrasensitive detection of chloramphenicol based on aptamer MIP using a glassy carbon electrode modified by 3-ampy-RGO and silver nanoparticle

In this research work, a biosensor with a dual recognition system was fabricated and founded on a combination of aptasensing and the molecular imprinting union of the chloramphenicol (CAP) selective detection. CAP, is an antibiotic, was applied in veterinary and human in order to treat gram-positive and gram-negative infections. It is worth mentioning that CAP residue brings about earnest side effects on human health. According to this, in this sensing system, 3-aminomethyl pyridine functionalized graphene oxide (GO) (3-ampy-RGO) has been coated on the surface of GCE. Afterwards, the silver nanoparticle (AgNPs) was coated on the 3-ampy-RGO/GCE and, then, the CAP complex-amino-aptamer (NH₂-Apt[CAP]) was attached to the AgNP/3-ampy-RGO/GCE using a kind of bonding formation of Ag-N. In this sense, it is worth noting that the resorcinol electropolymerization around the complex of aptamer/CAP would confine the complex and, then, retain the aptamer. Following the CAP removal, the MIP cavity, as it was supposed, synergistically acted with that of the embedded aptamer in order to construct a nanohybrid receptor. Interestingly, the double exact property of the molecular imprinting polymers and aptamers led to the superb sensing properties. In the mentioned system it was illustrated that the linear range was from 1.0 pM to 1.0 nM with the detection limit of 0.3 pM; consequently, as observed, it was better than or as good as other similar assays. Moreover, the mentioned system whose activity was observed in the various interferences presence showed great selectivity in detected the CAP. Finally, the designed sensor exhibited outstanding results when applied to detect CAP in milk samples.

Ionic Liquid Aqueous Two-Phase Systems From a Pharmaceutical Perspective

Aqueous Two-Phase Systems (ATPSs) have been extensively studied for their ability to simultaneously separate and purify active pharmaceutical ingredients (APIs) and key intermediates with high yields and high purity. Depending on the ATPS composition, it can be adapted for the separation and purification of cells, nucleic acids, proteins, antibodies, and small molecules. This method has been shown to be scalable, allowing it to be used in the milliliter scale for early drug development to thousands of liters in manufacture for commercial supply. The benefits of ATPS in pharmaceutical separations is increasingly being recognized and investigated by larger pharmaceutical companies. ATPSs use identical instrumentation and similar methodology, therefore a change from traditional methods has a theoretical low barrier of adoption. The cost of typical components used to form an ATPS at large scale, particularly that of polymer-polymer systems, is the primary challenge to widespread use across industry. However, there are a few polymer-salt examples where the increase in yield at commercial scale justifies the cost of using ATPSs for macromolecule purification. More recently, Ionic Liquids (ILs) have been used for ATPS separations that is more sustainable as a solvent, and more economical than polymers often used in ATPSs for small molecule applications. Such IL-ATPSs still retain much of the attractive characteristics such as customizable chemical and physical properties, stability, safety, and most importantly, can provide higher yield separations of organic compounds, and efficient solvent recycling to lower financial and environmental costs of large scale manufacturing.

Enhanced magnetic ionic liquid-based dispersive liquid-liquid microextraction of triazines and sulfonamides through a one-pot, pH-modulated approach

In this study, an enhanced variant of magnetic ionic liquid (MIL)-based dispersive liquid-liquid microextraction is put forward. The procedure combines a water insoluble solid support and the [P₆₆₆₁₄⁺][Dy(III)(hfacac)₄^-] MIL, in a one-pot, pH-modulated procedure for microextraction of triazines (TZs) and sulfonamides (SAs). The solid supporting material was mixed with the MIL to overcome difficulties concerning the weighing of MIL and to control the uniform dispersion of the MIL, rendering the whole extraction procedure more reproducible. The pH-modulation during extraction step makes possible the one-pot extraction of SAs and TZs, from a single sample, in 15 min. Overall, the new analytical method developed enjoys the benefits of sensitivity (limits of quantification: 0.034-0.091 μg L^-1) and precision (relative standard deviation: 5.2-8.1%), while good recoveries (i.e., 89-101%) were achieved from lake water and effluent from a municipal wastewater treatment plant. Owing to all of the above, the new procedure can be used to determine the concentrations of SAs and TZs at levels below the maximum residue limits.

Aqueous Two-Phase Systems at Large Scale: Challenges and Opportunities

Aqueous two-phase systems (ATPS) have proved to be an efficient and integrative operation to enhance recovery of industrially relevant bioproducts. After ATPS discovery, a variety of works have been published regarding their scaling from 10 to 1000 L. Although ATPS have achieved high recovery and purity yields, there is still a gap between their bench-scale use and potential industrial applications. In this context, this review paper critically analyzes ATPS scale-up strategies to enhance the potential industrial adoption. In particular, large-scale operation considerations, different phase separation procedures, the available optimization techniques (univariate, response surface methodology, and genetic algorithms) to maximize recovery and purity and economic modeling to predict large-scale costs, are discussed. ATPS intensification to increase the amount of sample to process at each system, developing recycling strategies and creating highly efficient predictive models, are still areas of great significance that can be further exploited with the use of high-throughput techniques. Moreover, the development of novel ATPS can maximize their specificity increasing the possibilities for the future industry adoption of ATPS. This review work attempts to present the areas of opportunity to increase ATPS attractiveness at industrial levels.

Ultrasonic Assisted Extraction of Paclitaxel from Taxus x media Using Ionic Liquids as Adjuvants: Optimization of the Process by Response Surface Methodology

(1) Background: Ionic liquids (ILs) are considered "green" solvents and have been widely used in the extraction and separation field in recent years; (2) Methods: In this study, some common ILs and functionalized magnetic ionic liquids (MILs) were used as adjuvants for the solvent extraction of paclitaxel from Taxus x media (T. x media) using methanol solution. The extraction conditions of methanol concentration, IL type and amount, solid-liquid ratio, extraction temperature, and ultrasonic irradiation time were investigated in single factor experiments. Then, three factors of IL amount, solid-liquid ratio, and ultrasonic irradiation time were optimized by response surface methodology (RSM); (3) Results: The MIL [C₄MIM]FeCl₃Br was screened as the optimal adjuvant. Under the optimization conditions of 1.2% IL amount, 1:10.5 solid-liquid ratio, and 30 min ultrasonic irradiation time, the extraction yield reached 0.224 mg/g; and (4) Conclusions: Compared with the conventional solvent extraction, this ultrasonic assisted extraction (UAE) using methanol and MIL as adjuvants can significantly improve the extraction yield, reduce the use of methanol, and shorten the extraction time, which has the potentiality of being used in the extraction of some other important bioactive compounds from natural plant resources.

Green aqueous biphasic systems containing deep eutectic solvents and sodium salts for the extraction of protein

Deep eutectic solvents (DESs), a new type of green solvents, were applied for the extraction of proteins with aqueous biphasic systems (ABSs) in this study.