Molecularly imprinted polymers-coated magnetic covalent organic frameworks for efficient solid-phase extraction of sulfonamides in fish.

In this study, covalent organic frameworks (COFs) were grown in situ on magnetic nitrogen-doped graphene foam (MNGF), and the resulting composite of COFs-modified MNGF (MNC) was wrapped by molecularly imprinted polymers (MNC@MIPs) for specifically capturing SAs. A magnetic solid phase extraction (MSPE) method for SAs was established using MNC@MIPs with good magnetic responsiveness. The adsorption performance of MNC@MIPs was superior to that of non-molecularly imprinted polymers (MNC@NIPs), with shorter adsorption/desorption time and higher imprinting factors. A high-efficiency SAs analytical method was developed by fusing HPLC and MNC@MIPs-based MSPE. This approach provides excellent precision, a low detection limit, and wide linearity. By analyzing fish samples, the feasibility of the approach was confirmed, with SAs recoveries and relative standard deviations in spiked samples in the ranges of 77.2-112.7 % and 2.0-7.2 %, respectively. This study demonstrated the potential use of MNC@MIPs-based MSPE for efficient extraction and quantitation of trace hazards in food.

Facile synthesis of magnetic ionic covalent organic framework and dispersive magnetic solid phase extraction of aromatic amino acid oxidation products in thermally processed foods.

Aromatic amino acid oxidation products (AAAOPs) are newly discovered risk substances of thermal processes. Due to its significant polarity and trace level in food matrices, there are no efficient pre-treatment methods available to enrich AAAOPs. Herein, we proposed a magnetic cationic covalent organic framework (Fe3O4@EB-iCOF) as an adsorbent for dispersive magnetic solid-phase extraction (DMSPE). Benefiting from the unique charged characteristics of Fe3O4@EB-iCOF, AAAOPs can be enriched through electrostatic interaction and π-π interactions. Under the optimal DMSPE conditions, the combined HPLC-MS/MS method demonstrated good linearity (R2 ≥ 0.990) and a low detection limit (0.11-7.5 µg·kg-1) for AAAOPs. In addition, the method was applied to real sample and obtained satisfactory recoveries (86.8 % âˆ¼ 109.9 %). Especially, we applied this method to the detection of AAAOPs in meat samples and conducted a preliminarily study on its formation rules, which provides a reliable basis for assessing potential dietary risks.

Innovative hierarchical porous hydrophilic molecularly imprinted resin for high-throughput detection of perfluorocarboxylic acids in milk using 96-well plate SPE-LC-MS/MS.

The accumulation of perfluorocarboxylic acids (PFCAs) in environment and foods represents a significant threat to public health due to the long-term ingestion of contaminated food. This study introduces a novel adsorbent, the hierarchical porous hydrophilic molecularly imprinted resin (HPHMIR), which was synthesized by integrating molecular imprinting techniques with hydrophilic resins. The HPHMIR, characterized by its extensive mesoporous structure (average pore width ∼9.71 nm) and favorable imprinting factors (2.6-5.0), facilitates the effective adsorption of PFCAs from complex matrices through multiple interaction mechanisms, including hydrogen bonding and electrostatic interactions. This innovative material was employed in a 96-well plate format for solid-phase extraction (SPE), and combined with LC-MS/MS, a high-throughput method for the determination of PFCAs in milk was developed. The proposed method demonstrated exceptional performance, including excellent linearity (0.48-240 ng mL-1; r ≥ 0.9986), low detection limits (0.04-0.11 ng mL-1), high precision (relative standard deviation ≤ 9.9 %), and satisfactory recovery (75.7-118.1 %). These results highlight the efficacy of the method in extracting trace levels of PFCAs from complicated sample matrices, presenting a promising alternative for monitoring PFCA contamination and advancing public health standards.

Magnetic covalent organic framework as an absorbent coupled with a portable mass spectrometer for rapid detection of malachite green and its metabolite residues.

It is important to develop specific adsorbents for malachite green and other fish drug residues. Herein, a simple strategy for synthesizing a novel magnetic covalent organic frameworks (rFe3O4@Py-COF) has been studied, and the materials were used as a magnetic absorbent for solid phase extraction (MSPE) of malachite green (MG) and its metabolite as leucomalachite green (LMG) in fishes. In this study, the mild reduction program of formic acid replacing traditional sodium borohydride as a reducing agent has been adopted to increase the stability of the framework, which can maintain the original high crystallinity and surface area of the reduced COF. The secondary amine bond is expected to be used as the reaction center for further functionalization of COF pore wall. Subsequently, rFe3O4@Py-COF (rmCOF) obtained after reduction was used as MSPE materials to detect MG and LMG by a portable mass spectrometer. After optimizing the conditions, the linearity is good within the range of 1.25∼100 µg/kg (R2≥0.9954), the limits of detection (LODs) are 0.31∼0.44 µg/kg with satisfactory recovery (85.0 %∼106.0 %). These results indicate that the assay is suitable for monitoring MG and LMG in complex aquatic foods, providing protection for food safety.

Spectrofluorimetric determination of acetone in water samples with solid-phase extraction and a new benzaldehyde derivative.

A new method is described for acetone (C(CH3)2O) determination in water samples. The method is based on the reaction with 4-(dimethylamino)benzaldehyde (DMAB) in dimethyl sulfoxide (DMSO) in slightly basic medium, resulting in a highly fluorescent compound with fluorescent wavelengths undisturbed by other common fluorescent compounds. Experimental conditions were optimized (reagents concentrations, reaction time) to reach optimal sensitivity. For the analysis of aqueous samples, a preconcentration step of acetone by solid-phase extraction (SPE) followed by an elution step in DMSO was optimized using Isolute ENV + columns. A highly satisfactory low detection limit of 0.014 µM (0.8 µg L-1) was achieved by combining these two steps, with a linear range from 0.048 to 5 µM and relative standard deviations between 5.7 % and 6.9 %. The protocol was validated on complex real water samples such as river water and wastewater, and our fluorimetric method with DMAB was in good agreement with the reference LC-UV method with DNPH.

Development of the Pipette-Tip Micro-Solid-Phase Extraction for Extraction of Rutin From Moringa oleifera Lam. Using Activated Hollow Carbon Nanospheres as Sorbents.

Herein, a micro-solid-phase extraction (µSPE) method was developed using a pipette tip for rutin extraction, employing activated hollow carbon nanospheres (HCNSs) as the sorbent. Characterization of the activated carbon nanospheres through TGA, FTIR, and SEM analysis confirmed the success of the activation process. The study demonstrated the efficacy of PT-µSPE in rutin extraction under pH 2 conditions with a standard concentration of 2 mg·L-1. The optimal mass of HCNSs was found to be 2 mg, and a loading volume of 500 µL resulted in the maximum recovery of rutin. Propan-2-ol was the best elution solvent with 15 aspirating/dispensing cycles. The correlation of determination (R 2) for the calibration curve was found to be 0.9991, and the LOD and LOQ values were 0.604 and 1.830 mg·L-1, respectively. The applicability of the method was demonstrated by extracting rutin from a complex Moringa oleifera leaf extract with the relative standard deviation (RSD) of 3.26%, thereby validating this method as feasible for the extraction of useful bioactive compounds from complex plant samples.

Recoverable and reusable light-induced multi-arm azobenzenes-Fe3O4 hybrid sorbent for enrichment of phthalate plasticizer and utilized as a SALDI substrate for the detection of 2-naphthol.

The construction, structural identifications along with compositional properties, using TEM, FT-IR, and XPS spectroscopies, of an innovative light-induced multi-arm azobenzenes based Fe3O4 magnetic nanoparticles (Azo-Fe3O4 MNPs) are being reported. Such organic (light-sensitive dendrimers-like structure), inorganic (magnet core), hybrid material has been applied as an efficient recoverable/reusable extractive sorbent for the detection of phthalate plasticizers from acetate buffer solution. The extraction study was controlled within consecutive procedures via UV-light exposure to achieve pore-size control which then further subjected for the evaluation of the analytes' retention, separation, and release as well as the detection of the phthalate pollutants using GCMS-. Various experimental conditions, such as time of extraction, salt concentration, pH, and desorption time, were studied and adjusted. Additionally, the extraction repeatability (RSD from 0.46 % to 6.12%, n = 5) of the studied sorbent was comparable to other published work. The linear range extended from 6.25 to 100 µg L-¹ and detection limits (LOD) within the range of 41- 150 ng L-1 were achieved, demonstrating good linearity with values ranging from 0.9992 to 0.9892. The inter-batch and intra-batch RSD ranged from 0.46 % to 6.12 %, respectively. Additionally, it provides effective detection of 2-naphthol when used as a SALDI substrate.

Automated kapok fiber-based pipette-tip solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry for rapid and sensitive analysis of tyrosine kinase inhibitors in plasma.

This study delineates the development of a novel automated pipette-tip solid-phase extraction (SPE) methodology, employing kapok fiber as a naturally efficient and cost-effective adsorbent for the selective extraction of eleven tyrosine kinase inhibitors (TKIs) from plasma. The uniqueness of this method lies in its assembly, where kapok fibers are ingeniously wrapped around a stainless-steel spring within the pipette tip, ensuring an obstruction-free central space for effortless solution aspiration and dispensation. This design significantly minimizes backpressure, enhancing operational efficiency and ensuring compatibility with pipettors, including the implementation of an electric pipettor to streamline the sample preparation process and facilitate automation. The method's analytical performance, rigorously validated through liquid chromatography-tandem mass spectrometry, exhibits outstanding linearity in ranges of 0.1/0.5-200 ng mL-1 (R² > 0.993), commendable accuracy (86.3%-114.8%), and consistent precision (3.4-11.3%), alongside remarkably low detection limits that span from 0.024 to 0.130 ng mL-1. The assembly of kapok fiber within the pipette tip, in this unique configuration, results in a practical, cost-effective, eco-friendly, and automated pipette-tip SPE method. This innovation signifies a significant advancement in bioanalytical methodologies, offering an efficient and sustainable approach for extracting analytes from complex biological samples. This process notably enhances both the sensitivity and selectivity of subsequent instrumental analyses.

Modification of hollow microporous organic network with polyethyleneimine for efficient enrichment of phenolic acids from fruit juice samples.

Owning to the hydrophobic characteristics of microporous organic networks (MONs), their utilizations still largely limited in non- and weak-polar analytes. To expend their applications, here we reported the synthesis of a novel hollowed H-MON-PEI1800-2 composite via sacrifice template method and subsequent modification with polyethyleneimine (PEI) for efficient solid phase extraction of polar and ionic phenolic acid (PAs) from fruit juice samples. H-MON-PEI1800-2 exhibits large surface area, rapid extraction kinetics, remarkable chemical and thermal stabilities, and provides synergistic electrostatic, π-π, hydrogen bonding, and hydrophobic interaction sites for PAs. The developed method owns low limit of detection, wide linear range, large enrichment factors, and good reusability. The recoveries of H-MON-PEI1800-2 for PAs are 1-3 orders of magnitude higher than those of commercial adsorbents like activated carbon, C18 and Oasis HLB. This work highlights the prospects of functional H-MONs for enriching polar and ionic targets from complex sample matrices.

Hollow microporous organic network fiber membrane for efficient extraction of okadaic acid from marine organisms.

Membrane-based micro-solid phase extraction (M-µSPE) has garnered great attention in sample pretreatment, suffering an inherent contradiction between permeability and adsorption capacity. In this study, a pure microporous organic network (TEB-DIB-MON) fiber membrane was prepared by combining electrostatic spinning technology, Sonogashira-Hagihara reaction and template sacrifice method. The prepared TEB-DIB-MON membrane exhibited a large specific surface area with a hollow and porous structure, thereby providing excellent solvent permeability and high adsorption capacity for okadaic acid (OA, an algal toxin). Under the optimized conditions, a sensitive analytical method was established by coupling M-µSPE with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The established method has a low detection limit (0.5 pg mL-1), a wide linear range (1.5-1000 pg mL-1, R ≥ 0.9991), and good reproducibility (RSD ≤ 9.4 %, n = 6), which was then successfully applied for OA detection in marine organisms. Trace amounts of OA (59.3-89.0 pg mL-1) was detected in the oyster and prawn samples. This work demonstrated that the excellent application potential of MON membranes in sample pretreatment, while also presents a novel synthesis strategy for MONs membranes.

Pharmacokinetics of pulmonary indacaterol in rat lung using molecular imprinting solid-phase extraction coupled with RP-UPLC.

Indacaterol, a ß2 agonist prescribed for long-term management of patients with chronic obstructive pulmonary disease and asthma. In this study the first MISPE cartridges was developed using indacaterol as a template for its selective extraction from rat lung tissues, enabling precise pharmacokinetic evaluation at the drug's site of action. A molecular imprinting polymer was synthesized using indacaterol as a template, methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linker with a molar ratio (1: 4: 20). The polymer was characterized by a high binding capacity of 9840 ± 0.86 and high selectivity with an imprinting factor of 4.53 ± 0.12. The synthesized polymer was utilized as a sorbent in solid-phase extraction to purify and extract indacaterol from lung tissue matrix. The optimum molecularly imprinted solid-phase extraction (MISPE) conditions were 20.0 mg of molecular imprinting polymer and non-imprinting polymer, acetonitrile as the loading solvent, acetonitrile: water (20: 80; by volume) as the washing solvent, and methanol: acetic acid (90: 10; by volume) as the eluting solvent. A pharmacokinetic study was performed for indacaterol in rat lungs using the synthesized and optimized MISPE cartridge as a tool for sample purification. These parameters were determined in the lung tissues of rats emphasizing the local exposure of indacaterol to its target organ. The Cmax and Tmax were 51.020 ± 2.810 µg mL- 1 and 0.083 ± 0.001 h, respectively. The AUC 0-24 and AUC0 - inf were 175.920 ± 1.053 and 542.000 ± 5.245 µg h mL- 1, respectively. The elimination rate constant was 0.014 ± 0.00012 h- 1 and the half-life time was 48.510 ± 0.012 h. This study successfully developed and optimized MISPE cartridges using indacaterol as a template, enabling precise pharmacokinetic evaluation in rat lung tissues. The cartridges demonstrated high binding capacity and selectivity, providing crucial insights into the local exposure of indacaterol at its site of action.

Determination of an Anti-Parasitic Active Pharmaceutical Ingredient in Wastewater Effluents Using Capillary Zone Electrophoresis.

Ireland has a successful pharmaceutical industry with over 100 pharmaceutical manufacturing sites across the island. Although this success has many benefits, the irreversible effects emissions from pharmaceutical manufacturing can have on the environment are a major drawback. Although known pollutants are regularly monitored with limits set out by the Environmental Protection Agency, one significant pollutant has been overlooked: pharmaceutical pollution. Detecting these pollutants and ensuring they are at a safe concentration for the environment is of utmost importance. In recent years, capillary electrophoresis is being recognised as a suitable alternative to high-performance liquid chromatography due to its many benefits such as faster analysis, water-based buffers and smaller sample volumes. In this paper, a capillary zone electrophoresis (CZE) method with a preconcentration step of solid-phase extraction was developed for an anti-parasitic active pharmaceutical ingredient (API) called ZB23. The API was successfully detected in a wastewater sample in less than 10 min using the CZE parameters of 25 mM borate buffer with a pH of 10.5, 15% MeOH, 10 kV voltage, 25 mbar for 5 s injection size, an Lt of 40 cm, an Ld of 31.5 cm and a detection wavelength of 214 nm.

Enhanced detection of catecholamines in human urine using Cis-diol-microporous organic networks with PT-SPE and HPLC-MS/MS.

A novel cis-diol-microporous organic networks (MONs-2OH) material was synthesized via room temperature and Sonogashira coupling reactions, which exhibits exceptional adsorption properties for catecholamines (CAs). MONs-2OH demonstrates robust hydrogen bonding and π-π stacking interactions, crucial for effective adsorption. The MONs-2OH was incorporated into pipette tip solid-phase extraction and developed a new method for detecting CAs in human urine using HPLC-MS/MS. Characterization of the adsorbent revealed its high stability, large specific surface area, abundant phenolic hydroxyl groups, rapid extraction speed, and superior adsorption efficiency. The method achieved a wide linear range (0.5-500 ng/mL), low detection limits (0.06-0.26 ng/mL), high accuracy (90.4 %-99.4 %), and excellent precision (RSD ≤ 10 %). Comparative studies showed MONs-2OH outperforms commercial adsorbents in terms of recovery and adsorption capacity. The results underscore the potential of MONs-2OH for rapid and sensitive CAs determination, offering significant advantages for the auxiliary diagnosis of depression and enhancing the application of PT-SPE in sample pretreatment.

Overcoming strong retention barriers of A- and V-series nerve agents on silica sorbents.

The present study explores the potential of silica solid phase extraction for gas chromatography mass spectrometric analyses of A- and V-series nerve agents. Owing to the presence of basic amidine and amine moieties, these analyte undergo strong ionic interactions with inherently acidic silica surfaces, producing poor recoveries. Subtle optimizations in the elution composition empowered the analytes to overcome the retention barriers from sorbent surfaces. Acetone containing 10 % (v/v) NH4OH effectively minimized strong analyte-sorbent interactions allowing good to excellent recoveries. Recoveries for A-series agents ranged from 88 to 96 %. VX, which is reported to be poorly recoverable from such sorbent matrices offered best data so far, reaching up to 74 % under optimized conditions. The method detection limits for the selected analytes in mass spectrometric analysis ranged from 47 to 171 ng/ml. Strong affinities of analytes towards silica sorbent were further exploited to expand the scope of analysis and establish the method's efficacy for a wide range of organic matrices. The applicability of the method to the real world applications was also validated in blind spiking exercises in diverse organic liquid samples received in 48th, 50th and 52nd proficiency tests conducted by the Organization for the Prohibition of Chemical Weapons (OPCW).

Surface amphiphilic hybrid porous polymers based on cage-like organosiloxanes for pipette tip solid-phase extraction of microcystins in water.

The occurrence of microcystins (MCs) during harmful algal blooms (HABs) represents a major threat to freshwater environments. In this work, a novel surface amphiphilic hybrid porous polymers based on cage-like organosiloxanes (PCSs) was prepared for the enrichment of MCs. The copolymerization of bifunctional amphiphilic monomers, 2-methacryloyloxyethyl phosphorylcholine (MPC) and N-benzylquininium chloride (BQN), with the cross-linker methacryl substituted polyhedral oligomeric silsesquioxane (POSS) was achieved in an ionic liquid-based porogenic medium. The hierarchical porous structure, a variety of surface functional groups and weak hydrophilicity were well characterized on the prepared materials using scanning electron microscopy, nitrogen adsorption/desorption analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, zeta potential analysis and water contact angle testing, respectively. The as-prepared surface amphiphilic PCSs was used as an adsorbent for pipette tip solid-phase extraction (PT-SPE) to enrich microcystins (MCs) from surface waters before their analysis by capillary electrochromatography (CEC) and liquid chromatography-mass spectrometry (LC-MS). Under the optimal conditions, the established PT-SPE-LC-MS method exhibited a wide linear range (10-10,000 ng L-1), low limits of detection (4.0-8.0 ng L-1) and satisfactory recoveries (89.5-102.8 %) for MCs. An adsorption mechanism involving electrostatic interactions, hydrogen bonding, hydrophilic interactions, and π-π stacking has been proposed. The findings suggest that the use of surface amphiphilic PCSs materials as adsorbents in the PT-SPE platform facilitates efficient enrichment of MCs for subsequent chromatographic analysis. These investigations offer a new perspective on the simple and uncomplicated pretreatment of complex environmental samples.

A comprehensive approach for N-nitrosamine determination in pharmaceuticals using a novel HILIC-based solid phase extraction and LC-HRMS.

N-nitrosamines (NAs) are potentially highly carcinogenic compounds that have recently been detected in traces in various drug products (DPs). Due to the different physicochemical properties of NAs and active pharmaceutical ingredients (APIs), there is a lack of appropriate analytical methods for simultaneously determining multiple NAs in various DPs. To overcome these limitations, a versatile and innovative analytical approach was developed using a unique sample clean-up procedure by solid phase extraction based on hydrophilic interaction chromatography, which retains high amounts of APIs and polar excipients while allowing NAs of interest to pass through. The samples were analyzed by liquid chromatography coupled with electrospray ionization high-resolution mass spectrometry. The proposed highly sensitive, selective, and robust method was successfully validated, resulting in excellent linearity (R2 > 0.999), accuracy (85-115 %), and precision (RSD <10 %) with adequate recoveries (>80 %), achieving limits of quantitation of at least 42.5 % of regulatory limits. Furthermore, robustness was confirmed for ten DPs (recoveries >80 % and RSD <15 % for all NAs), including those containing up to three APIs. The analytical approach was utilized to examine 26 commercially available and expired DPs. Three NAs (N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine, and N-nitroso-di-n-butylamine) were detected, only NDMA exceeded the limits in expired DPs by up to 32-fold. It was found that special care should be taken when handling samples as NDMA content can be decreased by almost 50 % if samples are not prepared immediately. The approach was tested on 59 different APIs and was confirmed as reliable tool for routine monitoring of 15 NAs in various DPs. Due to its flexibility, the method can be further adapted to the specific API of interest or extended to the newly emerging NA drug substance-related impurities to ensure the safety of DPs and thereby mitigate potential health risks.

ACFs-NH2 developed for dispersive solid phase extraction combined with Py-GC/MS for nanoplastic analysis in ambient water samples.

Accurate determination of nanoplastics (NPs) in aquatic ecosystems constitutes a challenge for which highly sensitive analytical methods are necessitated. Herein, a sample pretreatment based on self-made amino-functionalized activated carbon fibers (ACFs-NH2) dispersive solid-phase extraction (DSPE) allows for high-recovery, followed by high-sensitivity detection of NPs by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The developed methodology allowed low detection limits (20-100 µg/L) to be achieved quickly in a few steps. Under optimal conditions, ACFs-NH2 (12.5 mg) was able to recover ≥98.45 % of polystyrene (PS) nanoplastics at high concentration (100 mg/L) in 10 mL seawater. Based on the high adsorption performance of materials, the adsorption dynamics and isotherms were determined to infer the interaction mechanism of PSNPs on ACFs-NH2. After adsorption, the target on the surface of the adsorbent can be directly pyrolyzed, which can simplify the operation steps and avoid the elution of organic solvents, making the process more environmentally friendly. This strategy is feasible for the analysis of trace NPs in water systems.

Co-occurrence and spatial distribution of organic micropollutants in surface waters of the River Aconcagua and Maipo basins in Central Chile.

Organic Micropollutants (OMPs) might pose significant risks to aquatic life and have potential toxic effects on humans. These chemicals typically occur as complex mixtures rather than individually. Information on their co-occurrence and their association with land use is largely lacking, even in industrialized countries. Furthermore, data on the presence of OMPs in freshwater ecosystems in South America is insufficient. Consequently, we assessed the co-occurrence and distribution of OMPs, including pharmaceuticals, pesticides, personal care products, surfactants, and other industrial OMPs, in surface waters of two river basins in central Chile. We focused on identifying and ranking quantified chemicals, classifying their mode of actions, as well as correlating their occurrence with distinct land uses. We identified and quantified 311 compounds that occurred at least once in the River Aconcagua and River Maipo basins, encompassing compounds from urban, agricultural, industrial, and pharmaceutical sectors. Pharmaceuticals were the most frequently occurring chemicals, followed by pesticides, personal care and household products. OMPs with neuroactive properties dominated surface waters in Central Chile, along with OMPs known to alter the cardiovascular and endocrine systems of humans and aquatic animals. Finally, we observed positive correlations between agricultural and urban land uses and OMPs. Our findings represent a step forward in extending current knowledge on the co-occurrence patterns of OMPs in aquatic environments, particularly in developing countries of the southern hemisphere.

Magnetic solid-phase extraction of amoxicillin and doxycycline from water and urine samples based on cetylpyridinium chloride-modified Fe3O4 nanoparticles followed by spectrophotometric determination.

This research describes an easy, rapid, and inexpensive magnetic solid-phase extraction (MSPE) approach employing Fe3O4 magnetic nanoparticles modified with cetylpyridinium chloride (Fe3O4@CPC/MNPs) for extracting amoxicillin (AMX) and doxycycline (DOX) after derivatization with 4-chloroaniline as a color reagent. The azo-coupling of AMX and DOX with the color reagent in the alkaline medium caused yellow and yellow-orange azo dyes with maximum absorption wavelengths of 435 and 438 nm, respectively. The UV-Vis spectroscopy was utilized to determine the target analyte after the extraction procedure. Good linearities (R2 > 0.99) in the concentration ranges of 0.03-4.50 and 0.05-6.00 µg/mL were obtained for AMX and DOX, respectively. The experimental detection limits of AMX and DOX were obtained as 0.01 and 0.02 µg/mL, respectively. The developed approach was effectively applied to pre-concentrate and quantify AMX and DOX in environmental water and urine samples.

Magnetic conjugated microporous polymer for rapid extraction and sensitive analysis of environmental endocrine disruptors in environmental waters and dairy products.

BACKGROUND: Environmental endocrine disruptors (EEDs) are a class of new pollutants that are diffusely used in the medical industry and animal husbandry. In view of toxicity concerns, elevated levels of EEDs in the environment and food, which cause potential harm to human beings and ecosystems, must be monitored. Determination of EEDs contaminants to ensure environment and food safety has became a major concern worldwide, it is also a challenging task because of their trace level and probable matrices interference. Thus, developing rapid adsorption and efficient analysis methods for EEDs is apparently necessary. RESULTS: A magnetic conjugated micro-porous polymer (Fe3O4@TbDt) was designed and synthesized, which was endowed with large specific surface area, rich functional groups and magnetic responsiveness. The material showed high extraction efficiency for EEDs via magnetic solid-phase extraction (MSPE). The quantum chemistry calculations showed the adsorption mechanism of Fe3O4@TbDt on EEDs mainly included electrostatic interactions, van der waals forces (N-H … π interaction, C-H … π interaction), and multiple hydrogen bonds. Finally, a trace analysis method for nine EEDs was established combined with HPLC-MS/MS under optimized MSPE conditions. The method showed a good linearity (R2 ≥ 0.996), low limits of detection (0.25-5.1 ng L-1), high precision (RSD of 1.1-8.2 %, n = 6). The applicability of this method was investigated by analyzing four water samples and two dairy products, and satisfactory recovery rates (82.1-100.7 %) were obtained. The proposed method showed the potential for the analysis of EEDs residues in food and environmental samples. SIGNIFICANCE: The developed MSPE method based on conjugated micro-porous polymers (CMPs) is simple, green, and efficient compared to existing techniques. The application of CMPs provides a new idea for preparing versatile sample pre-treatment materials. What's more, this work has certain reference value for addressing of EEDs residues in the environment and food.