Review of geometries and coating materials in solid phase microextraction: Opportunities, limitations, and future perspectives

Evaluation of thin film microextraction based on graphene oxide/ polymer composite: Experimental and theoretical insights

Experimental and theoretical assessments of a graphene oxide-based polymer as adsorbent for thin film microextraction (TFME) were conducted as part of this research. Graphene oxide (GO) was embedded in the organic polymer poly(styrene-co-divinylbenzene) (PS-DVB) to prepare a sorbent suitable for direct-immersion TFME. A TFME membrane coating prepared with the GO/PS-DVB sorbent and polydimethylsiloxane (PDMS) as binder was then applied for extraction of organic pollutants from aqueous and gaseous samples. The surface morphology of the TFME coating was examined by scanning electron microscopy (SEM). Various TFME parameters influencing extraction efficiency, such as extraction time and temperature, desorption temperature, and ionic strength, were investigated and optimized. In a comparison of TFME membranes, the GO/PS-DVB/PDMS TFME membrane was shown to yield higher extraction efficiencies for the targeted analytes than the pure PDMS and DVB/PDMS TFME membranes. The calibration graphs of the organic pollutants displayed linearity for most of the target analytes within the 10-2000 ng L-1 concentration range. The repeatability (RSD %, n = 5) and reproducibility (RSD %, n = 3) of the method were in the ranges of 2.2-5.9 %, and 3.2-8.5 %, respectively, at a concentration level of 500 ng L-1, whereas accuracy (%) ranged between 79.8 and 119 %. The developed method was successfully applied for determinations of organic pollutants in tap water, lake water, and wastewater samples. Furthermore, the impact of mass transfer kinetics on extractions by the GO/PS-DVB/PDMS TFME membrane from gaseous samples was theoretically discussed and experimentally verified. The results of this work demonstrate that the GO/PS-DVB/PDMS TFME method is a simple, efficient, and environmentally friendly method for pre-treatment of organic pollutants.

Incorporation of Cu-TATAB metal-organic framework within polyurethane nanocomposite for enhanced thin film microextraction of some chlorinated pesticides

In this research, electrospun nanofibers based on copper-based metal organic framework (MOF)/polyurethane (PU) were prepared in order to achieve an applicable and superior extractive phase. The incorporation of MOF, in the synthesized nanocomposite contributed to the enhanced sorption efficiency. The prepared sorbent was implemented for the thin film microextraction (TFME) of target compounds with subsequent quantification using gas chromatography-mass spectrometry (GC-MS). To obtain the maximum efficiency of the synthesized sorbent, the influential parameters on extraction and desorption steps, including the MOF percentage in nanocomposite, desorption solvent type and its volume, desorption time, solution ionic strength and extraction time were optimized. After method development, the linear dynamic range (0.02-700 μg L-1), limits of detection (LODs) (0.005-0.1 μg L-1) and limits of quantification (LOQs))0.02-0.33 μg L-1(were calculated. The relative standard deviations values for intra-day and inter-day analysis were found to be in the range of 4.3-5.3 % and 6.2-8.1 %, respectively. The developed method was validated for the TFME of model organochlorine (OC) pesticide residues in fish, soil and water samples. the recovery values for the spiked samples at two concentration levels of 5 and 100 µg l-1 were found in the range of 72-110 %.

Supramolecular Materials as Solid-Phase Microextraction Coatings in Environmental Analysis

Solid-phase microextraction (SPME) has been widely proposed for the extraction, clean-up, and preconcentration of analytes of environmental concern. Enrichment capabilities, preconcentration efficiency, sample throughput, and selectivity in extracting target compounds greatly depend on the materials used as SPME coatings. Supramolecular materials have emerged as promising porous coatings to be used for the extraction of target compounds due to their unique selectivity, three-dimensional framework, flexible design, and possibility to promote the interaction between the analytes and the coating by means of multiple oriented functional groups. The present review will cover the state of the art of the last 5 years related to SPME coatings based on metal organic frameworks (MOFs), covalent organic frameworks (COFs), and supramolecular macrocycles used for environmental applications.

Solid-phase microextraction - a future technique in pharmacology and coating trends

Traditional sample preparation techniques based on liquid-liquid extraction (LLE) or solid-phase extraction (SPE) often suffer from a major error due to the matrix effects caused by significant co-extraction of matrix components. The implementation of a modern extraction technique such as solid-phase microextraction (SPME) was aimed at reducing analysis time and the use of organic solvents, as well as eliminating pre-analytical and analytical errors. Solid-phase microextraction (SPME) is an innovative technique for extracting low molecular weight compounds (less than 1500 Da) from highly complex matrices, including biological matrices. It has a wide range of applications in various types of analysis including pharmaceutical, clinical, metabolomics and proteomics. SPME has a number of advantages over other extraction techniques. Among the most important are low environmental impact, the ability to sample and preconcentrate analytes in one step, simple automation, and the ability to extract multiple analytes simultaneously. It is expected to become, in the future, another method for cell cycle research. Numerous available literature sources prove that solid-phase microextraction can be a future technique in many scientific fields, including pharmaceutical sciences. This paper provides a literature review of trends in SPME coatings and pharmacological applications.

Controlled construction of 2D hierarchical core-shell ZnO/MnO2 nanosheets on Nitinol fiber with enhanced adsorption performance for selective solid-phase microextraction of trace polycyclic aromatic hydrocarbons in water samples

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are an important class of potentially toxic persistent organic pollutants in environmental water. Their concentrations are usually too low to allow for direct determination with analytical instruments, and the preconcentration is required prior to instrumental analysis. Solid phase microextraction (SPME) is considered as a high-performance green sample preparation technique for volatile and non-volatile organic compounds due to its high enrichment factor. In fact, the nature of SPME coatings governs the adsorption performance. Therefore, more efforts have devoted to the controlled construction of novel long-life SPME fibers with enhanced adsorption performance and improved adsorption selectivity.

RESULTS

2D hierarchical core-shell ZnO/MnO2 nanosheets (NSs) were constructed on a Nitinol (NiTi) fiber substrate by layer-by-layer assembly for enhanced and selective SPME of PAHs. Firstly, hexagonal ZnO NSs were electrodeposited on the NiTi substrate. Subsequently smaller secondary MnO2 NSs were uniformly grown on the surface of ZnO NSs by a facile hydrothermal oxidation process. ZnO NSs were well protected by the chemically stable MnO2 shell, making the coating highly durable and efficient for SPME application. Meanwhile, the ZnO/MnO2 NSs coating demonstrated superior adsorption performance for PAHs. After the optimization of SPME conditions, the proposed SPME-HPLC-UV method exhibited good analytical performance for preconcentrating and determining trace PAHs with wide linear ranges (0.03-200 μg L-1) and low LODs (0.005-0.112 μg L-1) as well as good repeatability (1.4%-6.9%) and fiber-to-fiber reproducibility (5.3%-7.1%). Moreover, the proposed method showed good precision and recovery in the preconcentration and determination of target PAHs in real water samples.

SIGNIFICANCE

As compared with representative commercially available fibers, the NiTi@ZnO/MnO2 NSs fiber showed enhanced adsorption efficiency and improved adsorption selectivity for PAHs. The constructed fiber can be used as an alternative to commercial fibers for the adsorption and preconcentration of target PAHs in the environmental water samples. Moreover, the preparation strategy is expected to provide new insights into the precisely controlled construction of the efficient and stable core-shell bimetallic oxide nanostructures on the superielastic NiTi-based fibers.

A novel top-down strategy for in situ construction of vertically oriented hexagonal NiCr LDHs nanosheet arrays with intercalated sulfate ions on Nichrome fiber for selective solid-phase microextraction of phenolic compounds in water samples

BACKGROUND

Phenolic compounds (PCs) are a class of polar aromatic pollutants with high toxicity in environmental water. Generally the efficient sample preparation is essential for the quantification of ultra-trace target PCs in real water sample before appropriative instrumental analysis. SPME is a convenient, solvent-free and time-saving miniaturized technique and has been recognized as a green alternative to conventional extraction techniques. In SPME, however, commercial fused-silica fibers are limited to the fragility, operation temperature, extraction capacity and selectivity as well as lifetime. Therefore, the development of new SPME fibers is always needed to overcome such limitations.

RESULTS

We presented a novel top-down strategy for in situ construction of vertically oriented hexagonal sulfate intercalated NiCr layered double hydroxide nanosheet arrays (NiCr LDHs-SO4 NSAs) on the Nichrome (NiCr) substrate by hydrothermal treatment in NaOH solution containing (NH4)2S2O8. The results showed that much shorter hydrothermal time was needed for the construction of NiCr@NiCr LDHs-SO4 NSAs fiber in the presence of (NH4)2S2O8. Moreover, the unique NiCr LDHs-SO4 NSAs coating offered open access structure, and thereby more available surface area for adsorption. The resulting fiber exhibited better extraction efficiency for phenolic compounds (PCs), faster mass transfer rate, higher mechanical stability, and longer service life than original NiCr@NiCr LDHs NSs fiber and typical commercially fused-silica fibers. After optimizing conditions, the SPME-HPLC-UV method demonstrated a linear range from 0.05 μg L-1 to 200 μg L-1 with LODs of 0.015-0.156 μg L-1 (S/N = 3) and LOQs of 0.048-0.498 μg L-1 (S/N = 10), as well as good repeatability (3.06%-5.22%) and fiber-to-fiber reproducibility (4.32%-6.49%).

SIGNIFICANCE

The developed SPME-HPLC-UV method with the constructed fiber was applied to the preconcentration and detection of different types of PCs in real water samples, showing satisfactory recoveries ranging from 86.20% to 107.8% with RSDs of 3.18%-6.69%. This study provides a new strategy for in situ construction of bimetallic hydroxides and their derived nanocomposite coatings on the NiCr fiber substrate in practical SPME application.

Mapping the metabolic responses to oxaliplatin-based chemotherapy with in vivo spatiotemporal metabolomics

Adjuvant chemotherapy improves the survival outlook for patients undergoing operations for lung metastases caused by colorectal cancer (CRC). However, a multidisciplinary approach that evaluates several factors related to patient and tumor characteristics is necessary for managing chemotherapy treatment in metastatic CRC patients with lung disease, as such factors dictate the timing and drug regimen, which may affect treatment response and prognosis. In this study, we explore the potential of spatial metabolomics for evaluating metabolic phenotypes and therapy outcomes during the local delivery of the anticancer drug, oxaliplatin, to the lung. 12 male Yorkshire pigs underwent a 3 h left lung in vivo lung perfusion (IVLP) with various doses of oxaliplatin (7.5, 10, 20, 40, and 80 mg/L), which were administered to the perfusion circuit reservoir as a bolus. Biocompatible solid-phase microextraction (SPME) microprobes were combined with global metabolite profiling to obtain spatiotemporal information about the activity of the drug, determine toxic doses that exceed therapeutic efficacy, and conduct a mechanistic exploration of associated lung injury. Mild and subclinical lung injury was observed at 40 mg/L of oxaliplatin, and significant compromise of the hemodynamic lung function was found at 80 mg/L. This result was associated with massive alterations in metabolic patterns of lung tissue and perfusate, resulting in a total of 139 discriminant compounds. Uncontrolled inflammatory response, abnormalities in energy metabolism, and mitochondrial dysfunction next to accelerated kynurenine and aldosterone production were recognized as distinct features of dysregulated metabolipidome. Spatial pharmacometabolomics may be a promising tool for identifying pathological responses to chemotherapy.

Electrodeposited histidine-(CuCr)layered double hydroxides/carbon dots for in-tube solid-phase microextraction of chlorophenols from water, juice, and honey samples followed by HPLC-UV

A novel adsorbent consisting of a composition of carbon dots and CuCr-layered double hydroxides intercalated with l-histidine (C-dots@His/LDHs) was introduced. This adsorbent was electrochemically deposited on the inner surface of a capillary copper tube. It was used as an adsorbent for in-tube solid-phase microextraction of chlorophenols (CPs). Separation and measurement of CPs were done by high-performance liquid chromatography-ultraviolet detector. The main parameters which had the most impact on the extraction efficiency and time such as extraction time and flow rate, desorption time and flow rate, ionic strength (salt concentration) and pH were optimized. Calibration curves (0.5-1000 μg L-1) were plotted in real sample (tap water) under optimal conditions which coefficients of determination better than 0.9893 and relative recoveries in the range of 88-120 % were obtained. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) were obtained in the range of 0.1-1.0 μg L-1 and 0.3-3.0 μg L-1, respectively. The intra- and inter-assay precisions (RSD%, n = 3) were better than 5.9 and 8.8 %, respectively.

Hybrid materials based on deep eutectic solvents for the preconcentration of formaldehyde by SPME in coffee beverages

Coffee is one of the most widely consumed beverages. It can be prepared from green or roasted beans or from instant coffee. Unfortunately, in addition to the aroma obtained in the coffee roasting process, among others, formaldehyde can be produced. In this study, thin-film solid-phase microextraction was used to preconcentrate trace amounts of formaldehyde in different types of coffee with different roasting levels. For this purpose, 18 hybrid materials based on deep eutectic solvents were synthesized and tested as sorbents in thin-film solid-phase microextraction. The coffee samples were brewed, and then formaldehyde present in them was derivatized using the Nash reagent. The sample preparation procedure was optimized for selected DES-based sorbent using a central composite design method and validated. Formaldehyde was determined in almost all samples of second-crack coffee (roasted at 240 °C) at 0.17-0.75 ng mL-1 and in darker-colored instant coffees at 0.18-0.54 ng mL-1.

Molecularly imprinted polymer sheathed mesoporous silica tube as SPME fiber coating for determination of tobacco-specific nitrosamines in water

Tobacco-specific nitrosamines (TSNAs) are probably carcinogenic disinfection byproducts eliciting health risk concerns. The determination and surveillance of TSNAs in water is still cumbersome due to the lack of advanced sample preparation methods. Herein, we prepared a solid phase microextraction (SPME) fiber coated with the molecularly imprinted polymer (MIP) sheathed mesoporous silica tube (MST) composite material, and developed a highly efficient, selective, and sensitive method for the determination of five TSNAs in water. Benefiting from the TSNAs-specific recognition of MIP and the increased specific surface area derived from MST, the MIP@MST fiber exhibited excellent extraction performance for TSNAs, which was much superior to the commercially available SPME fibers. By coupling to high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), the outstanding analytical merits such as low method detection limits (ranging 0.1-6.7 ng L-1) and good reproducibility (intra-fiber and inter-fiber relative standard deviations ranging 4.1 %-11.6 % and 3.5 %-12.2 %, respectively) were achieved with the consumption of 8 mL water sample and 100 μL methanol solvent in 50 min. The feasibility of the SPME-HPLC-MS/MS method was demonstrated in tap water and chloraminated source water, with relative recoveries for the five TSNAs ranging from 85.2 % to 108.5 %. In result, none of the TSNAs were found in the tap water samples, while 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-Butanol (NNAL) were detected in the chloraminated source water samples. The rapid and convenient SPME-HPLC-MS/MS method developed in this study offers a powerful tool for monitoring TSNAs in water.

Exploring the hypolipidemic effects of bergenin from Saxifraga melanocentra Franch: mechanistic insights and potential for hyperlipidemia treatment

OBJECTIVE

The goal of this study was to explore the hypolipidemic effects of bergenin extracted from Saxifraga melanocentra Franch (S. melanocentra), which is a frequently utilized Tibetan medicinal plant known for its diverse bioactivities. Establishing a quality control system for black stem saxifrage is crucial to ensure the rational utilization of its medicinal resources.

METHODS

A one-step polyamide medium-pressure liquid chromatography technique was applied to isolate and prepare bergenin from a methanol extract of S. melanocentra. A zebrafish model of hyperlipidemia was used to investigate the potential hypolipidemic effects of bergenin.

RESULTS

The results revealed that bergenin exhibited substantial hypo efficacy in vivo. Specifically, bergenin significantly reduced the levels of triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c) while simultaneously increasing high-density lipoprotein cholesterol (HDL-c) levels. At the molecular level, bergenin exerted its effects by inhibiting the expression of FASN, SREBF1, HMGCRα, RORα, LDLRα, IL-1β, and TNF while promoting the expression of IL-4 at the transcriptional level. Molecular docking analysis further demonstrated the strong binding affinity of bergenin to proteins such as FASN, SREBF1, HMGCRα, RORα, LDLRα, IL-4, IL-1β, and TNF.

CONCLUSIONS

Findings indicate that bergenin modulates lipid metabolism by regulating lipid and cholesterol synthesis as well as inflammatory responses through signaling pathways associated with FASN, SREBF1, and RORα. These results position bergenin as a potential candidate for the treatment of hyperlipidemia.

The environmental sources of benzophenones: Distribution, pretreatment, analysis and removal techniques

Benzophenones (BPs) have wide practical applications in real human life due to its presence in personal care products, UV-filters, drugs, food packaging bags, etc. It enters the wastewater by daily routine activities such as showering, impacting the whole aquatic system, then posing a threat to human health. Due to this fact, the monitoring and removal of BPs in the environment is quite important. In the past decade, various novel analytical and removal techniques have been developed for the determination of BPs in environmental samples including wastewater, municipal landfill leachate, sewage sludge, and aquatic plants. This review provides a critical summary and comparison of the available cutting-edge pretreatment, determination and removal techniques of BPs in environment. It also focuses on novel materials and techniques in keeping with the concept of "green chemistry", and describes on challenges associated with the analysis of BPs, removal technologies, suggesting future development strategies.

Improving greenness and sustainability of standard analytical methods by microextraction techniques: A critical review

Since environmental awareness has increased in analytical chemistry, the demand for green sample preparation methods continues to grow. Microextractions such as solid-phase microextraction (SPME) and liquid-phase microextraction (LPME) miniaturize the pre-concentration step and are a more sustainable alternative to conventional large-scale extractions. However, the integration of microextractions in standard and routine analysis methods is rare, although these applications are used most frequently and have a role model function. Therefore, it is important to highlight that microextractions are capable to replace large-scale extractions in standard and routine methods. This review discusses the greenness, benefits, and drawbacks of the most common LPME and SPME variants compatible with gas chromatography based on the following key evaluation principles: Automation, solvent consumption, hazards, reusability, energy consumption, time efficiency, and handling. Furthermore, the need to integrate microextractions into standard and routine analytical methods is presented by using method greenness evaluation metrics AGREE, AGREEprep, and GAPI applied to USEPA methods and their replacements.

Polyester fabric-based nano copper-polyhedral oligomeric silsesquioxanes sorbent for thin film extraction of non-steroidal anti-inflammatory drugs

In this study, in-situ preparation of copper nanoparticles under sonoheating conditions followed by coating on commercial polyester fabric is reported. Through the self-assembly interaction of thiol groups and copper nanoparticles, the modified polyhedral oligomeric silsesquioxanes (POSS) was deposited on the fabric's surface. In the next step, radical thiol-ene click reactions were implemented to create more layers of POSSs. Subsequently, the modified fabric was applied for sorptive thin film extraction of non-steroidal anti-inflammatory drugs (NSAIDs) including naproxen, ibuprofen, diclofenac, and mefenamic acid from urine samples, followed by high-performance liquid chromatography equipped with a UV detector. The morphology of the prepared fabric phase was characterized by scanning electron microscopy, water angle contact, energy dispersive spectrometry mapping, analysis of nitrogen adsorption-desorption isotherms, and attenuated total reflectance Fourier transform infrared spectroscopy. The significant extraction parameters, including the acidity of the sample solution, desorption solvent and its volume, extraction time, and desorption time, were investigated using the one-variable-at-a-time approach. Under the optimal condition, NSAIDs' detection limit was 0.3-1 ng mL^-1 with a wide linear range of 1-1000 ng mL^-1. The recovery values were between 94.0% and 110.0%, with relative standard deviations of less than 6.3%. The prepared fabric phase exhibited acceptable repeatability, stability, and sorption property toward NSAIDs in urine samples.

Volatile Composition of Fortification Grape Spirit and Port Wine: Where Do We Stand?

Port wine's prominence worldwide is unequivocal and the grape spirit, which comprises roughly one fifth of the total volume of this fortified wine, is also a contributor to the recognized quality of this beverage. Nonetheless, information about the influence of the grape spirit on the final aroma of Port wine, as well as its volatile composition, is extremely limited. Moreover, the aroma characteristics of Port wines are modulated mainly by their volatile profiles. Hence, this review presents a detailed overview of the volatile composition of the fortification spirit and Port wine, along with the methodologies employed for their characterization. Moreover, it gives a general overview of the Douro Demarcated Region (Portugal) and the relevance of fortification spirit to the production of Port wine. As far as we know, this review contains the most extensive database on the volatile composition of grape spirit and Port wine, corresponding to 23 and 208 compounds, respectively. To conclude, the global outlook and future challenges are addressed, with the position of the analytical coverage of the chemical data on volatile components discussed as crucial for the innovation centered on consumer preferences.

Electropolymerized polypyrrole-MOF composite as a coating material for SPME fiber for extraction VOCs liberated by bacteria

The synthesis of efficient and low-cost coatings for solid-phase microextraction attracted much attention. Conductive polymers are excellent candidates for this purpose due to the possibility of electropolymerization, which results in the reproducible synthesis of films. A plethora of studies reported in the literature concluded that modification of conductive polymers with innovative materials could lead to an increase in sensitivity toward specific analytes. In this work, the metal-organic framework-polypyrrole composite was electrodeposited in one step directly onto a stainless-steel substrate. The effect of synthesis parameters on extraction efficiency was investigated. The obtained PPy@ZIF-8 coating was subjected to physical-chemical characterization using electron microscopy and Fourier-transform IR spectroscopy. The main finding of the study was that the values of the limit of detection and intra- and inter-day reproducibility for analytes with different chemical structures were found to be lower as compared to pure polypyrrole coating. Furthermore, the obtained polypyrrole-MOF coating was applied for the collection of profiles of volatile organic compounds liberated by bacteria. Hence, the polypyrrole@ZIF-8 coating synthesized using a low-cost and facile approach presented in this study can be useful for the profiling of VOCs liberated by bacteria.

Direct Coupling of SPME to Mass Spectrometry

Solid-phase microextraction devices are normally analyzed by gas or liquid chromatography. Their use has become increasingly widespread since their introduction in 1990, and nowadays most analytical laboratories use or have used SPME as an efficient and green method to perform analyte extraction and sample clean-up in one step. The SPME technique is intrinsically flexible, and allows for a high degree of optimization with regard to the extracting phase, as well as the way sample is analyzed. Since its introduction, researchers have been trying different ways to transfer analytes extracted from the solid phase to a mass spectrometer, with the aim to increase throughput and reduce solvent, gas usage and costs associated with conventional chromatographic techniques. Furthermore, but not less important, for pure fun of developing new, more efficient and sensitive analytical strategies! This chapter aims at providing a comprehensive overview of the most relevant non-chromatographic mass spectrometric approaches developed for SPME. Technical aspects of each SPME-MS approach will be discussed, highlighting their advantages, disadvantages and future potential developments. Particular emphasis will be given on the most recent direct coupling approaches using novel ionization approaches, and a concise overview of the existing applications will also be provided.

In-situ growth of covalent organic framework on stainless steel needles as solid-phase microextraction probe coupled with electrospray ionization mass spectrometry for rapid and sensitive determination of tricyclic antidepressants in biosamples

Tricyclic antidepressants (TCAs) including amitriptyline (AT), doxepin (DOX) and nortriptyline (NT) are the first-line drugs for the clinical treatment of depression; however, monitoring TCA concentrations in biological fluids and tissues is necessary to improve therapeutic effect and determine the cause of death in patients. It is of great significance to develop a rapid and sensitive method for real-time monitoring of TCAs in various biosamples. In this work, we fabricated a novel covalent organic framework (COF) based solid-phase microextraction (SPME) probe by an in-situ step-by-step strategy, which was obtained by sequentially modifying 1,3,5-tri (4-aminophenyl) benzene (TPB) and 2, 5-divinylbenzaldehyde (DVA) on the surface of polydopamine layer. The TPB-DVA-COF-SPME probe possessed high specific surface area (1244 m²·g ^- 1), regular pores (3.23 nm), good hydrophobicity and stability, resulting in efficient enrichment for TCAs. Furthermore, the combination of TPB-DVA-COF-SPME probe and ambient electrospray ionization mass spectrometry system (ESI/MS) was firstly proposed for rapid and sensitive determination of TCAs in biosamples. As a result, the developed method exhibited low limits of detection (LODs) (0.1-0.5 μg∙L ^- 1), high enrichment factors (39-218), and low relative standard deviations (RSDs) for one probe (1.2-3.8%) and probe-to-probe (2.0-3.7%). Benefiting from these outstanding performance, TPB-DVA-COF-SPME probe was further successfully applied to biosamples (i.e., serum, liver, kidney, and brain) with excellent reusability, indicating the promising applicability of the TPB-DVA-COF-SPME-ESI/MS as a powerful tool for drug monitoring.

Full Evaporative Vacuum Extraction─A Quantitative and Green Approach for Analysis of Semivolatile Organic Compounds in Drinking Water and Surface Water Using GC-MS

Full evaporative vacuum extraction (FEVE) was developed in this work for analysis of a broad range of semivolatile organic compounds (SVOCs) in drinking water and surface water. Sorbent pens are used in a two-stage process that first evaporates the sample matrix through sorbent beds under vacuum to recover the lighter SVOCs, followed by the application of a higher temperature and stronger vacuum to the sample vial to recover the remaining heavier SVOCs once the matrix has evaporated. After extraction, the sorbent pens are desorbed into a GC-MS using a uniquely designed "splitless" delivery system to maximize sensitivity. Critical extraction and desorption parameters that affect the method performance were optimized. After FEVE, the sorbent pens can be stored for 7-10 days at room temperature while maintaining a less than 15% loss in analyte recovery. As a proof of concept, 10 drinking water and surface water samples were analyzed using this method. 69 analytes were detected in these water samples, with the highest concentration of 1986 ng/L for bromacil. Heptachlor epoxide, chlorpyrifos, metolachlor, butachlor, and 2,3',4',5-tetrachlorobiphenyl were detected in four samples. None of the analytes were above the health and safety thresholds set by California Proposition 65.

Porphyrin-based magnetic porous organic polymer for efficient magnetic solid phase extraction of nonsteroidal anti-inflammatory drugs from water

The ubiquitous occurrence of nonsteroidal anti-inflammatory drugs (NSAIDs) in the environmental water system has drawn significant concerns due to their adverse effects. The accurate monitoring the content of them is of great significance but challenging in terms of the complex matrix and trace concentration. In this work, a porphyrin-based magnetic porous organic polymer composite (PM-POP) was prepared through a solvent-free synthetic method. Owing to the highly porous structure and strong affinities, the as-prepared PM-POP could be utilized as a highly efficient adsorbent for the magnetic solid phase extraction (MSPE) of NSAIDs. Combining with the high-performance liquid chromatography separation with ultraviolet detector (HPLC-UV), a sensitive analytical method was established, which exhibited wide linear ranges (0.1-400 μg/L) and large enrichment factors (EFs) (39.5-82.9 folds) along with good precision (intra-day RSD ≤ 4.9%) and repeatability (inter-day RSD ≤ 8.4%). Ultimately, it was applied to determinate trace NSAIDs in practical water samples successfully, demonstrating its good application prospect in environmental analysis.

A New Trend and Future Perspectives of the Miniaturization of Conventional Extraction Methods for Elemental Analysis in Different Real Samples: A Review

Sample preparation is one of the viable procedures to be used before analysis to enhance sensitivity and reduce the matrix effect. The current review is mainly emphasized the latest outcome and applications of microextraction techniques based on the miniaturization of the classical conventional methods based on liquid-phase and solid-phase extraction for the quantitative elemental analysis in different real samples. The limitation of the conventional sample preparation methods (liquid and solid phase extraction) has been overcome by developing a new way of reducing size as compared with the conventional system through the miniaturization approach. Miniaturization of the sample preparation techniques has received extensive attention due to its extraction at microlevels, speedy, economical, eco-friendly, and high extraction capability. The growing demand for speedy, economically feasible, and environmentally sound analytical approaches is the main intention to upgrade the conventional procedures apply for sample preparation in environmental investigation. A growing trend of research has been perceived to quantify the trace for elemental analysis in different natures of real samples. This review also recapitulates the current futuristic scenarios for the green and economically viable procedure with special overemphasis and concentrates on eco-friendly miniaturized sample-preparation techniques such as liquid-phase microextraction (LPME) and solid-phase microextraction (SPME). This review also emphasizes the latest progress and applications of the LPME and SPME approach and their future perspective.

Recent applications of organic molecule-based framework porous materials in solid-phase microextraction for pharmaceutical analysis

Sample preparation is an indispensable part of detection of complex samples in pharmaceutical analysis. Solid-phase microextraction (SPME) has obtained a lot of attention due to its advantages of time saving, less solvent and easily automation. A variety of functional materials are used as sorbents in SPME to carry out selective and high extraction. This review centers around the recent applications of organic molecule-based framework porous materials, such as metal organic frameworks (MOFs) and covalent organic frameworks (COFs), as SPME coating materials mainly focus on pharmaceutical analysis in food, environment, and biological samples. Four representative extraction devices are introduced, including on-fiber SPME, in-tube SPME, thin film SPME, stir bar SPME. The application prospect of other organic porous materials as sorbents for pharmaceutical analysis are also discussed, such as hyper crosslinked polymers (HCPs) and conjugated microporous polymers (CMPs). The progresses and discusses are provided to offer references for further research focusing on application and development of organic molecule-based framework porous materials in the field of SPME.

The metabolic fate of oxaliplatin in the biological milieu investigated during in vivo lung perfusion using a unique miniaturized sampling approach based on solid-phase microextraction coupled with liquid chromatography-mass spectrometry

Adjuvant chemotherapy after pulmonary metastasectomy for colorectal cancer may reduce recurrence and improve survival rates; however, the benefits of this treatment are limited by the significant side effects that accompany it. The development of a novel in vivo lung perfusion (IVLP) platform would permit the localized delivery of high doses of chemotherapeutic drugs to target residual micrometastatic disease. Nonetheless, it is critical to continuously monitor the levels of such drugs during IVLP administration, as lung injury can occur if tissue concentrations are not maintained within the therapeutic window. This paper presents a simple chemical-biopsy approach based on sampling with a small nitinol wire coated with a sorbent of biocompatible morphology and evaluates its applicability for the near-real-time in vivo determination of oxaliplatin (OxPt) in a 72-h porcine IVLP survival model. To this end, the pigs underwent a 3-h left lung IVLP with 3 doses of the tested drug (5, 7.5, and 40 mg/L), which were administered to the perfusion circuit reservoir as a bolus after a full perfusion flow had been established. Along with OxPt levels, the biocompatible solid-phase microextraction (SPME) probes were employed to profile other low-molecular-weight compounds to provide spatial and temporal information about the toxicity of chemotherapy or lung injury. The resultant measurements revealed a rather heterogeneous distribution of OxPt (over the course of IVLP) in the two sampled sections of the lung. In most cases, the OxPt concentration in the lung tissue peaked during the second hour of IVLP, with this trend being more evident in the upper section. In turn, OxPt in supernatant samples represented ∼25% of the entire drug after the first hour of perfusion, which may be attributable to the binding of OxPt to albumin, its sequestration into erythrocytes, or its rapid nonenzymatic biotransformation. Additionally, the Bio-SPME probes also facilitated the extraction of various endogenous molecules for the purpose of screening biochemical pathways affected during IVLP (i.e., lipid and amino acid metabolism, steroidogenesis, or purine metabolism). Overall, the results of this study demonstrate that the minimally invasive SPME-based sampling approach presented in this work can serve as (pre)clinical and precise bedside medical tool.

Mussel Inspired Polydopamine as Silica Fibers Coating for Solid-Phase Microextraction

Commercial solid-phase microextraction fibers are available in a limited number of expensive coatings, which often contain environmentally harmful substances. Consequently, several different approaches have been used in the attempt to develop new sorbents that should possess intrinsic characteristics such as duration, selectivity, stability, and eco-friendliness. Herein we reported a straightforward, green, and easy coating method of silica fibers for solid-phase microextraction with polydopamine (PDA), an adhesive, biocompatible organic polymer that is easily produced by oxidative polymerization of dopamine in mild basic aqueous conditions. After FT-ATR and SEM characterization, the PDA fibers were tested via chromatographic analyses performed on UHPLC system using biphenyl and benzo(a)pyrene as model compounds, and their performances were compared with those of some commercial fibers. The new PDA fiber was finally used for the determination of selected PAHs in soot samples and the results compared with those obtained using the commercial PA fiber. Good reproducibility, extraction stability, and linearity were obtained using the PDA coating, which proved to be a very promising new material for SPME.

Vanillin-crosslinked chitosan/ZnO nanocomposites as a drug delivery system for 5-fluorouracil: study on the release behavior via mesoporous ZrO2-Co3O4 nanoparticles modified sensor and antitumor activity

Herein, a series of vanillin-crosslinked chitosan (Vn-CS) nanocomposites (NCs) containing various contents of ZnO nanoparticles (NPs) was prepared and characterized via FTIR spectroscopy, XRD, TGA, SEM and TEM. Changing the weight% of ZnO NPs in the prepared NCs resulted in an improvement in their antibacterial activity against Gram-negative and Gram-positive bacteria strains compared with the unmodified CS, and the encapsulation efficiency of 5-fluorouracil (5-FU) was found to be in the range of 61.4–69.2%. Subsequently, the release of 5-FU was monitored utilizing the mesoporous ZrO₂–Co₃O₄ NPs modified carbon paste sensor via the square-wave adsorptive anodic stripping voltammetry (SW-AdASV) technique. Also, the release mechanism of 5-FU from each NC was studied by applying the zero-order, first-order, Hixson–Crowell and Higuchi models to the experimental results. The cytotoxicity of prepared NCs and 5-FU-encapsulated NCs was evaluated against the HePG-2, MCF-7 and HCT-116 cancer cell lines, in addition to the WI-38 and WISH normal cell lines using the MTT assay. Notably, 5-FU/CV₁₀ NC exhibited the highest antitumor activity towards all tested cancer cell lines and a moderate activity against WI-38 and WISH normal cell lines with IC₅₀ values of 28.02 ± 2.5 and 31.65 ± 2.7 μg mL⁻¹, respectively. The obtained nanocomposites exhibited suitable selectivity with minimum toxicity against normal cells.

Herein, a series of vanillin-crosslinked chitosan (Vn-CS) nanocomposites (NCs) containing various contents of ZnO nanoparticles (NPs) was prepared and characterized via FTIR spectroscopy, XRD, TGA, SEM and TEM.

Swellable Sorbent Coatings for Parallel Extraction, Storage, and Analysis of Plant Metabolites

Quantitative and qualitative measurements of trace-level analytes in plants or foodstuffs, e.g., secondary metabolites like carotenoids, are often performed at centralized core facilities or off-site laboratories. However, preparation, storage, and/or transport of both intact samples and sample extracts may be cumbersome and complicated, especially for air-sensitive analytes. We describe the development of inexpensive swellable microextraction (SweME) devices for extraction and storage of nonpolar analytes. SweME devices consist of a thin layer of poly(dimethylsiloxane) (PDMS) grafted onto a stainless steel support. Pretreating the SweME device with small volumes of the organic solvent causes the PDMS to swell. The swollen SweME device can then be immersed directly into complex matrices for absorptive extraction of low-molecular-weight, nonpolar analytes. Following storage, analytes can be solvent-desorbed prior to characterization. Proof-of-principle work with carotenoids from tomatoes and carrots demonstrates that SweME is appropriate for semiquantitative analyses and increases the stability of air-sensitive analytes during storage at ambient temperatures as compared to the solvent extracts. Carotenoid profiles (fractional carotenoid contributions) from tomato and carrot samples were well correlated between SweME and liquid-liquid extraction (R² = 0.97 and 0.94). Lycopene, the most abundant carotenoid in tomatoes, saw a less than 20% decrease in extracted mass during 1 month of ambient SweME storage. Extractions and desorptions can be run in parallel using multiwell plates. In summary, swelled sorbent extraction with SweME devices is a convenient and inexpensive approach for isolation and storage of analytes in complex matrices and may be particularly well suited for evaluating large numbers of plant samples through external laboratories.

Deep Eutectic Solvent-Based Coating Sorbent for Preconcentration of Formaldehyde by Thin-Film Solid-Phase Microextraction Technique

A thin-film solid-phase microextraction method with a sorbent composed of a deep eutectic solvent was developed for the preconcentration of formaldehyde from river and lake water samples. Four new deep eutectic solvents (DESs) were synthesized, each in molar ratios 1:1, 1:2, and 1:3. Among prepared compounds, the greatest efficiency in the proposed method of preconcentration of formaldehyde derivatized with Nash reagent was demonstrated by DES-3 consisting of benzyldimethylhexadecylammonium chloride and lauric acid, in a molar ratio of 1:3. For the proposed method, the parameters affecting the extraction efficiency of formaldehyde were optimized (including the choice of DES-based sorbent and desorption solvent as well as the sample volume and pH, the salting-out effect, the extraction time, and the desorption time). Under optimal conditions, the proposed method achieved good precision between 3.3% (for single sorbent) and 4.8% (for sorbent-to-sorbent) as well as good recovery ranging from 78.0 to 99.1%. The limits of detection and quantitation were 0.15 ng mL−1 and 0.50 ng mL−1, respectively. The enrichment factor was equal to 178. The developed method was successfully applied to determine formaldehyde in environmental water samples.

Sequential thin film-solid phase microextraction as a new strategy for addressing displacement and saturation effects in food analysis

Solid-phase microextraction (SPME) is robust, selective, sensitive, and can be automated. However, low extraction phase to sample volume ratio sometimes results in saturation, competition, or swelling phenomena in complex samples. A sequential extraction method using two thin-film SPME (TF-SPME) devices with different selectivities was developed. The sequential application of the thin films provided higher extraction capacities, while avoiding swelling, saturation, and displacement effects, and enabled the quantitative determination of all compounds in the analyzed samples, independent of their polarity and affinity to extraction phases. In the first step, a TF-SPME device with a poly(dimethylsiloxane) (PDMS) coating was used to deplete non-polar and other compounds present at high concentrations in the sample, which are typically associated with the undesirable phenomena. In the second step, a TF-SPME device coated with a combination of hydrophobic/lipophilic balanced (HLB) particles and PDMS (HLB/PDMS) was applied for the direct microextraction of the remaining compounds, including polar compounds left over after the first step. The proposed method resulted in decreased levels of interference and yielded encouraging analytical data for beer samples.

Aroma Clouds of Foods: A Step Forward to Unveil Food Aroma Complexity Using GC × GC

The human senses shape the life in several aspects, namely well-being, socialization, health status, and diet, among others. However, only recently, the understanding of this highly sophisticated sensory neuronal pathway has gained new advances. Also, it is known that each olfactory receptor cell expresses only one type of odorant receptor, and each receptor can detect a limited number of odorant substances. Odorant substances are typically volatile or semi-volatile in nature, exhibit low relative molecular weight, and represent a wide variety of chemical families. These molecules may be released from foods, constituting clouds surrounding them, and are responsible for their aroma properties. A single natural aroma may contain a huge number of volatile components, and some of them are present in trace amounts, which make their study especially difficult. Understanding the components of food aromas has become more important than ever with the transformation of food systems and the increased innovation in the food industry. Two-dimensional gas chromatography and time-of-flight mass spectrometry (GC × GC-ToFMS) seems to be a powerful technique for the analytical coverage of the food aromas. Thus, the main purpose of this review is to critically discuss the potential of the GC × GC–based methodologies, combined with a headspace solvent-free microextraction technique, in tandem with data processing and data analysis, as a useful tool to the analysis of the chemical aroma clouds of foods. Due to the broad and complex nature of the aroma chemistry subject, some concepts and challenges related to the characterization of volatile molecules and the perception of aromas will be presented in advance. All topics covered in this review will be elucidated, as much as possible, with examples reported in recent publications, to make the interpretation of the fascinating world of food aroma chemistry more attractive and perceptive.

Matrix compatibility of typical sol-gel solid-phase microextraction coatings in undiluted plasma and whole blood for the analysis of phthalic acid esters

Sol-gel materials have been widely used for solid-phase microextraction (SPME) coatings due to their outstanding performance; in contrast, sol-gel SPME coatings have seldom been used for in vivo sampling. The main reason is that their matrix compatibility is unclear. In order to promote the application of this type of coating and accelerate the development of in vivo SPME, in this study, the matrix compatibility of several typical sol-gel coatings was assessed in plasma and whole blood using phthalic acid esters as analytes. The service life of five kinds of sol-gel coatings was among 20-35 times in undiluted plasma, while it was 27 times for a homemade commercial polydimethylsiloxane coating, which indicates good matrix compatibility of sol-gel coatings in untreated plasma. The sol-gel hydroxy-terminated silicone oil/methacrylic acid fiber achieved the highest extraction ability among all of the fibers, and it was tested in pig whole blood. It could be continuously used for at least 22 times, demonstrating good potential for in vivo sampling. Subsequently, a direct-immersion SPME/gas chromatography-flame ionization detection method was established for the determination of 5 phthalic acid esters in blood. Compared with other methods reported in the literature, this method is rapid, simple, sensitive, and accurate, and does not need expensive instruments or tedious procedures. A simulation system of animal blood circulation was constructed to verify the practicability of sol-gel SPME coatings in animal vein sampling. The result illustrated the feasibility of that coating for in vivo blood sampling, but a more accurate quantification calibration approach needs to be explored.

Determination of Nitrofuran Metabolites in Complex Food Matrices Using a Rough, Cheap, Easy-Made Wooden-Tip-Based Solid-Phase Microextraction Probe and LC-MS/MS

In this study, a rough, cheap, easy-made wooden-tip-based solid-phase microextraction (SPME) probe was first developed for simultaneous determination of 4 nitrofuran metabolite derivatives in complex food matrices via LC-MS/MS. A simple dip-coating method was used to coat wooden tips with biocompatible polyacrylonitrile (PAN) and N-vinylpyrrolidone-co-divinylbenzene, also known as HLB particles, which served as the extractive substrate in the proposed device. Compared with the traditional solid-phase extraction (SPE) method, the proposed device shortens sample clean-up time, reduces solvent consumption, and decreases testing costs. In addition, the main parameters affecting the SPME procedure efficiency were investigated in detail and the optimal conditions were found. The method was validated using three different food matrixes (pork, croaker, and honey) by spiking with the four metabolites at 0.5, 1.0, and 5.0 μg/kg, as well as their internal standards. The average recovery of all nitrofuran metabolite derivatives ranges from 97.4–109.5% (pork), 87.5–112.7% (croaker), and 98.6–109.0% (honey). Relative standard deviations were all <10% for intraday and interday precision. The values of limit of detection and limit of quantification were, respectively, ranging from 0.011 to 0.123 and 0.033 to 0.369 μg/kg (pork), 0.009 to 0.112 and 0.027 to 0.339 μg/kg (croaker), and 0.010 to 0.131 and 0.030 to 0.293 μg/kg (honey). The presented method was applied to the analysis of real positive samples.

Development of novel thin-film solid-phase microextraction materials based on deep eutectic solvents for preconcentration of trace amounts of parabens in surface waters

A green and sensitive thin-film solid-phase microextraction method based on deep eutectic solvent was developed that enables simultaneous isolation, preconcentration, and determination of parabens in surface waters. Six new deep eutectic solvents were synthesized and used directly to prepare thin-film coatings on a stainless steel mesh support. Among the compounds obtained, the highest efficiency in the extraction of parabens was found for a material consisting of trihexyltetradecylphosphonium chloride and n-docosanol in a molar ratio of 1:2. For the proposed method, parameters affecting the extraction efficiency of parabens, such as the coating material, the desorption solvent, the volume of the sample, the pH of the sample, the extraction and desorption time, and the salting-out effect, were optimized. Under optimal conditions, the proposed method allowed us to achieve good precision between 3.6 and 6.5% and recovery ranging from 68.1 to 91.4%. The limits of detection range from 0.018 to 0.055 ng mL^-1 . This article is protected by copyright. All rights reserved.

Advanced Solid-Phase Microextraction Techniques and Related Automation: A Review of Commercially Available Technologies

The solid-phase microextraction (SPME), invented by Pawliszyn in 1989, today has a renewed and growing use and interest in the scientific community with fourteen techniques currently available on the market. The miniaturization of traditional sample preparation devices fulfills the new request of an environmental friendly analytical chemistry. The recent upswing of these solid-phase microextraction technologies has brought new availability and range of robotic automation. The microextraction solutions propose today on the market can cover a wide variety of analytical fields and applications. This review reports on the state-of-the-art innovative solid-phase microextraction techniques, especially those used for chromatographic separation and mass-spectrometric detection, given the recent improvements in availability and range of automation techniques. The progressively implemented solid-phase microextraction techniques and related automated commercially available devices are classified and described to offer a valuable tool to summarize their potential combinations to face all the laboratories requirements in terms of analytical applications, robustness, sensitivity, and throughput.

Polyamide Noncoated Device for Adsorption-Based Microextraction and Novel 3D Printed Thin-Film Microextraction Supports

Polyamide noncoated device for adsorption-based microextraction (PANDA microextraction) is a brand new, easy to prepare, environmentally friendly, inexpensive, and efficient sample preparation method created entirely with the use of 3D printing. The proposed method is based on the extractive proprieties of the unmodified polyamide and carbon fiber blends and is compared with the highly selective thin-film microextraction (TFME). In addition, 3D printing was used to simplify the process of TFME. Prototype sample preparation devices were evaluated by the extraction of oral fluid spiked with 38 small molecules with diverse chemical natures, such as lipophilicity in the log P range of 0.2–7.2. The samples were analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry. The results indicate that chemically and thermally resistant 3D printed supports can be successfully used as a cost-saving, environmentally friendly solution for the preparation of TFME devices, alternative to the conventional metal supports, with only marginal differences in the extraction yield (mean = 4.0%, median = 1.8%, range = 0.0–22.3%, n = 38). Even more remarkably, in some cases, the newly proposed PANDA microextraction method exceeded the reference TFME in terms of the extraction efficacy and offered excellent sample cleanup as favorable matrix effects were observed (mean = −8.5%, median = 7.5%, range = −34.7–20.0%, n = 20). This innovative approach paves the road to the simplified sample preparation with the use of emerging extractive 3D printing polymers.