Physical assistive technologies of solid-phase microextraction: Recent trends and future perspectives

Nectarine core-derived magnetite biochar for ultrasound-assisted preconcentration of polycyclic aromatic hydrocarbons (PAHs) in tomato paste: A cost-effective and sustainable approach

A novel ultrasound-assisted magnetic solid-phase extraction coupled with gas chromatography-mass spectrometry (US-MSPE-GC/MS) was developed to detect trace amounts of polycyclic aromatic hydrocarbons (PAHs) in tomato paste, using a magnetic biochar adsorbent derived from nectarine cores. The highest extraction recovery was attained under 10 mg adsorbent mass, 30 min extraction time, 9 % (w/v) sodium chloride, and elution with 200 μL of dichloromethane. Under optimum conditions, the method demonstrated excellent linearity (R2 > 0.992) across a wide concentration range (0.01-100 ng g-1) with high sensitivity (LODs: 0.028-0.053 ng g-1, LOQs: 0.094-0.176 ng g-1) and good repeatability (RSDs <5.96 %). The application of the US-MSPE-GC/MS method was tested on four brands of real tomato paste and no PAHs were detected in unspiked samples, indicating no background contamination. This method showed high relative recoveries 88.03-98.52 %) and good reproducibility (<9.19 %.) at two concentration levels, confirming its effectiveness for PAH analysis in real 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.

Nanoscale Materials Applying for the Detection of Mycotoxins in Foods

Trace amounts of mycotoxins in food matrices have caused a very serious problem of food safety and have attracted widespread attention. Developing accurate, sensitive, rapid mycotoxin detection and control strategies adapted to the complex matrices of food is crucial for in safeguarding public health. With the continuous development of nanotechnology and materials science, various nanoscale materials have been developed for the purification of complex food matrices or for providing response signals to achieve the accurate and rapid detection of various mycotoxins in food products. This article reviews and summarizes recent research (from 2018 to 2023) on new strategies and methods for the accurate or rapid detection of mold toxins in food samples using nanoscale materials. It places particular emphasis on outlining the characteristics of various nanoscale or nanostructural materials and their roles in the process of detecting mycotoxins. The aim of this paper is to promote the in-depth research and application of various nanoscale or structured materials and to provide guidance and reference for the development of strategies for the detection and control of mycotoxin contamination in complex matrices of food.

Novel electrochemical sensing platform basing on di-functional stimuli-responsive imprinted polymers for simultaneous extraction and determination of metronidazole

A novel magnetic-controlled electrochemical sensor has been fabricated by combined photo-responsive surface molecular imprinted polymers (P-SMIPs) and electrochemical sensor. In particular, the P-SMIPs were obtained by living radical polymerization of photo-responsive functional monomer onto the magnetic Fe₃O₄ modified multi-walled carbon nanotubes nanocomposites. The magnetic glassy carbon electrode was introduced to make the anchoring and removal of P-SMIPs onto the magnetic-controlled glassy carbon electrode easy to manipulate. Driven by UV/vis light, the platform performs releasing and absorption of metronidazole basing on conformational variations of the photo-responsive monomer at the receptor sites part in the P-SMIPs. This process can be tested by the photo-responsive variations of metronidazole electrochemical signal. As the consequence, extracting of P-SMIPs sensor can be conveniently triggered by the controllable UV light intervention measure, leading to effectively improve in both analytes mass transfer rate to the receiving media and extraction efficiency. The experimental result indicated that the excellent recoveries of metronidazole were varied between 77.9% and 89.9% with RSDs ≤4.87% in the biological samples. Therefore, the P-SMIPs sensor shows satisfactory potential in reusable extractions that can be recycled several times with no significant loss of activity, and this utilization strategy can be extended to other analytes, achieving manifold applications of pharmaceutical and environmental.

Cavitation-Effect-Based Treatments and Extractions for Superior Fruit and Milk Valorisation

Ultrasound generates cavities in liquids with high-energy behaviour due to large pressure variations, leading to (bio)chemical effects and material modification. Numerous cavity-based treatments in food processes have been reported, but the transition from research to industrial applications is hampered by specific engineering factors, such as the combination of several ultrasound sources, more powerful wave generators or tank geometry. The challenges and development of cavity-based treatments developed for the food industry are reviewed with examples limited to two representative raw materials (fruit and milk) with significantly different properties. Both active compound extraction and food processing techniques based on ultrasound are taken into consideration.

Dynamic SPME-SERS Induced by Electric Field: Toward In Situ Monitoring of Pharmaceuticals and Personal Care Products

The core of the surface-enhanced Raman spectroscopy (SERS)-based techniques for dynamic monitoring is to realize rapid and reversible adsorption. Herein, the integration technology of electro-enhanced adsorption, solid-phase microextraction, and surface-enhanced Raman spectroscopy (EE-SPME-SERS) was developed to obtain sensitive, ultrafast, and reversible SERS response toward in situ monitoring of pharmaceuticals and personal care products (PPCPs). In the EE-SPME-SERS method, a roughened Ag fiber with Au modification (r-Ag/Au fiber) was used as the SERS substrate, SPME sorbent, and working electrode. The r-Ag/Au fiber displayed good SERS sensitivity, ultrahigh photostability, and adsorption properties. The adsorption efficiency of benzidine was 76 times accelerated in EE-SPME-SERS compared to that in static adsorption. The whole process of "sampling and detection" in EE-SPME-SERS can be finished within 1 s. Reversible adsorption and desorption can be achieved in situ by switching the direction of electric field, and the regeneration process takes only a few minutes. Simulated release of benzidine from household wastewater was in situ and dynamically monitored using this strategy. EE-SPME-SERS was proved universal for ionized PPCPs and can detect multicomponents simultaneously. In addition, EE-SPME-SERS showed very good analytical properties. Great potential of EE-SPME-SERS can be expected in environmental monitoring.

Current Sample Preparation Methodologies for Determination of Catecholamines and Their Metabolites

Catecholamines (CAs) and their metabolites play significant roles in many physiological processes. Changes in CAs concentration in vivo can serve as potential indicators for the diagnosis of several diseases such as pheochromocytoma and paraganglioma. Thus, the accurate quantification of CAs and their metabolites in biological samples is quite important and has attracted great research interest. However, due to their extremely low concentrations and numerous co-existing biological interferences, direct analysis of these endogenous compounds often suffers from severe difficulties. Employing suitable sample preparation techniques before instrument detection to enrich the target analytes and remove the interferences is a practicable and straightforward approach. To date, many sample preparation techniques such as solid-phase extraction (SPE), and liquid-liquid extraction (LLE) have been utilized to extract CAs and their metabolites from various biological samples. More recently, several modern techniques such as solid-phase microextraction (SPME), liquid-liquid microextraction (LLME), dispersive solid-phase extraction (DSPE), and chemical derivatizations have also been used with certain advanced features of automation and miniaturization. There are no review articles with the emphasis on sample preparations for the determination of catecholamine neurotransmitters in biological samples. Thus, this review aims to summarize recent progress and advances from 2015 to 2021, with emphasis on the sample preparation techniques combined with separation-based detection methods such capillary electrophoresis (CE) or liquid chromatography (LC) with various detectors. The current review manuscript would be helpful for the researchers with their research interests in diagnostic analysis and biological systems to choose suitable sample pretreatment and detection methods.

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.

Fabrication of Co3O4 quantum dot incorporated polyacrylamide ethylene glycol dimethacrylate as a new fiber for solid phase microextraction and trace determination of organophosphorus pesticides in environmental water samples

In this paper, a novel solid phase microextraction fiber based on Co₃O₄ quantum dot incorporated polyacrylamide-co-ethylene glycol dimethacrylate followed by corona discharge ion mobility spectrometry is presented for the trace determination of organophosphorus pesticides in environmental water samples. Ion mobility spectrometry is a comparatively inexpensive, well-known, robust, and easy to operate analytical instrument. This combination would provide a low-cost, fast, selective, and sensitive quantitative system for detection of organophosphorus pesticides. In order to obtain the best extraction efficiency, the optimization of parameters affecting this method was carried out. After optimization, a solution pH of 7.0, extraction temperature of 60 °C, adsorption temperature of 260 °C, extraction time of 30 min, stirring speed of 750 rpm, and ionic strength of 10% w/w were obtained. Consequently, the presented method showed low limits of detection (0.3-0.6 ng mL^-1), excellent enrichment factors (PF = 221-263), good linearity (R² > 0.995), and repeatabilities (intra-day: 3.4 to 4.8%) and (inter-day: 4.7 to 6.1%). The reproducibility (RSD% of fiber to fiber) was also investigated by analyzing three as-prepared fibers under the same conditions and was found to be less than 7.6%. Finally, the developed fiber was used for determination of organophosphorus pesticides in the field samples.