Two-phase hollow fiber liquid phase microextraction for preconcentration of pyrethroid pesticides residues in some fruits and vegetable juices prior to gas chromatography/mass spectrometry

Deep eutectic solvent as acceptor phase in three-phase hollow fiber liquid-phase microextraction for determination of pyrethroid insecticides from environmental water samples prior to HPLC

In this study, a deep eutectic solvent as acceptor phase was applied in three-phase hollow fiber liquid-phase microextraction (DES-HF-LPME) for the microextraction of two pyrethroids (Permethrin as well as deltamethrin) from environmental water samples prior to HPLC-UV. The deep eutectic solvent was synthesized of tetrabutylammonium bromide/decanoic acid (ratio of 1:2) as an acceptor phase, and 1-decanol was applied as a supported liquid membrane. Some main variables affecting the extraction recoveries, comprising the types/content of extraction solvent and acceptor phase, stirring speed, sample phase pH, and extraction time, were checked out and became optimal. In optimum circumstances, the detection limits and limits of quantitation determined were 0.09-0.12 μgL^-1 and 0.29-0.39 μgL^-1 for deltamethrin and permethrin, respectively. The enrichment factors were 627 and 613, while the relative standard deviations (RSD%, n=5) were calculated to be 4.8% and 5.7%, for deltamethrin and permethrin, respectively. The created technique was satisfyingly assessed to ascertain the two pyrethroid poisons (permethrin and deltamethrin) in environmental water samples.

Advancement and New Trends in Analysis of Pesticide Residues in Food: A Comprehensive Review

Food safety is a rising challenge worldwide due to the expanding population and the need to produce food to feed the growing population. At the same time, pesticide residues found in high concentrations in fresh agriculture pose a significant threat to food safety. Presently, crop output is being increased by applying herbicides, fungicides, insecticides, pesticides, fertilizers, nematicides, and soil amendments. A combination of factors, including bioaccumulation, widespread usage, selective toxicity, and stability, make pesticides among the most toxic compounds polluting the environment. They are especially harmful in vegetables and fruits because people are exposed to them. Thus, it is critical to monitor pesticide levels in fruits and vegetables using all analytical techniques available. Any evaluation of the condition of pesticide contamination in fruits and vegetables necessitates knowledge of maximum residue levels (MRLs). We set out the problems in determining various types of pesticides in vegetables and fruits, including the complexity and the diversity of matrices in biological materials. This review examines the different analytical techniques to determine the target analytes that must be isolated before final consumption. Many processes involved determining pesticide residues in fruits and vegetables and their advantages and disadvantages have been discussed with recommendations. Furthermore, MRLs of target pesticide residues in fruit and vegetable samples are discussed in the context of data from the literature. The review also examines MRLs' impact on the international trade of fruits and vegetables. Accurate, sensitive, and robust analytical procedures are critical to ensuring that pesticide levels in food products are effectively regulated. Despite advances in detection technology, effective sample preparation procedures for pesticide residue measurement in cereals and feedstuffs are still needed. In addition, these methods must be compatible with current analytical techniques. Multi-residue approaches that cover a wide range of pesticides are desired, even though pesticides' diverse natures, classes, and physio-chemical characteristics make such methods challenging to assemble. This review will be valuable to food analysts and regulatory authorities to monitor the quality and safety of fresh food products.

Solution decomposition of deep eutectic solvents in pH-induced solidification of floating organic droplet homogeneous liquid-liquid microextraction for the extraction of pyrethroid pesticides from milk

In this study, a pH-induced solidification of floating organic droplet homogeneous liquid-liquid microextraction procedure using deep eutectic solvent decomposition was developed for the extraction of five pyrethroid insecticides from milk samples prior to their analysis by using a gas chromatography-flame ionization detector. To reach this goal, the sample was transferred into a glass test tube and its proteins were precipitated with trichloroacetic acid. After centrifugation, the supernatant phase was transferred into another test tube and a few microliters of menthol: p-aminophenol deep eutectic solvent were dissolved in the solution and shaken to obtain a homogeneous solution. Then a few microliters of ammonia solution were added to the solution and the mixture was sonicated to break down the homogeneous solution. By doing so, the deep eutectic solvent was decomposed and menthol was formed throughout the solution as tiny droplets. In the following, the tube was transferred into an ice bath to solidify the extraction solvent on the solution surface. The collected phase was removed and melted at room temperature and an aliquot of it was analyzed by using a determination system. The validation outcomes confirmed that the method provides high extraction recoveries (72-84%) and high enrichment factors (257-299) with acceptable repeatability (relative standard deviations ≤6.4%). Low limits of detection (1.1-2.4 ng mL^-1) and quantification (3.6-8.1 ng mL^-1) were obtained using this approach. Finally, several milk samples were analyzed and deltamethrin was successfully determined in some samples.

Applications of Hollow-Fiber and Related Microextraction Techniques for the Determination of Pesticides in Environmental and Food Samples—A Mini Review

Pesticides represent one of the most important groups of analytes in environmental analysis. Moreover, their levels are very frequently determined in food and beverages due to the concern over their possible adverse health effects. Their concentration in samples is usually very low; thus, they have to be preconcentrated. Conventional solvent and solid-phase extractions are mainly used for this purpose, but miniaturized approaches are also being applied more and more often. The present review covers solvent microextractions that use a semi-permeable membrane barrier between the sample and the solvent. The main representatives of this approach are hollow-fiber microextraction (HFME), solvent bar microextraction (SBME), electromembrane extraction (EME), and different variations of those, such as combinations with other sorbent or solvent microextractions, electromigration, etc. The relevant research from the last decade, dealing with the application of these microextractions to the isolation of pesticides from various environmental and food samples, is critically discussed with emphasis on their strengths and weak points.

Magnetic mesoporous nanoparticles modified with poly(ionic liquids) with multi-functional groups for enrichment and determination of pyrethroid residues in apples

Considering that the determination of pyrethroid residues is of value for the safety of food, a new poly(ionic liquid)-functionalized magnetic mesoporous nanoparticle was designed and used as an adsorbent in magnetic solid-phase extraction for the enrichment of eight pyrethroids. The porous structure and large surface area of the mesoporous silica shell endow the adsorbent with abundant binding sites. In contrast to the reported poly(ionic liquids) with only one kind of functional group in the cationic part, the new poly(ionic liquids) with mixed cyano and phenyl groups in cationic part matched the chemical structure of the analytes to improve extraction efficiency. Under the optimum conditions, an effective method was established for the determination of eight pyrethroids in apples. Adsorption equilibrium can be quickly reached in 1 min, greatly decreasing the extraction time. The linearity range was found to be 10-200 ng/g, and the detection limits ranged from 0.24 to 1.99 ng/g. Recoveries of analytes in apple samples ranged from 87.3 to 119.0%, with relative standard deviations varying in the range of 3-21.2% (intraday) and 0.3-15.2% (interday). The results indicate that the proposed method is a good candidate for pyrethroid residues in apple samples.

Optimizing Mass Spectrometry Analyses: A Tailored Review on the Utility of Design of Experiments

Mass spectrometry (MS) has emerged as a tool that can analyze nearly all classes of molecules, with its scope rapidly expanding in the areas of post-translational modifications, MS instrumentation, and many others. Yet integration of novel analyte preparatory and purification methods with existing or novel mass spectrometers can introduce new challenges for MS sensitivity. The mechanisms that govern detection by MS are particularly complex and interdependent, including ionization efficiency, ion suppression, and transmission. Performance of both off-line and MS methods can be optimized separately or, when appropriate, simultaneously through statistical designs, broadly referred to as "design of experiments" (DOE). The following review provides a tutorial-like guide into the selection of DOE for MS experiments, the practices for modeling and optimization of response variables, and the available software tools that support DOE implementation in any laboratory. This review comes 3 years after the latest DOE review (Hibbert DB, 2012), which provided a comprehensive overview on the types of designs available and their statistical construction. Since that time, new classes of DOE, such as the definitive screening design, have emerged and new calls have been made for mass spectrometrists to adopt the practice. Rather than exhaustively cover all possible designs, we have highlighted the three most practical DOE classes available to mass spectrometrists. This review further differentiates itself by providing expert recommendations for experimental setup and defining DOE entirely in the context of three case-studies that highlight the utility of different designs to achieve different goals. A step-by-step tutorial is also provided.

Development of a dispersive liquid–liquid microextraction method based on solidification of a floating ionic liquid for extraction of carbamate pesticides from fruit juice and vegetable samples

In this work, a new sample preparation method based on solidification of an ionic liquid after performing dispersive liquid–liquid microextraction has been developed for the extraction and preconcentration of four carbamate pesticides.

In-syringe low-density ionic liquid dispersive liquid–liquid microextraction for the fast determination of pyrethroid insecticides in environmental water samples by HPLC-DAD

In-syringe low-density ionic liquid dispersive liquid–liquid microextraction.