Ultrasound-assisted dispersive liquid-liquid microextraction followed by ion mobility spectrometry for the simultaneous determination of bendiocarb and azinphos-ethyl in water, soil, food and beverage samples

Deep eutectic solvents as a green alternative for trace element analysis in food and beverage samples: Recent advances and challenges

Metals and metalloids have different effects on human health even at trace levels. Some of them are essential for living organisms while others can be toxic. Therefore, the determination of trace elements in food and beverage is highly important to understand their impact in human health. A new generation of solvents named deep eutectic solvents (DES) has emerged as a green alternative for trace element analysis, owing to their low toxicity, biodegradability, and high extraction capacity. In recent years, the application of DES in extraction techniques for trace element analysis in food and beverage samples has increased significantly. This review summarizes recent advances and challenges on the application of DES to develop microextraction techniques useful for the analysis of samples with complex matrices. The importance of the use of biodegradable substances instead of classic organic solvents, which are toxic, volatile, and flammable in methods for elemental analysis with a positive environmental impact is also highlighted. Finally, conclusions and future challenges arising from the use of DES in microextraction techniques are discussed.

Drug repurposing strategy II: from approved drugs to agri-fungicide leads

Epidemic diseases of crops caused by fungi deeply affected the course of human history and processed a major restriction on social and economic development. However, with the enormous misuse of existing antimicrobial drugs, an increasing number of fungi have developed serious resistance to them, making the diseases caused by pathogenic fungi even more challenging to control. Drug repurposing is an attractive alternative, it requires less time and investment in the drug development process than traditional R&D strategies. In this work, we screened 600 existing commercially available drugs, some of which had previously unknown activity against pathogenic fungi. From the primary screen at a fixed concentration of 100 μg/mL, 120, 162, 167, 85, 102, and 82 drugs were found to be effective against Rhizoctonia solani, Sclerotinia sclerotiorum, Botrytis cinerea, Phytophthora capsici, Fusarium graminearum and Fusarium oxysporum, respectively. They were divided into nine groups lead compounds, including quinoline alkaloids, benzimidazoles/carbamate esters, azoles, isothiazoles, pyrimidines, pyridines, piperidines/piperazines, ionic liquids and miscellaneous group, and simple structure-activity relationship analysis was carried out. Comparison with fungicides to identify the most promising drugs or lead structures for the development of new antifungal agents in agriculture.

Smartphone-based colorimetric determination of triclosan in aqueoussamples after ultrasound assisted-dispersive liquid-liquid microextraction under optimized response surface method conditions

In the present study, a simple and low cost methodology based on ultrasonic assisted-dispersive liquid-liquid microextraction (UA-DLLME) followed by smartphone-based colorimetric measurement was introduced for the separation and determination of Triclosan (TCS) from contaminated waters. This method is based on the formation of an azo compound from the alkaline reaction of TCS with a diazonium ion, resulting from the reaction of sodium nitrite and p-sulfanilic acid in an acidic medium. The orange-brown color product was extracted into a low volume of organic phase by UA-DLLME method and RGB values were recorded with free Android app Color Grab. The effective parameters in this procedure, namely solution pH, p-sulfanilic acid and nitrite concentration, reaction time and volume of the extraction solvent were investigated and optimized by response surface methodology (RSM) based on a Box-Behnken design (BBD) model. Under optimum conditions, the calibration graph was linear in the range of 3.0 and 200 μg L^-1 of TCS. The limit of detection (LOD) and limit of quantification (LOQ) were 0.8 and 2.7 μg L^-1, respectively. The proposed method was successfullyused for the analyses of triclosan in several water and wastewater samples and satisfactory results were obtained.

Synthesis and application of new silver and sulfur decorated S-doped reduced graphene oxide in ultra-trace analysis of pesticides by ion mobility spectrometry

In this research study, a novel, facile, and affordable method is presented for the synthesis of a Ag/S/S-RGO nanocomposite. The resulting new nanocomposite was identified by FT-IR, XRD, FESEM, XPS, BET and EDX and employed as a rapid and effective adsorbent with acceptable absorption capacity for the analysis of various pesticides by dispersive solid-phase microextraction combined with ion mobility spectrometry. The main experimental parameters of the method were optimized such as the type of desorption solvent, pH of the sample solution, type of buffer, amount of the sorbent (Ag/S/S-RGO), sorption/desorption time, etc. Under the optimized conditions, linear dynamic ranges of 0.5-110.0, 1.0-110.0, and 0.8-90.0 ng mL^-1 were achieved, with limits of detection of 0.25, 0.35, and 0.25 ng mL^-1 for simazine, alachlor, and haloxyfop, respectively. The relative standard deviations (RSD%) were obtained as <5.0%. Eventually, the method was utilized for the simultaneous determination of simazine, alachlor, and haloxyfop in environmental and agricultural samples with recoveries between 95.0 and 104.6%.

QuEChERS-based analytical methods developed for LC-MS/MS multiresidue determination of pesticides in representative crop fatty matrices: Olives and sunflower seeds

Oilseed crops are greatly extended all over the world. Their high fat content can interfere during pesticide multiresidue analysis through liquid chromatography-tandem mass spectrometry (LC-MS/MS). This work aimed at overcoming this issue by developing and validating two QuEChERS-based methods for LC-MS/MS determination of 42 pesticides in two fatty food matrices: olives and sunflower seeds. Optimization of the extraction method was achieved following a 2^6-2 fractional factorial design in a highly cost-effective way. Validation of the multi-residue methods demonstrated improved limits of detection, below the established maximum residue levels (MRLs) for almost all compounds, good precision, and trueness, in compliance with SANTE guidelines. Application of these methods to the analysis of real samples from the Iberian Peninsula showed the presence of some pesticides of relevant environmental concern, including four compounds contained in the Pesticide Action Network International list of highly hazardous pesticides, found at levels between 0.03 ng/g and 104 ng/g.

Green Extraction Techniques as Advanced Sample Preparation Approaches in Biological, Food, and Environmental Matrices: A Review

Green extraction techniques (GreETs) emerged in the last decade as greener and sustainable alternatives to classical sample preparation procedures aiming to improve the selectivity and sensitivity of analytical methods, simultaneously reducing the deleterious side effects of classical extraction techniques (CETs) for both the operator and the environment. The implementation of improved processes that overcome the main constraints of classical methods in terms of efficiency and ability to minimize or eliminate the use and generation of harmful substances will promote more efficient use of energy and resources in close association with the principles supporting the concept of green chemistry. The current review aims to update the state of the art of some cutting-edge GreETs developed and implemented in recent years focusing on the improvement of the main analytical features, practical aspects, and relevant applications in the biological, food, and environmental fields. Approaches to improve and accelerate the extraction efficiency and to lower solvent consumption, including sorbent-based techniques, such as solid-phase microextraction (SPME) and fabric-phase sorbent extraction (FPSE), and solvent-based techniques (μQuEChERS; micro quick, easy, cheap, effective, rugged, and safe), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), in addition to supercritical fluid extraction (SFE) and pressurized solvent extraction (PSE), are highlighted.

Preparation of magnetic molecularly imprinted polymer based on multiwalled carbon nanotubes for selective dispersive micro-solid phase extraction of fenitrothion followed by ion mobility spectrometry analysis

A novel molecularly imprinted polymer based on magnetic multi-walled carbon nanotubes was fabricated and applied for selective dispersive micro-solid phase extraction of fenitrothion prior its determination by ion mobility spectrometry. The composite was synthesized using magnetic multi-walled carbon nanotubes as the support. Methacrylic acid was used as the functional monomer, fenitrothion as the template, ethylene glycol dimethacrylate as the cross-linker and 2,2-azoisobutyronitrile as the initiator. The resultant polymer was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, Brunauer-Emmet-Teller analysis, thermogravimetric analysis and vibrating sample magnetometer techniques. Experimental factors affecting the extraction efficiency such as pH and amount of sorbent were evaluated. Under optimum experimental conditions, the developed method displayed the linear range of 5-220 μg L^-1 with a detection limit (LOD) of 1.3 μg L^-1 . The intra and inter-day relative standard deviations (RSD%) for determination of fenitrothion were 3.6 and 4.7% (n = 6), respectively. Ultimately, the proposed method was used to monitoring of trace amounts of fenitrothion in fruit,vegetable and water samples. This article is protected by copyright. All rights reserved.

Application of ZnS/S/S-RGO three-component nanocomposites in dispersive solid-phase microextraction coupled with ion mobility spectrometry for ultra-trace determination of multiclass pesticides

A fast, effective, and sensitive dispersive solid-phase microextraction method coupled with ion mobility spectrometry for the simultaneous determination of bendiocarb, butachlor, and diazinon was developed using zinc sulfide/sulfur/sulfur-doped reduced graphene oxide (ZnS/S/S-RGO) nanocomposites. ZnS/S/S-RGO three-component nanocomposites were synthesized through a single-step solvothermal procedure, and their properties were characterized by FT-IR, XRD, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and energy-dispersive x-ray spectroscopy (EDX). The influence of different parameters was optimized on the efficiency of the extraction including the type and the volume of desorption solvent, pH, type and the volume of buffer, the amount of absorbent, sorption and  desorption times. Under the optimal conditions, linear ranges were achieved 0.8-110, 1.0-110, and 0.5-100 ng mL^-1 with detection limits of 0.32±0.01, 0.40±0.02, and 0.27±0.02 ng mL^-1 for bendiocarb, butachlor, and diazinon, respectively. The method was employed for the ultra-trace determination of the three pesticides in water, rice, and soil samples with acceptable recovery values within the range 96.6±4.8-104.4±6.4%.

Miniaturized sample preparation techniques and ambient mass spectrometry as approaches for food residue analysis

Analytical methods such as liquid chromatography (LC) and mass spectrometry (MS) are widely used techniques for the analyses of different classes of compounds. This is due to their highlighted capacity for separating and identifying components in complex matrices such food samples. However, in most cases, effective analysis of the target analyte becomes challenging due to the complexity of the sample, especially for quantification of trace concentrations. In this case, miniaturized sample preparation methods have been used as a strategy for analysis of complex matrices. This involves removing the interferents and concentrating the analytes in a sample. These methods combine simplicity and effectiveness and given their miniaturized scale, they are in accordance with green chemistry precepts. Besides, ambient mass spectrometry represents a new trend in fast and rapid analyses, especially for qualitative and screening analysis. However, for complex matrix analyses, sample preparation is still a difficult step and the miniaturized sample preparation techniques show great potential for an improved and widespread use of ambient mass spectrometry techniques. . This review aims to contribute as an overview of current miniaturized sample preparation techniques and ambient mass spectrometry methods as different approaches for selective and sensitive analysis of residues in food samples.

Deep eutectic solvent-based dispersive liquid-liquid micro-extraction of pesticides in food samples

Deep eutectic solvents are versatile, green and new generation solvents that can be used during dispersive liquid-liquid micro-extraction techniques for pesticides. They have tunable physico-chemical properties that can be easily changed by varying the ratios of hydrogen bond donors and hydrogen bond acceptors in their structures. Deep eutectic solvents are non-flammable, chemically and thermally stable solvents with low vapour pressure. Thus, they have characteristics that are similar to those of ionic liquids. However, they have simpler synthetic procedures, less expensive and are more biodegradable than ionic liquids. One of the limitations of deep eutectic solvents is their toxicity to the environment but they are less toxic than ionic liquids. This paper gives a focused and comprehensive recent review on the applications of deep eutectic solvents during dispersive liquid-liquid micro-extraction of pesticides in food samples for the period starting from 2016 to 2020. Emphasis was placed on the modifications done to the deep eutectic solvent-based dispersive liquid-liquid micro-extraction techniques in order to enhance their greenness during pesticide pre-concentration in food samples. In addition, hyphenated dispersive liquid-liquid micro-extraction techniques were also reviewed and lastly, the paper outlined the challenges associated with the use of DESs during the DLLME techniques.

Impact of pesticide polarity and lipid phase dimensions on the bioaccessibility of pesticides in agricultural produce consumed with model fatty foods

For most people, the pesticide residues found on agriculture products are the main source of pesticide exposure, which may adversely influence consumer health. The potential health hazard of residual pesticides depends on the nature of the foods they are consumed with. Studies with fat-soluble vitamins and nutraceuticals have shown that their bioaccessibility depends on food matrix composition and structure. We used an in vitro method to investigate the influence of the dimensions of the lipid phase in model fatty foods (emulsified or bulk oil) on the bioaccessibility of various pesticides. Three pesticides that differed in their oil-water partition coefficients were selected: bendiocarb (log P = 1.7), parathion (log P = 3.8), and chlorpyrifos (log P = 5.3). These pesticides were mixed with tomato puree to represent pesticide-treated agricultural products. Three model foods with different oil phase dimensions were used to represent different kinds of food product: small emulsions (d32 = 0.14 μm); large emulsions (d32 = 10 μm); and, bulk oil. Our results showed that the oil droplets underwent extensive changes as they passed through the simulated gastrointestinal tract due to changes in environmental conditions, such as pH, ionic strength, bile salts, and enzyme activities. The initial rate and final amount of lipid hydrolysis decreased with increasing lipid phase dimensions. Pesticide bioaccessibility depended on both the hydrophobicity of the pesticide and the dimensions of the co-ingested lipid droplets. The least hydrophobic pesticide (bendiocarb) had a high bioaccessibility (>95%) that did not depend on lipid phase dimensions. The more hydrophobic pesticides (parathion and chlorpyrifos) has a lower bioaccessibility that increased with decreasing lipid phase dimensions. Our results demonstrate the critical role that food structure plays on the potential uptake of pesticides from agricultural products, like fruits and vegetables.

Recent nano-, micro- and macrotechnological applications of ultrasonication in food-based systems

There is a neoteric and rising demand for nutritional and functional foods which behooves food processors to adopt processing techniques with optimal conservation of bioactive components in foods and with minimal pernicious impacts on the environment. Ultrasonication, a mechanochemical technique has proven to be an efficacious panacea to these concerns. In this review, an analytic exploration of recent researches and designs regarding ultrasound methodology and equipment on diverse food systems, technological scales, procedural parameters and outcomes of such experimentations optimally scrutinized. The relative effects of ultrasonication on food formulations, components and attributes such as nanoemulsions, nanocapsules, proteins, micronutrients, sensory and mechanical characteristics are evaluatively delineated. In food systems where ultrasonication was employed, it was found to have a remarkable effect on one or more quality parameters. This review is a supplementation to the pedagogical awareness to scholars on the suitability of ultrasonication for research procedures, and a call to industrial food brands on the adoption of this technique for the development of foods with optimally sustained nutrient profiles.

Impact of Pesticide Type and Emulsion Fat Content on the Bioaccessibility of Pesticides in Natural Products

There is interest in incorporating nanoemulsions into certain foods and beverages, including dips, dressings, drinks, spreads, and sauces, due to their potentially beneficial attributes. In particular, excipient nanoemulsions can enhance the bioavailability of nutraceuticals in fruit- and vegetable-containing products consumed with them. There is, however, potential for them to also raise the bioavailability of undesirable substances found in these products, such as pesticides. In this research, we studied the impact of excipient nanoemulsions on the bioaccessibility of pesticide-treated tomatoes. We hypothesized that the propensity for nanoemulsions to raise pesticide bioaccessibility would depend on the polarity of the pesticide molecules. Bendiocarb, parathion, and chlorpyrifos were therefore selected because they have Log P values of 1.7, 3.8, and 5.3, respectively. Nanoemulsions with different oil contents (0%, 4%, and 8%) were fabricated to study their impact on pesticide uptake. In the absence of oil, the bioaccessibility increased with increasing pesticide polarity (decreasing Log P): bendiocarb (92.9%) > parathion (16.4%) > chlorpyrifos (2.8%). Bendiocarb bioaccessibility did not depend on the oil content of the nanoemulsions, which was attributed to its relatively high water-solubility. Conversely, the bioaccessibility of the more hydrophobic pesticides (parathion and chlorpyrifos) increased with increasing oil content. For instance, for chlorpyrifos, the bioaccessibility was 2.8%, 47.0%, and 70.7% at 0%, 4%, and 8% oil content, respectively. Our findings have repercussions for the utilization of nanoemulsions as excipient foods in products that may have high levels of undesirable non-polar substances, such as pesticides.