Innovative extraction materials for fiber-in-tube solid phase microextraction: A review

Eco-friendly high-throughput screening of cephalosporins impurities: Utilizing 2D-carbon microfiber fractionation system combined with quadrupole time of flight high-resolution mass spectrometer

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Internal multiple interactions-adsorption and external zwitterionic polymer-exclusion of restricted access materials as adsorbent for offline and online extraction of neonicotinoid pesticides in Goji samples

A method based on novel restricted access materials (RAMs) for the determination of neonicotinoid pesticides in Goji samples using offline and online solid phase extraction (SPE) coupled with high-performance liquid chromatography (LC). RAMs were synthesized using poly(chloromethylstyrene-co-divinylbenzene) (PVBC/DVB) microspheres as substrate, styrene (St) and n-vinylpyrrolidone (NVP) were first copolymerized on the interior to construct adsorption sites, and sulfobetaine methacrylate (SBMA) was then polymerized on the exterior to form exclusion sites via two-step surface initiated-atom transfer polymerization. The prepared PVBC/DVB@poly(St-co-NVP)@poly(SBMA) RAMs could efficiently extract neonicotinoid pesticides and automatically exclude proteins. Under the optimized conditions, the developed methods of offline (magnetic SPE and SPE column) and online extraction coupled with LC both using PVBC/DVB@poly(St-co-NVP)@poly(SBMA) RAMs as the extractant, exhibit a wide linearity, low limits of detection and limit of quantification and good inter-day and intra-day precision with satisfactory recoveries. Among these methods, online extraction coupled with LC based on novel RAMs exhibits clear advantages for the determination of neonicotinoid pesticides in Goji samples has clear advantages, such as simple operation by direct injection, short extraction times, and high accuracy with less human error.

A functionalized glass fiber as the adsorbent for efficient analysis of endocrine disruptors in aqueous environments

Estrogens and bisphenols are typical endocrine disruptors (EDs) that pose a potential hazard to the human body due to their widespread presence in aqueous environments. In this study, a β-cyclodextrin porous crosslinked polymer (β-CD-PCP) was prepared in-situ on a glass fiber surface by a nucleophilic substitution reaction. An effective and sensitive solid phase microextraction method using functionalized glass fiber with β-CD-PCP coating as the adsorbent was established for the detection of 11 EDs in a water environment. The β-CD-PCP was in-situ prepared on a glass fiber surface by a nucleophilic substitution reaction. The β-CD-PCP successfully separated five estrogens (ESTs) and six bisphenols (BPs) through hydrophobic and π-π interactions. The conditions affecting extraction were optimized. Under the optimized conditions, the ESTs obtained a high enrichment effect (1795-2328), low limits of detection (0.047 µg L-1) and a good linearity range (0.2-15.0 µg L-1). Furthermore, the spiked recoveries of analyte ESTs in aqueous environments were between 82.9-115.7 %. The results indicated that the prepared functionalized glass fibers exhibited good adsorption properties, and the established analytical method was reliable for monitoring trace ESTs and BPs in aqueous environments.

Recent progress of covalent organic frameworks as attractive materials for solid-phase microextraction: A review

Solid-phase microextraction (SPME) is a green, environmentally friendly, and efficient technique for sample pre-treatment. Covalent organic frameworks (COFs), a class of porous materials formed by covalent bonds, have gained prominence owing to their remarkable attributes, including large specific surface area, tunable pore size, and robust thermal/chemical stability. These characteristics have made COFs highly appealing as potential coatings for SPME fiber over the past decades. In this review, various methods used to prepare SPME coatings based on COFs are presented. These methods encompass physical adhesion, sol-gel processes, in situ growth, and chemical cross-linking strategies. In addition, the applications of COF-based SPME coating fibers for the preconcentration of various targets in environmental, food, and biological samples are summarized. Moreover, not only their advantages but also the challenges they pose in practical applications are highlighted. By shedding light on these aspects, this review aims to contribute to the continued development and utilization of COF materials in the field of sample pretreatment.

Molecularly imprinted polymers in online extraction liquid chromatography methods: Current advances and recent applications

BACKGROUND

One of the primary objectives in green analytical practices is the seamless integration of extraction and separation steps, resulting in the augmentation of both analytical throughput and method performance. Consequently, the exploration of prospective sorbent materials has drawn significant attention in the scientific community, particularly concerning the potential for online procedures. Employing the optimal sorbent material within an automated analytical approach holds the promise of elevating the precision of the analytical evaluation. Molecularly imprinted polymers (MIPs) excel in specific analyte interaction within complex matrices. However, MIPs' full potential was not widely exploring especially for online analytical methodologies.

RESULTS

Here is presented a comprehensive overview of the current applications of MIPs as sorbent materials within integrated and automated separation methodologies applied to diverse matrices including biological, food, and environmental samples. Notably, their primary advantage, as evidenced in the literature, lies in their exceptional selectivity for the target analyte discussed according to the adopted synthesis protocol. Furthermore, the literature discussed here illustrates the versatility of MIPs in terms of modification with one or more phases which are so-called hybrid materials, such as molecularly imprinted monoliths (MIM), the molecularly imprinted ionic liquid polymer (IL-MIP), and restricted access to molecularly imprinted polymer (RAMIP). The reported advantages enhance their applicability in integrated and automated separation procedures, especially to the column switching methods, across a broader spectrum of applications.

SIGNIFICANCE

This revision aims to demonstrate the MIP's potential as a sorbent phase in integrated and automated methods, this comprehensive overview of MIP polymers in integrated and automated separation methodologies can be used as a valuable guide, inspiring new research on developing novel horizons for MIP applications to have their potential emphasized in analytical science and enhanced to the great analytical methods achievement.

Modified stainless steel wires with superwettability for highly efficient in-tube solid-phase microextraction

Construction of different surface wettability is meaningful for the interaction between the sorbent surface and target components. In the current study, four kinds of stainless-steel wires (SSWs) with different hydrophobic/hydrophilic property were prepared and used as the absorbents to enrich the target compounds with different polarity. Comparative extraction of six non-polar polycyclic aromatic hydrocarbons (PAHs) and six polar estrogens was carried out by in-tube solid phase microextraction (IT-SPME). The results showed that two SSWs with the superhydrophobic surfaces exhibited high extraction capacity to the non-polar PAHs with the superior enrichment factor (EF) in the range of 29-672 and 57-744, respectively. In contrast, the superhydrophilic SSWs demonstrated higher enrichment efficiency for the polar estrogens than other hydrophobic SSWs. On the basis of optimized conditions, a validated analysis method was established using six PAHs as model analytes for IT-SPME-HPLC. Acceptable linear ranges (0.5-10 μg L^-1) and low detection limits (0.0056-0.32 μg L^-1) were achieved using the superhydrophobic wire modified by perfluorooctyl trichlorosilane (FOTS). The relative recoveries spiked at 2, 5 and 10 μg L^-1 in the lake water samples were in the range of 81.5%-113.7%. The relative standard deviation (RSD) of intraday (≤0.8%, n = 3) and interday (≤5.3%, n = 3) tests demonstrated the good extraction repeatability for the same extraction tube. Satisfactory repeatability for the preparation of extraction tubes (n = 3) was also obtained with the RSD values in the range of 3.6%-8.0%.

Advances in sample preparation and HPLC-MS/MS methods for determining amyloid-β peptide in biological samples: a review

Alzheimer's disease (AD), a neurological disorder, is a major public health concern and the most common form of dementia. Its typical symptoms include memory loss, confusion, changes in personality, and cognitive impairment, which result in patients gradually losing independence. Over the last decades, some studies have focused on searching for effective biomarkers as early diagnostic indicators of AD. Amyloid-β (Aβ) peptides have been consolidated as reliable AD biomarkers and have been incorporated into modern diagnostic research criteria. However, quantitative analysis of Aβ peptides in biological samples remains a challenge because both the sample and the physical-chemical properties of these peptides are complex. During clinical routine, Aβ peptides are measured in the cerebrospinal fluid by immunoassays, but the availability of a specific antibody is critical-in some cases, an antibody may not exist, or its specificity may be inadequate, leading to low sensitivity and false results. HPLC-MS/MS has been reported as a sensitive and selective method for determining different fragments of Aβ peptides in biological samples simultaneously. Developments in sample preparation techniques (preconcentration platforms) such as immunoprecipitation, 96-well plate SPME, online SPME, and fiber-in-tube SPME have enabled not only effective enrichment of Aβ peptides present at trace levels in biological samples, but also efficient exclusion of interferents from the sample matrix (sample cleanup). This high extraction efficiency has provided MS platforms with higher sensitivity. Recently, methods affording LLOQ values as low as 5 pg mL^-1 have been reported. Such low LLOQ values are adequate for quantifying Aβ peptides in complex matrixes including cerebrospinal fluid (CSF) and plasma samples. This review summarizes the advances in mass spectrometry (MS)-based methods for quantifying Aβ peptides and covers the period 1992-2022. Important considerations regarding the development of the HPLC-MS/MS method such as the sample preparation step, optimization of the HPLC-MS/MS parameters, and matrix effects are described. Clinical applications, difficulties related to analysis of plasma samples, and future trends of these MS/MS-based methods are also discussed.

N, N'-methylene bisacrylamide/divinyl benzene based-highly cross-linked hybrid monolithic column: Production and its applications for powerful capture of four chlorophenols

In this paper, the role of the halogen bond in capillary monolithic column microextraction was explored for the first time. Benzene-1,3,5-tricarbohydrazide (BTH) was synthesized as a functional monomer, N, N'-methylene bisacrylamide (MBA) and divinyl benzene (DVB) were used as cross-linking agents, the hybrid monolithic column of poly (BTH-co-DVB-co-MBA) was prepared using methanol and polyethylene glycol as pore-forming agents and azodiisobutyronitrile as the initiator. Due to the existence of BTH, a large number of nitrogen atoms (Lewis base) were introduced into the monolithic column, which could form a halogen bond with chlorine-containing organic pollutants and enhance its adsorption performance. Based on the monolithic column, a sensitive and environment-friendly solid-phase microextraction technology was studied. The monolithic column was integrated with high-performance liquid chromatography (HPLC) to extract and detect four kinds of chlorophenol in real water samples. Under best conditions, the method showed excellent extraction ability and linearity, with a linear correlation coefficient of 0.9958-0.9987, a low detection limit (LOD) of 0.04-0.23 μg L^-1 (S/N = 3), and relative standard deviation (RSD) less than 3.09%. The recovery rate was kept between 87.30% and 123.00%, and the RSD was less than 3.83%, which indicated that the column had powerful capture performance, high precision, and strong anti-matrix interference ability in the real sample, and had potential application value in practical work.

Current Developments of Analytical Methodologies for Aflatoxins' Determination in Food during the Last Decade (2013-2022), with a Particular Focus on Nuts and Nut Products

This review aims to provide a clear overview of the most important analytical development in aflatoxins analysis during the last decade (2013-2022) with a particular focus on nuts and nuts-related products. Aflatoxins (AFs), a group of mycotoxins produced mainly by certain strains of the genus Aspergillus fungi, are known to impose a serious threat to human health. Indeed, AFs are considered carcinogenic to humans, group 1, by the International Agency for Research on Cancer (IARC). Since these toxins can be found in different food commodities, food control organizations worldwide impose maximum levels of AFs for commodities affected by this threat. Thus, they represent a cumbersome issue in terms of quality control, analytical result reliability, and economical losses. It is, therefore, mandatory for food industries to perform analysis on potentially contaminated commodities before the trade. A full perspective of the whole analytical workflow, considering each crucial step during AFs investigation, namely sampling, sample preparation, separation, and detection, will be presented to the reader, focusing on the main challenges related to the topic. A discussion will be primarily held regarding sample preparation methodologies such as partitioning, solid phase extraction (SPE), and immunoaffinity (IA) related methods. This will be followed by an overview of the leading analytical techniques for the detection of aflatoxins, in particular liquid chromatography (LC) coupled to a fluorescence detector (FLD) and/or mass spectrometry (MS). Moreover, the focus on the analytical procedure will not be specific only to traditional methodologies, such as LC, but also to new direct approaches based on imaging and the ability to detect AFs, reducing the need for sample preparation and separative techniques.

In-Tube Solid-Phase Microextraction Directly Coupled to Mass Spectrometric Systems: A Review

Since it was introduced in 1997, in-tube solid-phase microextraction (in-tube SPME), which uses a capillary column as extraction device, has been continuously developed as online microextraction coupled to LC systems (in-tube SPME-LC). In the last decade, new couplings have been evaluated on the basis of state-of-the-art LC instruments, including direct coupling of in-tube SPME to MS/MS systems, without chromatographic separation, for high-throughput analysis. In-tube SPME coupling to MS/MS has been possible thanks to the selectivity of capillary column coatings and MS/MS systems (SRM mode). Different types of capillary columns (wall-coated open-tubular, porous-layer open-tubular, sorbent-packed, porous monolithic rods, or fiber-packed) with selective stationary phases have been developed to increase the sorption capacity and selectivity of in-tube SPME. This review focuses on the in-tube SPME principle, extraction configurations, current advances in direct coupling to MS/MS systems, experimental parameters, coatings, and applications in different areas (food, biological, clinical, and environmental areas) over the last years.

A review of the modern principles and applications of solid-phase extraction techniques in chromatographic analysis

Analytical processes involving sample preparation, separation, and quantifying analytes in complex mixtures are indispensable in modern-day analysis. Each step is crucial to enriching correct and informative results. Therefore, sample preparation is the critical factor that determines both the accuracy and the time consumption of a sample analysis process. Recently, several promising sample preparation approaches have been made available with environmentally friendly technologies with high performance. As a result of its many advantages, solid-phase extraction (SPE) is practiced in many different fields in addition to the traditional methods. The SPE is an alternative method to liquid–liquid extraction (LLE), which eliminates several disadvantages, including many organic solvents, a lengthy operation time and numerous steps, potential sources of error, and high costs. SPE advanced sorbent technology reorients with various functions depending on the structure of extraction sorbents, including reversed-phase, normal-phase, cation exchange, anion exchange, and mixed-mode. In addition, the commercial SPE systems are disposable. Still, with the continual developments, the restricted access materials (RAM) and molecular imprinted polymers (MIP) are fabricated to be active reusable extraction cartridges. This review will discuss all the theoretical and practical principles of the SPE techniques, focusing on packing materials, different forms, and performing factors in recent and future advances. The information about novel methodological and instrumental solutions in relation to different variants of SPE techniques, solid-phase microextraction (SPME), in-tube solid-phase microextraction (IT-SPME), and magnetic solid-phase extraction (MSPE) is presented. The integration of SPE with analytical chromatographic techniques such as LC and GC is also indicated. Furthermore, the applications of these techniques are discussed in detail along with their advantages in analyzing pharmaceuticals, biological samples, natural compounds, pesticides, and environmental pollutants, as well as foods and beverages.

The DI-SPME Method for Determination of Selected Narcotics and Their Metabolites, and Application to Bone Marrow and Whole Blood Analysis

The present investigation utilised the quick and easy SPME/LC-MS method to determine selected narcotic substances and their metabolites in whole blood. The study included qualitative analysis and validation of the method. Analytes were determined in the linearity range of 25−300 ng/mL. The precision during and between days (in general CV < 13.41%), and the LOD which results in between 0.36 and 11.08 ng/mL, and the LOQ between 1.20 and 36.90 ng/mL were investigated. The validation results obtained, as well as the results of subsequent in-laboratory tests, confirmed the applicability of the method in the analysis of blood samples. An attempt to apply the method to the analysis of bone marrow samples has yielded promising results; however, more detailed studies are needed in this area.

Silica Aerogel Hybridized with Melamine-Terephthalaldehyde Polymer for In-Tube Solid-Phase Microextraction of Polycyclic Aromatic Hydrocarbons from Environment Water

To improve the extraction performance of the silica aerogel, a melamine-terephthalaldehyde polymer was used to hybridize silica aerogel, and the hybridized aerogel was coated on the surface of stainless steel wire to prepare a fiber-filled extraction tube through placing four wires into a polyetheretherketone tube. The tube was combined with high-performance liquid chromatography, then the online extraction and detection were established. Several polycyclic aromatic hydrocarbons (PAHs) were selected as the target analytes. Under the optimum extraction and desorption conditions, the limit of detection was as low as 3.0 ng L⁻¹, and the linear range was 0.01–20.0 μg L⁻¹. The enrichment factors of PAHs were in the range of 1724–2393. Three environmental water samples of mineral water, tap water and river water were analyzed by this method, and the recoveries that spiked at 1.0–10.0 μg L⁻¹ were between 80.5–126%. It showed many advantages compared with other methods, such as better sensitivity, faster detection and online analysis.

Fabrication of functional group-rich monoliths for magnetic field-assisted in-tube solid phase microextraction of inorganic selenium species in water samples followed by online chromatographic determination

Efficient separation and enrichment is a crucial step in the analysis of Se(IV) and Se(VI). In the present study, for the first time, online monolith-based magnetic field-assisted in-tube solid phase microextraction (MFA/IT-SPME) was applied to capture inorganic selenium species in water samples. To this aim, porous monoliths mixed with magnetic nanoparticles were synthesized in a silica capillary and employed as a microextraction column (MEC) for MFA/IT-SPME. After that, a magnetic coil utilized to induce variable magnetic fields in adsorption and desorption steps was entwined around the MEC. Se(IV) was coordinated with o-phenylenediamine to form a coordination compound that was infused onto the MEC to be captured. Results evidenced that application of magnetic field during the extraction procedure assisted the capture of the Se(IV)-OPA complex, with an enhancement in the extraction efficiency from 83% to 97%. Under the optimized conditions, MFA/IT-SPME was online combined with HPLC equipped with a diode array detector (DAD) to perform quantification of Se(IV) and Se(VI) in environmental water samples. Total inorganic Se was quantified after pre-reduction of Se(VI) to Se(IV) prior to applying the established approach, and a subtraction method was adopted to calculate the Se(VI) and Se(IV) contents. The limit of detection for Se(IV) was as low as 0.012 μg L^-1. The reliability of the suggested method was investigated by assaying Se(IV) and Se(VI) species in real-life water samples with satisfactory recoveries (81.1%-116%) and repeatability (RSDs below 9%).

On the use of a 2D-carbon microfiber fractionation system to improve flow-injection QTOF-HRMS analysis in complex matrices: the case of Abelmoschus manihot flower extracts

A two-dimensional microscale carbon fiber/active carbon fiber system combined with a quadrupole time of flight high-resolution mass spectrometry (2DμCFs-QTOF-HRMS) system is proposed for the rapid putative identification of polar, medium-polar and weakly polar constituents in complex matrices while strongly mitigating ionic suppression effects. The capabilities of 2DμCFs-QTOF-HRMS have been proven by analysing the composition of Abelmoschus manihot flower extracts, allowing, in a single run, the detection of 41 known substances and the presence of 6 compounds never revealed before in these samples. 2DμCFs-QTOF-HRMS has been compared with traditional HPLC-MS, showing higher versatility and a significant reduction of both analysis time (70 min to 5 min) and solvent consumption (35 mL to 1.5 mL). A comparison with the results obtained by direct flow-injection MS analyses demonstrated that 2DμCFs-QTOF-HRMS leads to a more comprehensive analysis and to improved detection sensitivity. The proposed method can be considered suitable for the rapid and comprehensive analysis of food, environmental and pharmaceutical complex samples. 2DμCFs-QTOF-HRMS can thus be considered a rapid, versatile, reliable, high-throughput and economical technique that allows for the collection of information on polar, semipolar, and weakly polar components in complex matrices.

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.

Molecularly Imprinted Polymers as Solid-Phase Microextraction Fibers for the Isolation of Selected Antibiotics from Human Plasma

The aim of this study was to examine the synthesis of novel molecularly imprinted polymer (MIP)-coated polythiophene and poly(3-methylthiophene) solid-phase microextraction fibers using the direct electropolymerization method. Synthesized SPME fibers were characterized with the use of various physicochemical instrumental techniques. MIP-SPME coatings were successfully applied to carry out the selective extraction of selected antibiotic drugs (amoxicillin, cefotaxime, metronidazole) and their metabolites (amoxycilloic acid, amoxicillin diketopiperazine, desacetyl cefotaxime, 3-desacetyl cefotaxime lactone, hydroxymetronidazole). Solid-phase microextraction parameters for the simultaneous determination and identification of target compounds were optimized using the central composite design (CCD), and they accounted for 5-15 min for desorption time, 3-10 for the pH of the desorption solvent, and 30-100 μL for the volume of the desorption solvent. High-performance liquid chromatography and mass spectrometry (MS) detectors such as quadrupole time-of-flight (Q-TOF MS) and triple quadrupole (QqQ MS) were applied to determine and to identify selected antibiotic drugs and their metabolites. The MIP-coated SPME are suitable for the selective extraction of target compounds in biological samples from patients in intensive care units.