Ultrasound-assisted surfactant-enhanced emulsification microextraction for the determination of carbamates in wines by ultra-high performance liquid chromatography–tandem mass spectrometry

In Silico Investigation of Selected Pesticides and Their Determination in Agricultural Products Using QuEChERS Methodology and HPLC-DAD

In this study, we considered some pesticides as active substances within formulations for the protection of plant-based food in the Republic of Serbia in silico, because these pesticides have not often been investigated in this way previously, and in an analytical way, because there are not very many available fast, cheap, and easy methods for their determination in real agricultural samples. Seven pesticides were detected in selected agricultural products (tomatoes, cucumbers, peppers, and grapes) using the QuEChERS methodology and HPLC-DAD. Standard curves for the investigated pesticides (chlorantraniliprole, methomyl, metalaxyl, thiacloprid, acetamiprid, emamectin benzoate, and cymoxanil) show good linearity, with R² values from 0.9785 to 0.9996. The HPLC-DAD method is fast, and these pesticides can be determined in real spiked samples in less than 15 min. We further characterized the pesticides we found in food based on physicochemical properties and molecular descriptors to predict the absorption, distribution, metabolism, elimination, and toxicity (ADMET) of the compounds. We summarized the data supporting their effects on humans using various computational tools to determine their potential adverse effects. The results of our prediction study show that all of the selected pesticides considered in this study have good oral bioavailability, and those with high toxicity, therefore, could be harmful to human health. Chlorantraniliprole was shown in a molecular docking study as a good starting point for a new Alzheimer's disease drug candidate.

Notifications on Pesticide Residues in the Rapid Alert System for Food and Feed (RASFF)

Pesticides are commonly used to protect plants against various pests and to preserve crops, but their residues can be harmful for human health. They are the third most widely reported hazard category in the European Rapid Alert System for Food and Feed (RASFF). The purpose of the study was to identify the most frequently notified pesticides in the RASFF in 1981–2020, considering: year, notification type, product category, origin country, notifying country, notification basis, distribution status and action taken. The data from the RASFF database was processed using: filtering, transposition, pivot tables and then subjected to cluster analysis: joining (tree clustering) and two-way joining methods. Pesticides were most commonly reported in fruits and vegetables and herbs and spices following border controls and rejections. The products usually came from India or Turkey and were not placed on the market or were not distributed and then destroyed. The effectiveness of the European Union border posts in terms of hazards detection and mutual information is important from the point of view of protecting the internal market and ensuring public health. It is also necessary to increase the awareness of pesticide users through training and the activity of control authorities in the use of pesticides.

Current overview and perspectives in environmentally friendly microextractions of carbamates and dithiocarbamates

Carbamates and dithiocarbamates are two classes of pesticides widely employed in the agriculture practice to control and avoid pests and weeds, hence, the monitoring of the residue of those pesticides in different foodstuff samples is important. Thus, this review presents the classification, chemical structure, use, and toxicology of them. Moreover, it was shown the evolution of liquid- and solid-phase microextractions employed in the extraction of carbamates and dithiocarbamates in water and foodstuff samples. The classification, operation mode, and application of the microextractions of liquid-phase and solid-phase used in their extraction were discussed and related to the analytical parameters and guidelines of green analytical chemistry.

A hierarchically porous composite monolith polypyrrole/octadecyl silica/graphene oxide/chitosan cryogel sorbent for the extraction and pre-concentration of carbamate pesticides in fruit juices

A hierarchically porous structured composite monolith sorbent of polypyrrole-coated graphene oxide and octadecyl silica incorporated in chitosan cryogel (PPY/GOx/C18/chitosan) was synthesized and used as solid-phase extraction sorbent for the determination of carbamate pesticides. Various factors affecting the characteristics of the adsorbents (chemistry of the sorbent, polymerization time, concentrations of graphene oxide and octadecyl silica) and the extraction efficiency using the prepared sorbents, such as sample loading, desorption conditions, sample volume, sample flow rate, sample pH, and ionic strength, were investigated and optimized. Under the optimal conditions of sorbent preparation and extraction, the developed composite monolith sorbent provided wide linear responses from 1.0 to 500 μg L^-1 for carbofuran and diethofencarb, from 0.5 to 500 μg L^-1 for carbaryl, and from 2.0 to 500 μg L^-1 for isoprocarb. The limits of detection using HPLC-UV at 203, 220, and 208 nm were in the range of 0.5-2.0 μg L^-1. When the composite monolith sorbent was applied for the pre-concentration and determination of carbamate in fruit juices, good recoveries (84.1-99.5%) were achieved. The developed sorbents were porous and exhibited low back pressure enabling their use at high flow rates during sample loading. Extraction and clean-up were highly efficient, and the good physical and chemical stability of the sorbent enables reuse up to 13 times. Graphical abstract ᅟ.

A simple solvent based microextraction for high performance liquid chromatographic analysis of aflatoxins in rice samples

This paper describes the development of a simple solvent based microextraction, namely vortex assisted low density solvent-microextraction (VALDS-ME), followed by high performance liquid chromatography-fluorescence detection (HPLC-FD) for the simultaneous determination of four aflatoxins (AFs) including AFB1, AFB2, AFG1 and AFG2 in rice samples. In VALDS-ME, a mixture of low density solvents (1-octanol and toluene) was used as the extraction solvent. The extraction was rapidly achieved with the assistance of vortex agitation and phase separation was easily obtained after the addition of Na₂SO₄. The effects of various parameters on the extraction efficiency were optimized. Under the optimum conditions, high enrichment factors (42-132), low limits of detection (LODs) in the range of 0.0011-0.17μgkg^-1 and good precisions (RSDs lower than 6.2%) were obtained. AFB1 and AFG1 were detected in berry rice sample at 0.26 and 2.1μgkg^-1, respectively. The recoveries in AFs-spiked rice samples ranged from 70% to 104%. Moreover, the present method was comparable to the conventional immunoaffinity chromatography method.

Evaluation of a new modified QuEChERS method for the monitoring of carbamate residues in high-fat cheeses by using UHPLC-MS/MS

A simple and efficient method for the determination of 28 carbamates in high-fat cheeses is proposed. The methodology is based on a modified quick, easy, cheap, effective, rugged, and safe procedure as sample treatment using a new sorbent (Z-Sep⁺ ) followed by ultra-high performance liquid chromatography with tandem mass spectrometry determination. The method has been validated in different kinds of cheese (Gorgonzola, Roquefort, and Camembert), achieving recoveries of 70-115%, relative standard deviations lower than 13% and limits of quantification lower than 5.4 μg/kg, below the maximum residue levels tolerated for these compounds by the European legislation. The matrix effect was lower than ±30% for all the studied pesticides. The combination of ultra-high performance liquid chromatography and tandem mass spectrometry with this modified quick, easy, cheap, effective, rugged, and safe procedure using Z-Sep⁺ allowed a high sample throughput and an efficient cleaning of extracts for the control of these residues in cheeses with a high fat content.

Vortex-Assisted Dispersive Micro-Solid Phase Extraction Using CTAB-Modified Zeolite NaY Sorbent Coupled with HPLC for the Determination of Carbamate Insecticides

A vortex-assisted dispersive micro-solid phase extraction (VA-D-μ-SPE) based on cetyltrimethylammonium bromide (CTAB)-modified zeolite NaY was developed for preconcentration of carbamate pesticides in fruits, vegetables, and natural surface water prior to analysis by high performance liquid chromatography with photodiode array detection. The small amounts of solid sorbent were dispersed in a sample solution, and extraction occurred by adsorption in a short time, which was accelerated by vortex agitation. Finally, the sorbents were filtered from the solution, and the analytes were subsequently desorbed using an appropriate solvent. Parameters affecting the VA-D-μ-SPE performance including sorbent amount, sample volume, desorption solvent ,and vortex time were optimized. Under the optimum condition, linear dynamic ranges were achieved between 0.004-24.000 mg kg(-1) (R(2) > 0.9946). The limits of detection (LODs) ranged from 0.004-4.000 mg kg(-1). The applicability of the developed procedure was successfully evaluated by the determination of the carbamate residues in fruits (dragon fruit, rambutan, and watermelon), vegetables (cabbage, cauliflower, and cucumber), and natural surface water.

Recent advances in application of liquid-based micro-extraction: A review

Liquid-based micro-extraction is a novel “green” sample preparation technique using micro-litre levels of organic solvent to extract target analytes from various sample matrices for subsequent instrumental analysis. This technique developed rapidly from its introduction in the mid-1990s. Micro-extraction methods can be conveniently combined with a wide selection of instruments commonly used in a chemical laboratory; they significantly reduce analysis time and costs of solvents’ use and waste disposal. This review focuses on recent advances in several liquid-based micro-extraction methods, including single-drop micro-extraction, hollow fibre-liquid phase micro-extraction, and dispersive liquid-liquid micro-extraction. Examples of application of these methods to environmental, food, and biomedical analysis are listed.