Ionic liquid-linked dual magnetic microextraction: A novel and facile procedure for the determination of pyrethroids in honey samples

Optimization and validation of a fast supercritical fluid chromatography tandem mass spectrometry method for the quantitative determination of a large set of PFASs in food matrices and human milk

An Ultra-High Performance Supercritical Fluid Chromatography coupled with tandem Mass Spectrometry analytical method (UHPSFC-MS/MS) was developed for the determination of 34 perfluoroalkylated substances (PFASs) in food-related matrices. Two parameters (i.e. stationary phase and co-solvent) were selected and optimized using a step-by-step method, while a design of experiment (DoE) method using a central composite design (CCD) was implemented to optimize column temperature, mobile phase flow rate, co-solvent concentration and automated back pressure regulator (ABPR). The Torus 2-PIC column was selected along with ammonium acetate AcoNH₄ as additive in the co-solvent. DoE optimization of both peak width and resolution enabled validating an optimized model (desirability 0.613) and setting column temperature at 38.7 °C, AcoNH₄ concentration at 8 mM, mobile phase flow rate of 1.9 mL/min and ABPR at 1654 psi. The validated resulting method enabled reaching limits of quantification below 0.2 ng/g (w.w.) for 97 % PFASs in accordance with current EU requirements. The strategy was successfully applied to the characterization of a range (n > 30) of food-related matrices (red meat, poultry meat, eggs, fish and breast milk) collected in Algeria in 2019. PFOA and PFBA were observed as the most frequently detected PFASs, i.e. in 96.96 % and 90.9 % of the samples respectively. The highest concentrations were determined in fishery products up to 4.42 ng/g (w.w.) for PFTeDA and 0.75 ng/g (w.w.) for PFOS.

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.

Development of magnetic solid phase extraction using magnetic amphiphilic polymer for sensitive analysis of multi-pesticides residue in honey

A sensitive and time-saving method for the determination of multi-pesticide residues in honey was developed using magnetic solid phase extraction (MSPE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Magnetic polymer (N-vinyl pyrrolidone-divinyl benzene) (MVP-DB) was fabricated and employed as the adsorbent for extraction and enrichment of multi-pesticide residues in honey. MVP-DB contains lipophilic benzene ring, divinyl group, and hydrophilic pyrrolidone group. The good hydrophilic and hydrophobic structure of MVP-DB not only ensures sufficient dispersion in honey samples, but also enhances the ability to enrich target analytes. The predominant factors affecting the recoveries of analytes were systematically investigated, affording a rapid and highly efficient MSPE method. Under the optimal conditions, the method was verified, including the recovery, precision, linearity, sensitivity, and matrix effects. The results displayed that these pesticides showed good linearity in the range of 2-250 µg L^-1. The MLOQs were 0.5 µg kg^-1. The recoveries of pesticides in honey at the pre-spiked concentrations of 0.5-25 µg kg^-1 were 61.6%-112% with RSDs less than 18.2%. Hence, the developed method displayed good application prospect for the determination of multi-pesticide residues in honey samples.

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.

Separation and detection of cyproconazole enantiomers and its stereospecific recognition with chiral stationary phase by high-performance liquid chromatography

An optimal chiral analytical method of cyproconazole enantiomers was established based on BBD, and the stereospecific recognition mechanism was elucidated by docking.

The exposure of honey bees (Apis mellifera; Hymenoptera: Apidae) to pesticides: Room for improvement in research

Losses of honey bees have been repeatedly reported from many places worldwide. The widespread use of synthetic pesticides has led to concerns regarding their environmental fate and their effects on pollinators. Based on a standardised review, we report the use of a wide variety of honey bee matrices and sampling methods in the scientific papers studying pesticide exposure. Matrices such as beeswax and beebread were very little analysed despite their capacities for long-term pesticide storage. Moreover, bioavailability and transfer between in-hive matrices were poorly understood and explored. Many pesticides were studied but interactions between molecules or with other stressors were lacking. Sampling methods, targeted matrices and units of measure should have been, to some extent, standardised between publications to ease comparison and cross checking. Data on honey bee exposure to pesticides would have also benefit from the use of commercial formulations in experiments instead of active ingredients, with a special assessment of co-formulants (quantitative exposure and effects). Finally, the air matrix within the colony must be explored in order to complete current knowledge on honey bee pesticide exposure.

Liquid phase microextraction based on the solidification of a floating ionic liquid combined with high-performance liquid chromatography for the preconcentration of phthalate esters in environmental waters and in bottled beverages

Liquid-phase microextraction based on the solidification of floating ionic liquids.

Arsenic speciation analysis in environmental water, sediment and soil samples by magnetic ionic liquid-based air-assisted liquid–liquid microextraction

This highly efficient separation method combines the advantages of magnetic ionic liquid (MIL) and air-assisted liquid–liquid microextraction (AALLME) for the first time.

Response surface methodology for the enantioseparation of dinotefuran and its chiral metabolite in bee products and environmental samples by supercritical fluid chromatography/tandem mass spectrometry

Tracing the enantiomers of dinotefuran and its metabolite in bee products and relevant environmental matrices is vital because of the high toxicity of their racemates to bees. In this study, a statistical optimization strategy using three-dimensional response surface methodology for the enantioseparation of dinotefuran and its metabolite UF was developed by a novel supercritical fluid chromatography/tandem mass spectrometry (SFC-MS/MS) technique. After direct evaluation of the chromatographic variables - co-solvent content, mobile phase flow rate, automated backpressure regulator pressure (ABPR), and column temperature - involved in the separation mechanism and assessment of the interactions among these variables, the optimal SFC-MS/MS working conditions were selected as a CO2/2% formic acid-methanol mobile phase, 1.9mL/min flow rate, 2009.8psi ABPR, and 26.0°C column temperature using an amylose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase under electrospray ionization positive mode. Baseline resolution, favorable retention, and high sensitivity of the two pairs of enantiomers were achieved in pollen, honey, water, and soil matrices within 4.5min. Additionally, the parameters affecting the dispersive solid-phase extraction procedure, such as the type and content of extractant or purification sorbents, were systematically screened to obtain better extraction yields of the enantiomers. Mean recoveries were between 78.3% and 100.2% with relative standard deviations lower than 8.0% in all matrices. The limits of quantification ranged from 1.0μg/kg to 12.5μg/kg for the dinotefuran and UF enantiomers. Furthermore, the developed method was effectively applied to authentic samples from a market, an irrigation canal, and a trial field, and the enantioselective dissipation of dinotefuran and UF in soil was demonstrated.

Rapid ionic liquid-based ultrasound assisted dual magnetic microextraction to preconcentrate and separate cadmium-4-(2-thiazolylazo)-resorcinol complex from environmental and biological samples

A rapid and innovative microextraction technique named as, ionic liquid-based ultrasound-assisted dual magnetic microextraction (IL-UA-DMME) was developed for the preconcentration and extraction of trace cadmium from environmental and biological samples, prior to analyzed by flame atomic absorption spectrometry (FAAS). The proposed method has many obvious advantages, including evading the use of organic solvents and achieved high extraction yields by the combination of dispersive liquid-liquid microextraction (DLLME) and magnetic mediated-solid phase extraction (MM-SPE). In this approach ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] play an important role to extract the cadmium-4-(2-thiazolylazo)-resorcinol (Cd-TAR) complex from acid digested sample solutions and ultrasonic irradiation was applied to assist emulsification. After then, dispersed small amount of Fe3O4 magnetic nanoparticles (MNPs) in sample solutions to salvaged the IL and complete phase separation was attained. Some analytical parameters that influencing the efficiency of proposed (IL-UA-DMME) method, such as pH, volume of IL, ligand concentration, ultra-sonication time, amount of Fe3O4 MNPs, sample volume and matrix effect were optimized. Limit of detection (LOD) and enrichment factor (EF) of the method under optimal experimental conditions were found to be 0.40μgL(-1) and 100, respectively. The relative standard deviation (RSD) of 50μgL(-1) Cd was 4.29%. The validity and accuracy of proposed method, was assessed to analyzed certified reference materials of fortified lake water TMDA-54.4, SPS-WW2 waste water, spinach leaves 1570a and also checked by standard addition method. The obtained values showed good agreement with the certified values and sufficiently high recovery were found in the range of 98.1-101% for Cd. The proposed method was facile, rapid and successfully applied for the determination of Cd in environmental and different biological samples.

Magnetic solid-phase extraction based on Fe3O4nanoparticle retrieval of chitosan for the determination of flavonoids in biological samples coupled with high performance liquid chromatography

Schemes of two-step magnetic retrieval of chitosan and its application as MSPE adsorbents for simultaneous extraction and preconcentration of targeted analytes in urine and serum samples.