An Eco-Friendly Hydrophobic Deep Eutectic Solvent-Based Dispersive Liquid-Liquid Microextraction for the Determination of Neonicotinoid Insecticide Residues in Water, Soil and Egg Yolk Samples

Deep Eutectic Solvents for Extraction and Preconcentration of Organic and Inorganic Species in Water and Food Samples: A Review

Deep eutectic solvents (DESs) have been developed as green solvents and these are capable as alternatives to conventional solvents used for the extraction of organic and inorganic species from food and water samples. The continuous generation of contaminated waste and increasing concern for the human health and environment have compelled the scientific community to investigate more ecological schemes. In this concern, the use of DESs have developed in one of the chief approach in the field of chemistry. These solvents have appeared as a capable substitute to conventional hazardous solvents and ionic liquids. The DESs has distinctive properties, easy preparation and components availability. It is not only used in scienctific fields but also used in quotidian life. There are many advantages of DESs in analytical chemistry, they are largely used for extraction and determination of inorganic and organic compounds from different samples. In previous a few years, several advanced researches have been focused on the separation and preconcentration of low level of pollutants using DESs as the extractants. This review summarizes the use of DESs in the separation and preconcentration of organic and inorganic species from water and food samples using various microextraction processes.

Development and Validation of a High-Performance Liquid Chromatography Diode Array Detector Method to Measure Seven Neonicotinoids in Wheat

Neonicotinoids (NEOs), used as insecticides against aphids, whiteflies, lepidopterans, and beetles, have numerous detrimental impacts on human health, including chronic illnesses, cancer, infertility, and birth anomalies. Monitoring the residues in food products is necessary to guarantee public health and ecological balance. The present work validated a new method to measure seven neonicotinoid insecticides (acetamiprid ACT, clothianidin CLT, dinotefuran DNT, imidacloprid IMD, nitenpyram NTP, thiacloprid TCP, and thiamethoxan THT) in wheat. The analytical procedure was based on simple and fast wheat sample cleanup using solid-phase extraction (SPE) to remove interferents and enrich the NEOs, alongside the NEOs' separation and quantification by reverse-phase chromatography coupled with a diode array detector (DAD). The validation process was validated using the accuracy profile strategy, a straightforward decision tool based on the measure of the total error (bias plus standard deviation) of the method. Our results proved that, in the future, at least 95% of the results obtained with the proposed method would fall within the ±15% acceptance limits. The test's cost-effectiveness, rapidity, and simplicity suggest its use for determining the levels of acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam in routine analyses of wheat.

Reviewing neonicotinoid detection with electroanalytical methods

Neonicotinoids, as the fastest-growing class of insecticides, currently account for over 25% of the global pesticide market. Their effectiveness in controlling a wide range of pests that pose a threat to croplands, home yards/gardens, and golf course greens cannot be denied. However, the extensive use of neonicotinoids has resulted in significant declines in nontarget organisms such as pollinators, insects, and birds. Furthermore, the potential chronic, sublethal effects of these compounds on human health remain largely unknown. To address these pressing issues, it is crucial to explore and understand the capabilities of electrochemical sensors in detecting neonicotinoid residues. Surprisingly, despite the increasing importance of this topic, no comprehensive review article currently exists in the literature. Therefore, our proposed review aims to bridge this gap by providing a thorough analysis of the use of electrochemical methods for neonicotinoid determination. In this review article, we will delve into various aspects of electrochemical analysis, including the influence of electrode materials, employed techniques, and the different types of electrode mechanisms utilized. By synthesizing and analysing the existing research in this field, our review will offer valuable insights and guidance to researchers, scientists, and policymakers alike.

Preconcentration of Heterocyclic Aromatic Amines in Edible Fried Insects Using Surfactant-Assisted Hydrophobic Deep Eutectic Solvent for Homogeneous Liquid-Liquid Microextraction prior to HPLC

Thermal processing techniques are often accompanied by the production of many harmful compounds such as heterocyclic aromatic amines (HAAs). To protect human health, an efficient and environmentally friendly method, namely, homogeneous liquid-liquid microextraction (HLLME), was investigated. This method is based on a surfactant-assisted hydrophobic deep eutectic solvent for the determination of HAAs in edible fried insect samples prior to their analysis by high-performance liquid chromatography coupled with UV detection. A hydrophobic deep eutectic solvent (as extraction solvent) was synthesized using decanoic acid as a hydrogen bond donor and tetrabutylammonium bromide (TBABr) as a hydrogen bond acceptor and then characterized by Fourier transform infrared (FTIR) spectroscopy. The surfactant was used as the emulsifier and induces mass transfer, resulting in an increasing extraction efficiency of the proposed method. Various factors affecting the extraction performance were investigated and optimized. A matrix-match calibration method was used to analyze HAAs in high heat-treated edible fried insect samples. Under optimized conditions, the proposed method showed good linearity (R2 ≥ 0.99) with satisfactory limits of detection and satisfactory reproducibility with relative standard deviation of less than 10.0%. Furthermore, the procedure greenness was assessed using the Analytical Eco-Scale. This paper represents the first application of HLLME based on a surfactant-assisted hydrophobic deep eutectic solvent to analyze HAAs in edible fried insect samples.

A review on natural based deep eutectic solvents (NADESs): fundamentals and potential applications in removing heavy metals from soil

Natural based deep eutectic solvent (NADES) is a promising green solvent to replace the conventional soil washing solvent due to the environmental benign properties such as low toxicity, high biodegradability, high polarity or hydrophilicity, and low cost of fabrication process. The application of NADES is intensively studied in the extraction of organic compounds or natural products from vegetations or organic matters. Conversely, the use of the solvent in removing heavy metals from soil is severely lacking. This review focuses on the potential application of NADES as a soil washing agent to remove heavy metal contaminants. Hydrophilicity is an important feature of a NADES to be used as a soil washing solvent. In this context, choline chloride is often used as hydrogen bond acceptor (HBA) whereby choline chloride based NADESs showed excellent performance in the extraction of various solutes in the past studies. The nature of NADES along with its chemistry, preparation and designing methods as well as potential applications were comprehensively reviewed. Subsequently, related studies on choline chloride-based NADES in heavy metal polluted soil remediation were also reviewed. Potential applications in removing other soil contaminants as well as the limitations of NADES were discussed based on the current advancements of soil washing and future research directions were also proposed.

Synthesis of phosphate-functionalized magnetic porous organic polymer: A sorbent for sensitive determination of neonicotinoid insecticides in water and lemon juice

There is an urgent need to prepare advanced functional materials for extraction and enrichment of trace organic pollutants from different samples. In this work, two novel phosphate-functionalized porous organic polymers (DBP-POP and DPP-POP) were synthesized for the first time. Compared with phosphate-free counterpart, both phosphate-functionalized POPs showed excellent adsorption performance for the neonicotinoids due to the hydrogen bonding, π-π interaction and hydrophobic interaction. For ease of separating the sorbent from solution, magnetic DBP-POP (M-DBP-POP) was further prepared as sorbent to extract neonicotinoids from environmental water and lemon juice samples prior to their determination by high performance liquid chromatography-ultraviolet detection. Under optimal conditions, the detection limits (S/N = 3) of the method were 0.01-0.08 ng mL-1 for water and 0.03-0.10 ng mL-1 for lemon juice. The recoveries were in the range of 80.0% to 113.0% with relative standard deviation less than 10.6%. This work demonstrated the feasibility of phosphate-functionalized POPs for adsorption applications.

Trace-Level Determination of Triazole Fungicides Using Effervescence-Assisted Liquid-Liquid Microextraction Based on Ternary Deep Eutectic Solvent Prior to High-Performance Liquid Chromatography

A simple and sensitive preconcentration method, namely, effervescence-assisted liquid-liquid microextraction based on the ternary deep eutectic solvent method, was developed for enrichment of triazole fungicide residues prior to their determination by high-performance liquid chromatography coupled with UV detection. In this method, a ternary deep eutectic solvent (as extractant) was prepared by combination of octanoic acid, decanoic acid, and dodecanoic acid. The solution was well dispersed with sodium bicarbonate (as effervescence powder) without using auxiliary devices. In order to obtain relatively high extraction efficiency, analytical parameters were investigated and optimized. Under optimum conditions, the proposed method showed good linearity within the range of 1-1000 μg L^-1 with a coefficient for determination (R²) greater than 0.997. The low limits of detection (LODs) were in the range of 0.3-1.0 μg L^-1. The precisions were assessed from the relative standard deviations (RSDs) of retention time and peak area obtained from intra- (n = 3) and inter-day (n = 5 × 5) experiments, which were greater than 1.21 and 4.79%, respectively. Moreover, the proposed method provided high enrichment factors ranging from 112 to 142 folds. A matrix-match calibration method was used for analysis of real samples. Finally, the developed method was successfully applied for determination of the triazole fungicide in environmental water (near agricultural area), honey, and bean samples, and it represents a promising alternative method for analysis of triazoles. The recoveries of the studied triazoles were obtained in the range of 82-106% with an RSD less than 4.89.

Simultaneous determination of ten neonicotinoid insecticides and a metabolite in human whole blood by QuEChERS coupled with UPLC-Q Exactive orbitrap high-resolution mass spectrometry

Since neonicotinoid insecticides are now the most extensively used insecticides worldwide, there are increasing cases of neonicotinoid poisoning. A rapid and sensitive method was developed for the determination of ten neonicotinoid insecticides and a metabolite 6-chloronicotinic acid in human whole blood. The types and amounts of extraction solvent, salting-out agent, and adsorbent in the QuEChERS method were optimized by comparing the absolute recoveries of 11 analytes. The separation was performed on an Agilent EC18 column with the gradient elution with 0.1% formic acid in water and acetonitrile as the mobile phase. The quantification was achieved by Q Exactive orbitrap high-resolution mass spectrometry under parallel reaction monitoring scan mode. The 11 analytes showed good linearity with R² ≥ 0.9950, LODs ranging from 0.01 μg/L to 0.30 μg/L, and LOQs from 0.05 μg/L to 1.00 μg/L. The recoveries ranged from 78.3% to 119.9% at low, medium, and high spiked concentrations of blank blood, with matrix effects ranging from 80.9% to 117.8%, inter-day RSDs from 0.7% to 6.7%, and intra-day RSDs from 2.7% to 9.8%. The method was furthermore applied to a real case of neonicotinoid insecticide poisoning to demonstrate its feasibility. The proposed method is suitable for the rapid screening of neonicotinoid insecticides in poisoned human blood in the field of forensic science, as well as monitoring of neonicotinoid insecticide residues in humans in the field of environmental safety, compensating for a lack of studies on neonicotinoid insecticide determination in biological samples.

Thymol-Based Hydrophobic Deep Eutectic Solvents as a Green Approach for Screening Polar Nitrosamines in Sartans Pharmaceutical Products by Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Combined with HPLC-DAD

Nitrosamines are carcinogens substances firstly detected in sartans drugs in 2018, leading to new regulations and monitoring programmes that raised the costs and challenges to the pharmaceutical industry. Therefore, reliable and cost-effective methods for screening nitrosamines in medicines are highly desirable. Hydrophobic deep eutectic solvents (HDES), a novel "eco-friendly" alternative to solvents commonly used in microextraction techniques, can meet these requirements. In this study, a simple and rapid method of ultrasound-assisted dispersive liquid-liquid microextraction using thymol-based HDES followed by HPLC-DAD detection was developed for the determination of n-nitrosodimethylamine (NDMA) and n-nitroso-n-methylamino butyric acid (NMBA) from candesartan, irbesartan, losartan, olmesartan, telmisartan and valsartan drug substances, and from losartan tablets. Various influencing factors (such as HDES type, HDES:sample ratio, salt addition and sample pH) were investigated. Best extraction efficiencies were achieved with thymol:benzyl alcohol HDES. Under optimal conditions, the linearities ranged from 15 to 1000 ng mL^-1 for both NDMA and NMBA (R² > 0.99), with recoveries between 81.8-104.2% and precision from 0.2 to 14.6%. The limits of detection were 17.3 - 220.0 ng g^-1 and 16.3 - 290.0 ng g^-1 for NDMA and NMBA, consecutively. Finally, the proposed method was successfully applied in spiked sartans drug substances and in losartan potassium tablets collected in the market.

Hydrophobic deep eutectic solvent-based ultrasonic-assisted liquid-liquid microextraction combined with GC for eugenol, isoeugenol, and methyl isoeugenol determination in aquatic products

The use of deep eutectic solvents (DESs) has great prospects because of the green and efficient characteristics, which can be used for developing analytical methods for foods. In this research, assisted by ultrasonic waves, a liquid-liquid microextraction detection method combined with gas chromatography was established for three anaesthetics (eugenol, isoeugenol, and methyl isoeugenol) in aquatic food. The processing conditions including the components, ratio of hydrogen bond acceptor and hydrogen bond donor, DES volume, ultrasonic time, and pH were evaluated and optimised to improve the extraction efficiency, which was based on the DES structures and properties. In-house method validation was carried out by applying to real samples. A Thymol: levulinic acid DES (with a molar ratio of 1:2) was used as the extractant and the recoveries were as high as 93-101% for eugenol, 90-100% for methyl isoeugenol, and 86-94% for isoeugenol with RSDs <5% under optimum conditions. The limit of detection and quantification of the eugenol compounds were 0.08-0.10 μg/mL and 0.26-0.33 μg/mL, respectively. The method has green credentials and comparable LOD to homologous apparatus, which can be used for the determination of eugenol components in aquatic food.

Effectiveness of a novel polyaniline@Fe-ZSM-5 hybrid composite for Orange G dye removal from aqueous media: Experimental study and advanced statistical physics insights

A polyaniline@Fe-ZSM-5 composite was synthesized via an in situ interfacial polymerization procedure. The morphology, crystallinity, and structural features of the as-developed PANI@Fe-ZSM-5 composite were assessed using scanning electron microscopy - energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The composite was efficiently employed for the first time as an adsorbent Orange G (OG) dyestuff from water. The OG dye adsorption performance was investigated as a function of several operating conditions. The kinetic study demonstrated that a pseudo-second-order model was appropriate to anticipate the OG adsorption process. The maximum adsorption capacity was found to be 217 mg/g. The adsorption equilibrium data at different temperatures were calculated via advanced statistical physics formalism. The entropy function indicated that the disorder of OG molecules improved at low concentrations and lessened at high concentrations. The free enthalpy and internal energy functions suggested that the OG adsorption was a spontaneous process and physisorption in nature. Regeneration investigation showed that the PANI@Fe-ZSM-5 could be effectively reused up to five cycles. The main results of this work provided a deep insight on the experimental study supported by advanced statistical physics prediction for the adsorption of Orange G dye onto the novel polyaniline@Fe-ZSM-5 hybrid composite. Additionally, the experimental and advanced statistical physics findings stated in this study may arouse research interest in the field of wastewater treatment.

Neoteric deep eutectic solvents: history, recent developments, and catalytic applications

Deep eutectic solvents (DESs) are modified versions of ionic liquids (ILs) and are formed by the fusion of polar components (liquids or solids) via hydrogen bonding interactions. DESs are prepared by the simple mixing of two or three cheap constituents (that are capable of self-association) with gentle heating, which leads to a drastic decrease in their melting points. The resultant clear homogeneous mixture consists of cations, anions, as well as neutral molecules; this will contribute both ionic and molecular solvent properties to the DESs. DESs have emerged as alternatives to conventional organic solvents and ILs, which meet different criteria such as availability, low cost, low toxicity, biodegradability, recyclability, ease of preparation method, tunable, and designer physiochemical properties. Many of them have attracted considerable attention and haave been applied in distinct fields of chemistry. To summarize the full-scale development of DESs, this review discusses the history, classifications, various methods of preparation, properties, and some major applications in catalysis in the last three years. This review is expected to be helpful for the further development of DESs based on a summary of the fundamental research in the field.

Application of Extraction and Determination Based on Deep Eutectic Solvents in Different Types of Environmental Samples

Water sources are an indispensable resource for human survival. Monitoring the pollution status of the surrounding environment is necessary to protect water sources. Research on the environmental matrix of deep eutectic solvents (DESs) has expanded rapidly because of their high extraction efficiency for various target analytes, controllable synthesis, and versatile structure. Following the synthesis of hydrophobic deep eutectic solvents (HDESs), their application in aqueous matrices broadened greatly. The present review conducted a survey on the pollutant extraction methods based DESs in environmental matrices from two aspects, application methods and matrix types; discussed the potential risk of DESs to the environment and future development trends; and provided some references for researchers to choose DES-based extraction methods for environmental research.

Deep Eutectic Solvents Application in Food Analysis

Current trends in Analytical Chemistry are focused on the development of more sustainable and environmentally friendly procedures. However, and despite technological advances at the instrumental level having played a very important role in the greenness of the new methods, there is still work to be done regarding the sample preparation stage. In this sense, the implementation of new materials and solvents has been a great step towards the development of "greener" analytical methodologies. In particular, the application of deep eutectic solvents (DESs) has aroused great interest in recent years in this regard, as a consequence of their excellent physicochemical properties, general low toxicity, and high biodegradability if they are compared with classical organic solvents. Furthermore, the inclusion of DESs based on natural products (natural DESs, NADESs) has led to a notable increase in the popularity of this new generation of solvents in extraction techniques. This review article focuses on providing an overview of the applications and limitations of DESs in solvent-based extraction techniques for food analysis, paying especial attention to their hydrophobic or hydrophilic nature, which is one of the main factors affecting the extraction procedure, becoming even more important when such complex matrices are studied.

[Progress in the application of deep eutectic solvents to extraction and separation technology]

With the rapid development of green chemistry, the design and application of the related methods and requisite solvents have received increasing attention in recent years. Deep eutectic solvents (DESs) are mixtures formed from a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD). Generally, ionic liquids (ILs) and DESs have similar physical and chemical properties, and hence, find application in the same fields. However, DESs have many advantages over ILs, such as non-toxicity, environmental friendliness, low cost, and biodegradability. Thus, there are many areas where DESs play a key role and act as new, efficient green extraction solvents. DESs can aid the extraction and separation of different target compounds from a variety of samples, thus promoting the rapid development of sample pretreatment technology. As extraction solvents, DESs offer unique advantages. In dispersive liquid-liquid microextraction (DLLME), DESs show incredible ability to extract residual drugs, metal ions, and bioactive components from complex matrices, which would require complicated sample preparation steps when using traditional organic extraction solvents. Compared with traditional organic extraction solvents, DESs have considerable merits of greenness, hypotoxicity, higher extraction efficiency, etc. Moreover, as a dispersant, a DES can accelerate the diffusion of the extractant in the sample solution during DLLME, owing to its benefits of miniaturization and low cost. Traditional dispersants such as methanol and acetonitrile have many disadvantages, including high volatility, flammability, and toxicity, while DESs are environmentally friendly. Therefore, the combination of DES and DLLME has recently gained prominence in the field of sample preparation. Additionally, the combination of DES and solid-phase extraction (SPE) has broad application prospects. By virtue of their diverse functions, DESs have been used as eluents, in combination with a solid-phase extraction column and a stir bar, to elute analytes from the sorbent surface. The molar ratio of the HBA and HBD is one of the important factors influencing the elution efficiency. DESs can be combined with magnetic multiwalled carbon nanotubes, magnetic graphene oxide, and other nanocomposites to specifically adsorb target analytes through hydrogen bonding, π-π forces, and electrostatic forces. In addition, the DES can be used in the synthesis of magnetic nanocomposites and molecularly imprinted polymers when combined with magnetic materials. Magnetic nanocomposites functionalized with DES show excellent performance and high efficiency in the extraction process. The combination of DES and magnetic materials would promote the development of magnetic materials for green chemistry and expand the application of DES to several other fields. However, to the best of our knowledge, research on the microstructure, physical and chemical properties, and extraction mechanism of DESs is still in its nascent stage. Therefore, exploring the theoretical mechanism and applications of new DESs with special functions would be an essential future research direction. This article integrates the research progress of DESs in extraction separation technology; introduces the preparation, properties, and classification of DESs; and summarizes the applications of DESs in DLLME and SPE.

Editorial for the “Green Chemistry” Section in the Journal Molecules: Focus on Solvents

It is a pleasure to write this editorial highlighting some of the recent papers discussing solvents in the Green Chemistry section of Molecules [...]

Recovery and Stabilization of Anthocyanins and Phenolic Antioxidants of Roselle (Hibiscus sabdariffa L.) with Hydrophilic Deep Eutectic Solvents

Deep eutectic solvents (DESs) have got huge interest as new green and sustainable solvents for the extraction of bioactive compounds from plants in recent decades. In the present study, we aimed to investigate the effectiveness of hydrophilic DES for the extraction of anthocyanin and polyphenol antioxidants from Roselle. A natural hydrophilic DES constituted of sodium acetate (hydrogen bond acceptor) and formic acid (hydrogen bond donor) designed to evaluate the total phenolic compound (TPC), total flavonoid (TFC), total anthocyanin (TACN), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) values of Roselle. Distilled water, 70% ethanol, and 80% methanol used as conventional solvents for comparison. The results indicated that the DES prepared in molarity ratio (SAFAm) was the most efficient. Subsequently, this prominent DES selected for the optimization and the optimum extraction conditions were 1:3.6 molarity ratio, 0% additional water, and 10 mL solvent. TPC, TFC, TACN, FRAP, and DPPH radical scavenging at the optimum point were 233.26 mg GAE/g, 10.14 mg ECE/g, 10.62 mg D3S/g, 493.45 mmol ISE/g, and 343.41 mmol TE/g, respectively. The stability tests showed that anthocyanins were more stable in SAFAm. These findings revealed that SAFAm is an effective green solvent for the extraction of polyphenols from various plants.