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• Establishing a method for determination of CaHMB in special medical formula food and sports nutrition food by HPLC. • SPE purification method was firstly introduced to analyze real samples. • Good purification effect, high separation specificity, good repeatability and accuracy. Calcium β‑hydroxy-β-methylbutyrate (CaHMB) can promote muscle growth, prevent muscle atrophy, and enhance immunity, therefore, it is widely used as a nutritional supplement in special medical formula food and sports nutrition food. Many methods for the detection of CaHMB have been reported, but the pretreatment method for these reported literatures directly involves extraction using hydrochloric acid solution, without any purification steps. A method for accurately determining CaHMB in special medical formula food and sports nutrition food was established for the first time using solid-phase extraction (SPE) purification and high-performance liquid chromatography method (HPLC). The samples were extracted and precipitated protein using methanol-water solution, purified using SPE method and analyzed by HPLC on diode array detector (DAD) mode under external standard method. The method obtained excellent calibration linearity (r2>0.9993) and a satisfactory analysis of the targeted compound, which were evaluated with calibration standards over the range of 0.020–2.00 mg/mL. The limit of quantifications (LOQs), which defined as the lowest spiking level, were set at 0.4 g/100 g (special medical formula food) and 1.0 g/100 g (sports nutrition food). The average recoveries were within 92.9–104% for the analytes, and the relative standard deviations (RSDs) were below 3.93%, measured at low, medium, and high concentrations. Moreover, the positive sample analysis results indicated that CaHMB was detected on 10 real special medical formula food and sports nutrition food products, the contents of which were generally consistent with their labeled values, with measured values ranging from 97.1 % to 119 % of the labeled values. These results suggested that the developed highly sensitive and specific method is highly feasible for monitoring of the target analyte in special medical formula food and sports nutrition food. [ABSTRACT FROM AUTHOR]

• An available way to produce iCOFs by functionalizing COFs with ILs. • Two ILs modified SiO 2 @COF to synthesize two SiO 2 @iCOF. • SiO 2 @iCOF-2 gave best extraction effect for estrogens than others. • The extraction mechanisms contained π-π, hydrogen-bond and electrostatic interactions. • An online SPE-HPLC-DAD method for the detection of estrogens in water or aqueous samples. A covalent organic framework (COF) was gown on porous silica with 1,3,5-tri(4-aminophenyl)benzene and 2,5-divinyl-1,4-phenyldiformaldehyde as monomers, and two ionic liquids were grafted to COF by a click reaction. The materials before and after the modification of ionic liquids were separately packed into solid-phase extraction columns (10 × 4.6 mm, i.d.), which were coupled with liquid chromatography to construct online analysis systems. The extraction mechanisms of polycyclic aromatic hydrocarbons, bisphenols, diphenylalkanes and benzoic acids were investigated on these materials. There were π-π, hydrogen-bond and electrostatic interactions on ionic liquid-functionalized sorbents. After the comparison among these materials, the best sorbent was used, and the analytical method was established and successfully applied to the detection of some estrogens from actual samples. For the analytical method, the detection limit was as low as 0.005 μg L−1, linear range was as wide as 0.017–10.0 μg L−1, and enrichment ratio was as high as 3635. The recoveries in actual samples were 70 %-129 %. [ABSTRACT FROM AUTHOR]

• Enhanced & innovative sample preparation approach, to overcome the practical limitations for extraction of selective low-level analyte(s) from large volume of syrups in LLE. • Handling large volume syrups in analysis is challenging as it has low drug content. • Trace level nitrosamine analysis require high levels of sensitivity and precision. • Using solid-phase extraction for enrichment and selective extraction of nitrosamines with minimum sample matrix interference. • Analytical method to achieve the safety standards set by ICH and global regulators. A quantitative testing method was developed for the analysis of low molecular weight (small molecules) nitrosamine impurities in cough syrups using solid phase extraction (SPE) on strong cation-exchange functionalized polymeric sorbent cartridges followed by gas chromatography-mass spectrometry. The matrix spike recoveries of the nitrosamine impurities from the cough syrup samples was observed to be within the range of 90 %-120 %. Limit of detection (LOD) achieved for N Nitrosodimethylamine (NDMA) and N Nitroso morpholine (NMOR) was about 0.1 ng/mL while the LOD for N Nitrosodiethylamine (NDEA), N Nitrosodiisopropylamine (NDIPA) and N Nitrosoisopropylethylamine (NIPEA) impurities was about 0.02 ng/mL. The method was evaluated and found to meet the acceptable criteria as per the ICH Q2 guidelines for a working concentration range of 0.02 ng/mL to 1.2 ng/mL for the analyzed impurities. The selectivity of the nitrosamine impurities against the presence of drug product was established using multiple reaction monitoring (MRM) transitions during analysis. [ABSTRACT FROM AUTHOR]

• Substituted para-phenylenediamine quinones (PPD-Qs) are harmful to organisms. • Cysteine functional covalent organic framework (Cys-COF) is designed. • Cys-COF has good adsorption effect on PPD-Qs from complex media. • The adsorptive mechanism of hydrogen-bonded ring is revealed. • PPD-Qs can transfer from environment to fish. N,N ′-Substituted p -phenylenediamine quinones (PPD-Qs) are the emerging toxicant, which transform from the rubber tire antioxidant N,N ′-substituted p -phenylenediamines (PPDs). Because of their potential toxic and widespread occurrence in the environment, PPD-Qs have received great attention. However, efficiently extracting PPD-Qs from complex samples is still a challenge. Herein, a cysteine functional covalent organic framework (Cys-COF) designed according to the "donor-acceptor" sites of hydrogen bonding of PPD-Qs was synthesized via click reaction and then used as solid-phase extraction (SPE) adsorbent. Cys-COF can form the seven-member ring adsorption structure with PPD-Qs via hydrogen bonding. The adsorption mechanism was tentatively revealed by density functional theory (DFT). After optimizing the Cys-COF-SPE parameters, PPD-Qs were efficiently extracted from water, soil, sediment, and fish, followed by detection using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The Cys-COF-SPE-UHPLC-MS/MS method exhibited ideal linearity (R2 ≥ 0.9932), high relative recoveries (80.4–111 %), and low limits of detection (0.0001–0.0013 ng mL−1). In addition, the bioconcentration kinetics in goldfish provides a feasible platform to investigate the toxicity and accumulated ability of PPD-Qs. [ABSTRACT FROM AUTHOR]

• CMP-1 was synthesized by Sonogashira-Hagihara cross-coupling. • CMP-1 exhibited a large surface area of 788 m2·g−1 and abundant micropore structures. • This SPE method was applied to quantify NEOs in groundwater, tap water, and surface water. • The material shows excellent accuracy and application in NEOs monitoring. Conjugated microporous polymers (CMPs) have unique characteristics and have been used in a range of fascinating applications in separation sciences. In this study, a CMP, designated as CMP-1, was synthesized via the Sonogashira-Hagihara coupling reaction using 1,3,5-triphenylbenzene and 1,4-dibromobenzene as building blocks. CMP-1 features a large surface area, abundant micropore structures, and excellent stability, making it a promising solid-phase extraction adsorbent for the efficient enrichment of neonicotinoid insecticides (NEOs). Under the optimized conditions, CMP-1 was combined with high-performance liquid chromatography and diode array detection to enable the detection of NEOs with a wide linear range (0.5–200 μg·L–1), a low detection limit (0.26–0.58 μg·L–1), and acceptable precision. The developed method was applied to determine spiked NEOs in three types of environmental water samples, with recoveries of 73.7%–112.0% and relative standard deviations of 0.6%–9.4%. [ABSTRACT FROM AUTHOR]

• Influence of crosslinker/porogen ratio in SPE performance of polymer monoliths. • Simple method to adjust pore structure in robust materials for sample preparation. • Efficient preconcentration of bisphenols (EF = 279-375). Polymer monoliths can be polymerised within different molds, but limited options are available for the preparation of free-standing polymer monoliths for analytical sample preparation, and in particular, solid-phase extraction (SPE). Commercial melamine-formaldehyde sponges can be used as supports for the preparation of polymer monoliths, due its flexibility, giving various shapes to monoliths. Herein, the crosslinker/porogen ratio of highly porous sponge-nested divinylbenzene (DVB) polymer monoliths has been evaluated. Monoliths prepared using different crosslinker/porogen ratios were applied to the extraction of bisphenol F, bisphenol A, bisphenol AF, and bisphenol B. Monoliths containing 50 wt % DVB and 50 wt % porogens presented the highest recovery of bisphenols. Under the optimised conditions, the developed method showed a linear range between 2.5 µg L−1 and 150 µg L−1 for BPA and BPAF, and between 5 µg L−1 and 150 µg L−1 for BPB and BPF. The limits of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) ranged from 0.36 µg L−1 to 1.09 µg L−1, and from 1.20 µg L−1 to 3.65 µg L−1, respectively. The recoveries for spiked bisphenols (10 µg L−1) in tap water and water contained in a polycarbonate containers were between 82 % and 114 %. [ABSTRACT FROM AUTHOR]

• Consider a harmonious balance of adsorption capacity, desorption efficiency, and compatibility with different biochar types in solid-phase extraction (SPE). • Nitrogen-doped chlorella biochar reduces irreversible adsorption while enhancing bamboo biochar's selectivity. • H+ proton equilibrium influences biochar's adsorption-desorption balance. Biochar, a sustainable sorbent derived from pyrolyzed biomass, has garnered attention for its efficacy in solid-phase extraction (SPE) of antibiotics, with a particular focus on tetracyclines (TCs). Despite its recognized potential, the intricate separation mechanisms operative in biochar-based SPE systems have not been fully deciphered. This investigation contrasts chlorella biochar against commercial bamboo biochar, harnessing an array of analytical methodologies-microstructure characterization, adsorption thermodynamics, competitive adsorption kinetics, H+ back titration, and selectivity adsorption studies-complemented by a Box-Behnken design for the optimization of chlorella/bamboo-SPE and subsequent application in the analysis of animal-derived foodstuffs. The study unveils that a hybrid sorbent, integrating nitrogen-doped microporous chlorella biochar with mesoporous bamboo biochar in a 95/5 mass ratio, markedly diminishes irreversible adsorption while enhancing selectivity, surpassing the performance of single biochar SPE systems. The elucidated separation mechanisms implicate a partition model, propelled by oxygen-rich functional groups on chlorella biochar and the rapid adsorption kinetics of bamboo biochar, all orchestrated by electrostatic interactions within the mixed biochar framework. Moreover, the synergy of mixed biochar-SPE with high-performance liquid chromatography (HPLC) demonstrates exceptional proficiency in detecting TCs in animal viscera, evidenced by recovery rates spanning 80.80 % to 106.98 % and RSDs ranging from 0.24 % to 14.69 %. In essence, this research not only sheds light on the multifaceted factors influencing SPE efficiency but also propels the use of biochar towards new horizons in environmental monitoring and food safety assurance. [Display omitted] [ABSTRACT FROM AUTHOR]

• A simple on-site SPE extraction is proposed for analyzing rotenone in lakes. • Immediate extraction limits the degradation of rotenoids in samples before analysis. • GC-MS analysis enabled monitoring rotenoid degradation after piscicide treatments. • LOQs under 2 µg/L ensure adequate analysis below the no-effect levels of rotenone. The introduction of invasive fish species to aquatic ecosystems has been demonstrated to cause disastrous ecological effects. Current conservation strategies regard rotenone-containing piscicide formulations, such as commercial product CFT Legumine, as a potentially viable alternative to the cumbersome traditional approaches to fish eradication. This consideration relies on the fast degradation of rotenone and its relatively rapid dissipation from the environment. Piscicide treatments in fragile aquatic ecosystems should thus monitor not only rotenone concentrations following application, but also other byproducts and degradation products. We present a methodology for the analysis of rotenoids in fresh and brackish waters that addresses two main challenges: the accurate determination of applied concentrations in different salinity concentrations by performing a simplified on-site solid-phase extraction, overcoming the fast degradation of rotenone in sample storage conditions, and the selective analysis of rotenoid byproducts and degradation products by gas chromatography coupled to mass spectrometry. Limits of quantification were below the ecological no-effect concentration of rotenone (2 µg/L) and average recoveries exceeded 80%. Accuracy (compared to expected values) and precision (deviation of replicates) ranged from 78 to 103% and 3 to 14%, respectively, across various rotenoid concentrations. These metrics are more than satisfactory for the intended application of this simplified procedure. The method was applied to piscicide-treated samples, revealing significant and fast degradation of parent rotenoids in storage conditions, as well as a non-negligible accumulation of rotenone in the particulate fraction of water that could impact the effectivity of eradication efforts. [ABSTRACT FROM AUTHOR]

• Computational simulation and spectrophotometric analysis were exploited to screen monomers of MIPs. • The dummy template MIPs were successfully prepared by precipitation polymerization method. • The obtained MIPs exhibited favorable high adsorption capacity and fast equilibrium rate towards 3 p-toluene sulfonate esters. • Solid-phase extraction process based on MIPs was explored. Sulfonate esters, one class of genotoxic impurities (GTIs), have gained significant attention in recent years due to their potential to cause genetic mutations and cancer. In the current study, we employed the dummy template molecular imprinting technology with a dummy template molecule replacing the target molecule to establish a pretreatment method for samples containing p-toluene sulfonate esters. Through computer simulation and ultraviolet–visible spectroscopy analysis, the optimal functional monomer acrylamide and polymerization solvent chloroform were selected. Subsequently, a dummy template molecularly imprinted polymer (DMIP) was prepared by the precipitation polymerization method, and the polymer was characterized in morphology, particle size, and composition. The results of the adsorption and enrichment study demonstrated that the DMIP has high adsorption capability (Q = 7.88 mg/g) and favorable imprinting effects (IF = 1.37); Further, it could simultaneously adsorb three p-toluene sulfonate esters. The optimal adsorption conditions were obtained by conditional optimization of solid-phase extraction (SPE). A pH 7 solution was selected as the loading condition, the methanol/1 % phosphoric acid solution (20:80, v/v) was selected as the washing solution, and acetonitrile containing 10 % acetic acid in 6 mL was selected as the elution solvent. Finally, we determined methyl p-toluene sulfonate alkyl esters, ethyl p-toluene sulfonate alkyl esters, and isopropyl p-toluene sulfonate alkyl esters in tosufloxacin toluene sulfonate and capecitabine at the 10 ppm level (relative to 1 mg/mL active pharmaceutical ingredient (API) samples) by using DMIP-based SPE coupled with HPLC. This approach facilitated the selective enrichment of p-toluene sulfonate esters GTIs from complex API samples. [ABSTRACT FROM AUTHOR]

The release of harmful compounds, particularly dangerous metal ions, into the environment has drawn deep concern from the scientific community. Therefore, it has become common in research to evaluate and quantify the harmful concentrations in the presence of these metal ions in several real samples (food, water, and biological samples). To increase sensitivity and lessen the impact of the matrix, sample pretreatment is a helpful strategy to implement before analysis. The limitations of conventional methods have been recently significantly reduced by developing new analytical approaches such as microextraction techniques. The miniaturization of conventional solid-phase extraction (SPE) led to solid-phase microextraction (SPME), drastically reducing both adsorbent use and extraction phase volume. SPME is defined in the present context as a modified extraction technique that employs a portable syringe system attached to micropipette tips. The SPME is considered one of the most appropriate sample preparation tools due to its compatibility with different detection techniques for different metal ions. The current review focuses on SPME based on a portable syringe (attaches to a micropipette tip) system because it has many advantages over conventional solid-phase extraction. It can be designed very simply in a syringe system, a very small quantity of the sorbent has to be kept in the tip, tube, or inside a syringe as a plug and combined with various analytical instruments. Many researchers have designed their own by using homemade tips packed with a sorbent to increase extraction capability and selectivity. According to the current review, there is a lot of potential for increasing the efficacy and efficiency of metal ion extraction from complicated matrices using portable syringe SPME. Studies have shown that when compared to conventional approaches, it performs better in terms of sensitivity, selectivity, and user-friendliness. Furthermore, its application to a wider range of sample types has been enhanced by the flexibility in constructing unique sorbent tips. Conclusively, the developments in portable syringe SPME have addressed several limitations of conventional techniques, positioning it as a robust and versatile tool for environmental monitoring and analysis of hazardous metal ions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

• Pompon mum-like molecularly-imprinted ionic COF nanocomposites were prepared. • The prepared material exhibits higher adsorption capacity and faster kinetic. • The molecular imprinting factors range from 2.8 to 6.7. • A sensitive SPE-HPLC-UV method was developed for the detection of trace NSAIDs. Molecularly imprinted ionic covalent organic framework nanocomposites (MI-IC-COF@SnO 2) were prepared as potential adsorbents for the enhanced adsorption of nonsteroidal anti-inflammatory drugs (NSAIDs) from aqueous solution. The resulting material exhibited a pompon mum-like structure, featuring a large surface area, and well-defined mesopores. The presence of uniform positive ions within the three-dimensional skeleton of MI-IC-COF@SnO 2 facilitated a rapid adsorption rate and high adsorption capacity for target analytes. Thermodynamic fitting revealed the adsorption process of NSAIDs to be feasible, endothermic, and spontaneous. Additionally, the adsorbent material exhibited respectable selectivity, as evidenced by imprinting factor values ranging from 2.8 to 6.7. Utilizing MI-IC-COF@SnO 2 as the sorbent, a solid-phase extraction method coupled with high-performance liquid chromatography-ultraviolet detection (SPE-HPLC-UV) was developed and optimized. The proposed method demonstrated good linear range with determination coefficients of 0.998–0.999, and low limit of detection (0.18–1.35 µg L−1). Recoveries of NSAIDs in urine and river water samples were 78.1 %–106.1 %, with relative standard deviations lower than 12.5 %. This rapid and sensitive method enables the determination of NSAIDs at trace levels in complex matrices, providing reliable and reproducible results. [ABSTRACT FROM AUTHOR]

• Theoretical investigation on the noncovalent MIPs used in aqueous environment. • A modified suspension polymerization was proposed to synthesize 2,4- d -MIP. • 2,4- d -MIP has high adsorption capacity, excellent selectivity and reusability. • 2,4- d -MIP shows strong anti-protein adsorption in aqueous environment. Herein, 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a model template in a rational design strategy to produce water-compatible noncovalent imprinted microspheres. The proposed approach involved computational modelling for screening functional monomers and a simple method for preparing monodisperse and highly cross-linked microspheres. The fabricated non-imprinted polymer (NIP) and 2,4- d -imprinted polymer (2,4- d -MIP) were characterised, and their adsorption capabilities in an aqueous environment were evaluated. Results reveal that the pseudo-second-order kinetics model was appropriate for representing the adsorption of 2,4-D on NIP and 2,4- d -MIP, with R2 values of 0.97 and 0.99, respectively. The amount of 2,4-D adsorbed on 2,4- d -MIP (97.75 mg g −1) was considerably higher than those of phenoxyacetic acid (35.77 mg g −1), chlorogenic acid (9.72 mg g −1), spiramycin (1.56 mg g −1) and tylosin (1.67 mg g −1). Furthermore, it exhibited strong resistance to protein adsorption in an aqueous medium. These findings confirmed the feasibility of the proposed approach, providing a reference for the development of water-compatible noncovalent imprinted polymers. [ABSTRACT FROM AUTHOR]

• DLP 3D printing – using resin and C18 silica suspension for pharmaceutical analysis. • Study refines printing, material, and extraction parameters for enhanced performance. • Cost-effective, quick and inclusive: cheap 3D-printer with widely available materials. • 3D printing fabricates extraction devices – shaped as needed, with C18 silica particles. • 3D printed devices exhibit precise and accurate analytical performance. In recent years, there has been an increasing worldwide interest in the use of alternative sample preparation methods. Digital light processing (DLP) is a 3D printing technique based on using UV light to form photo-curable resin layer upon layer, which results in a printed shape. This study explores the application of this technique for the development of novel drug extraction devices in analytical chemistry. A composite material consisting of a photocurable resin and C18-modified silica particles was employed as a sorbent device, demonstrating its effectiveness in pharmaceutical analysis. Apart from estimating optimal printing parameters, microscopic examination of the material surface, and sorbent powder to resin ratio, the extraction procedure was also optimised. Optimisation included the type and amount of sample matrix additives, desorption solvent, sorption and desorption times, and proper number of sorbent devices needed in extraction protocol. To demonstrate this method's applicability for sample analysis, the solid-phase extraction followed by gas chromatography coupled with mass spectrometry (SPE-GC–MS) method was validated for its ability to quantify benzodiazepine-type drugs. This evaluation confirmed good linearity in the concentration range of 50–1000 ng/mL, with R2 values being 0.9932 and 0.9952 for medazepam and diazepam, respectively. Validation parameters proved that the presented method is precise (with values ranging in-between 2.98 %-7.40 %), and accurate (88.81 % to 110.80 %). A negative control was also performed to investigate possible sorption properties of the resin itself, proving that the addition of C18-modified silica particles significantly increases the extraction efficiency and repeatability. The cost-effectiveness of this approach makes it particularly advantageous for single-use scenarios, eliminating the need for time-consuming sorbent-cleaning procedures, common in traditional solid-phase extraction techniques. Future optimisation opportunities include refining sorbent size, shape, and geometry to achieve lower limits of quantification. As a result of these findings, 3D-printed extraction devices can serve as a viable alternative to commercially available SPE or solid-phase microextraction (SPME) protocols for studying new sample preparation approaches. [ABSTRACT FROM AUTHOR]

• Synthesis of core-shell QA-PDNV@MWCNTs in a controlled manner. • High cleanup efficiencies toward GLY and its metabolites in plasma samples were obtained. • Effect of MWCNTs content on the QA-PDNV@MWCNTs surface was significant. • Confirming for GLY poisoning based on both GLY prototype and its four metabolites. The present study focused on the pretreatment and detection of GLY and its four metabolites AMPA, N-acetyl AMPA, N-methyl GLY and N-acetyl GLY in plasma samples. Multi-walled carbon nanotube-modified quaternary amine-functionalized polymers (QA-PDNV@MWCNTs) were synthesized in a controlled manner by self-assembly, and its morphology and composition were extensively characterized. The QA-PDNV@MWCNTs microspheres were then used as an SPE adsorbent for the preparation and rapid determination of GLY and its four metabolites in plasma samples combined with ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC HRMS). The SPE conditions based on QA-PDNV@MWCNTs were optimized for GLY and its metabolites to obtain the best purification efficiency. The experimental results show that when the adsorbent contains 8% MWCNTs, it can balance the adsorption of target analytes and the purification performance of the adsorbent for impurities. In addition, this study compared the QA-PDNV@MWCNTs based SPE method with the commercial Waters Oasis MAX SPE cartridge and the results showed that the developed method in this study has better resistance to matrix interference. Under optimal conditions, the recoveries of GLY and its metabolites spiked in plasma were 82.6–99.4 % with relative standard deviations (RSDs) of 1.0–7.8 %. The limits of detection (LODs, S/ N ≥ 3) and limits of quantification (LOQs, S/ N ≥ 9) of the method were 0.05–0.33 μg/L and 0.15–1.00 μg/L, respectively. Finally, the developed QA-PDNV@MWCNTs based SPE-UPLC HRMS method was used to confirm GLY poisoning not only on the basis of the detection of the GLY prototype, but also on the basis of its four metabolites. [ABSTRACT FROM AUTHOR]

• A bamboo biochar was introduced to prepare a composite monolithic adsorbent;. • The prepared composite adsorbent showed excellent matrix-removal ability;. • The adsorbent showed good reversible retention ability for the two coumarins;. • The SPE column can be used for no less than 100 times with good performance. A monolithic adsorbent was designed aiming to the structure of osthole and columbianadin, and fabricated using diallyl phthalate as the monomer and ethylene dimethacrylate as the crosslinker with the addition of bamboo biochar, via polymerization reaction in a stainless-steel tube. The prepared composite adsorbent packed in the tube was used as a solid-phase extraction column for the extraction and determination of two coumarins (osthole and columbianadin) in Angelicae Pubescentis Radix , combing with a C18 analytical column through an HPLC instrument, which show excellent matrix-removal ability and good selectivity to osthole and columbianadin. Furthermore, the present adsorbent shows good applicability, which was used for the extraction of osthole from Duhuo Jisheng Pill. Compared to the commercial C18 and phenyl adsorbent, the present adsorbent own better selectivity and higher resolution. These results attributed to the enhanced specific surface area (141 m2/g) and enriched interaction sites of the resulting composite adsorbent, due to the doping of bamboo biochar, which can produce hydrogen bond, dipole-dipole, π-π and hydrophobic force interactions with the osthole and columbianadin. The methodology validation indicated that the present method showed good precision and good accuracy, and the composite adsorbent showed good preparative repeatability, which can be reused for no less than 100 times with the relative standard deviation ≤4.6 % (n = 100). The present work provided a simple and efficient method for the extraction and determination osthole and columbianadin from Angelicae Pubescentis Radix. [ABSTRACT FROM AUTHOR]

• Ordered macroporous metal-organic framework (OM-ZIF-8) were fabricated. • OM-ZIF-8 can efficiently adsorb aflatoxins (AFs) via multiple forces. • OM-ZIF-8 was used as the solid-phase extraction (SPE) adsorbent. • OM-ZIF-8-SPE method can efficiently enrich AFs from milk products. Aflatoxins (AFs) exhibit hepatotoxicity, immunotoxicity, and carcinogenicity, and their detection in food has attracted widespread concern. An ordered macroporous metal-organic framework (OM-ZIF-8) based on solid-phase extraction (SPE) was used to extract six AFs from milk products. The SPE conditions, including eluting solvent, eluting volume, amounts of OM-ZIF-8, pH of loading solution, loading solvent, ionic strength, loading flow rate, and elution flow rate, were exhaustively optimized. Under optimal parameters, the six AFs were detected by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The OM-ZIF-8 exhibited satisfactory AFs extraction performance through ordered macropore structure, π-π interaction, coordination interaction, and electrostatic interaction. Furthermore, linearity in the range of 0.01–100 ng mL−1 with low detection limits of 0.002–0.0150 ng mL−1 was obtained, and the relative recoveries of AFs were 80.3–110 % with relative standard deviation ≤8.7 %. Thus, this research provides a promising platform for the analysis of trace AFs in complex foods. [ABSTRACT FROM AUTHOR]

• Combining of two extraction techniques into one working system was used. • Molecularly imprinted polymers as solid phase extraction sorbent was applied. • Synthesised sorbents was tested as acceptor phase for membrane extraction. • Highly-selective extraction (towards template molecules) was observed. • The developed method was used to determine phytoestrogens in urine samples. An efficient sample clean-up and preconcentration procedure for phytoestrogens analysis in urine has been developed. It was based on a combination of solid phase extraction with hollow-fiber supported liquid membrane and molecularly imprinted beads (MIPs-HF-SLM-SPE). The molecularly imprinted polymers (MIPs) were synthesized by precipitation polymerization technique with biochanin A (BCA) as a template, giving narrowly dispersed microspheres with a regular shape. As the functional monomer, (dimethylamino)ethyl methacrylate (-DEM) turned out to be better than methacrylic acid (MAA) to get the best-imprinted effects. The MIPs used as sorbents in the MIPs-HF-SLM-SPE extraction process exhibited excellent binding selectivity for BCA, in comparison to non-imprinted polymers as well as its structural analogs (genistein and daidzein). Finally, the developed method was used to detect BCA in urine. Under optimal extraction conditions, the recovery of BCA in urine samples (using 4.5 mL sample spiked with 10 μg L−1) was over 41%, with a coefficient of variation (CV) < 6.6% (n = 5). The detection limit (LOD) and quantification limit (LOQ) for BCA analysis in urine were 0.41 and 1.36 μg L−1, respectively. [ABSTRACT FROM AUTHOR]

• AMPAs, markers of nerve agents were extracted by polymeric thin film. • In-situ derivatization and the HS-SPME were performed on poly(META) thin film. • AMPAs were detected by GC–MS without an elution step. • The method was successfully applied to the 35th OPCW proficiency test sample. A headspace solid-phase microextraction (HS-SPME) method, involving solid-phase extraction and in-situ derivatization using polymeric thin film, was developed for the gas chromatography-mass spectrometry (GC–MS) analysis of the degradation products of nerve agents. The solid-phase extraction (SPE) was performed using poly([2-(Methacryloyloxy)ethyl]trimethylammonium chloride) film on a gold plate prepared via surface-initiated polymerization. The extracted analytes were directly derivatized with N,O -bis(trimethylsilyl)trifluoroacetamide (BSTFA) on the plate. Various parameters like fiber type, headspace time, temperature, and amount of BSTFA were optimized. Under the optimized conditions, the relative standard deviations (RSDs) were in the range 7.0–13.1% and the limits of detection (LODs) were measured to be between 10 and 20 pg mL−1. The application of the developed method was tested using the 35th Organization for Prohibition of Chemical Weapons (OPCW) proficiency test sample. [ABSTRACT FROM AUTHOR]

Highlights • Preparation and evaluation of DMIP for imidazole fungicides using DCE as the fragment dummy template. • High selective solid phase extraction of CBZ, CMZ and MNZ from river water. • Good recovery and reproducibility of the developed DMISPE-HPLC method. • Superiority selectivity compared to commercial MCX sorbent. Abstract Dummy molecularly imprinted polymer (DMIP) for imidazole fungicides was prepared for the first time using alpha-(2,4-Dichlorophenyl)-1H-imidazole-1-ethanol (DCE) as the fragment template. The imprinting selectivity of DCE-DMIP was evaluated for climbazole (CBZ), clotrimazole (CMZ) and miconazole (MNZ) by liquid chromatography, imprinting factors of 10.9, 10.8 and >10.7 were achieved, respectively. Heterogeneous binding sites were found in the DCE-DMIP, the corresponding saturation capacity and dissociation constant for the high affinity binding sites were 13.05 μmol g–1 and 0.4701 mmol L–1. High efficient method based on dummy molecularly imprinted solid phase extraction (DMISPE) coupled with HPLC was established for the selective enrichment of CBZ, CMZ and MNZ in river water using DCE-DMIP as sorbent. DMISPE conditions including sample loading pH/volume, selective washing and elution solvents were carefully optimized. The developed method showed good recoveries (84.2–95.0%) and precision (RSDs 1.7–5.0%, n = 5) for samples spiked at two different concentration levels (0.5 and 2.5 μg L–1). The detection limits were ranged from 0.023 to 0.031 μg L–1. The results demonstrated good potential of this method for sample pretreatment of azole fungicides in environmental water samples. [ABSTRACT FROM AUTHOR]

Highlights • Hydrophilic sulfonamides molecularly imprinted polymers were prepared. • The quantification method was established for trace level sulfonamides detection. • The whole pretreatment process avoided organic solvents consumption. Abstract A water-compatible molecularly imprinted polymer (MIP) was prepared by combining reversible addition-fragmentation chain transfer (RAFT) with reflux precipitation polymerization (RPP) for solid-phase extraction (SPE) coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS) to detect six sulfonamides (SAs) in animal-derived foods and water samples. The SEM images indicated the spherical structure of MIP materials. In water medium, MIPs still performed good specific adsorption for SAs. Under the optimized detection conditions, the proposed method offered good linearity (R2 > 0.996) for the six SAs with relative standard deviation (RSD) for ten replicate extractions of 1.64%–4.68%, limits of detection (S/N = 3) of 0.02 μg L−1-0.1 μg L−1 and recoveries of 63.49%–115.72%. Besides, the whole extract process avoided organic solvent consumption, and trace sulfadiazine residues were found in the pork sample at similar concentration of 3.57 and 3.79 μg kg-1 using the MIP-SPE method and commercial Oasis HLB cartridge, respectively. It is confirmed the method could be applied to quantitative detect the trace residue sulfonamides in animal-derived samples and water samples. [ABSTRACT FROM AUTHOR]

• A stable core-shell MOF@COF composite was synthesized and utilized as SPE adsorbent. • The covalent integration of hydrophobic COF shell successfully enhanced the hydrophobicity of MOF core. • The excellent extraction efficiency was attributed to the presence of multiple interactions. • A sensitive method for the quantification of flavonoids in grape juice and honey samples was developed. Hydrophobization and stability is crucial for the practical application of most metal-organic frameworks (MOFs) in extraction technique. In this study, a stable core-shell MOF@COF composite (NH 2 -MIL-101(Fe)@TAPB-FPBA-COF) was successfully prepared by Schiff base reaction and applied to solid-phase extraction (SPE) of hydrophobic flavonoids. Notably, the TAPB-FPBA-COF shell acts as a hydrophobic "shield", which not only improves the hydrophobicity and stability of hydrophilic NH 2 -MIL-101(Fe), but also makes the extraction efficiency of flavonoids from MOF@COF composite significantly higher than that of pure NH 2 -MIL-101(Fe) and TAPB-FPBA-COF. In addition, a sensitive analytical method with excellent linearities (0.1–500 ng mL−1, R2 ≥ 0.9967), low limits of detection (0.02–0.04 ng mL−1 for water; 0.04–0.07 ng mL−1 for grape juice; 0.06–0.08 ng mL−1 for honey), good repeatability (intra-day/inter-day precision are 1.86–5.37%/1.82–7.79%, respectively) and only 5 mg of adsorbent per cartridge was established by optimizing the SPE process combined with high performance liquid chromatography with ultraviolet-visible detector (HPLC-UV). Meanwhile, selectivity study and comparative experiments with the commercial C18 adsorbent showed that the MOF@COF adsorbent exhibited satisfactory extraction efficiency for flavonoids due to multiple interactions such as hydrogen bonding, hydrophobic, and π-π interactions. Finally, the good recoveries in grape juice (84.5–102.5%) and honey (87.5–104.6%) samples further validated the applicability of the proposed method in complex samples. [ABSTRACT FROM AUTHOR]

• The electrospinning method was used for nanofiber coated stainless steel mesh. • The PVA@UiO-66 nanofiber coated stainless steel mesh was used as sorbent. • PVA@UiO-66 coating displayed good extraction ability for phthalate esters. • PVA nanofiber coating reinforced with UiO-66 has high extraction efficiency. Herein, an electrospun composite polyvinyl alcohol/zirconium-based metal-organic frameworks (PVA@UiO-66) nanofiber coating was prepared on the surface of stainless steel mesh (SSM) and then utilized as novel sorbent for the extraction of phthalate esters (PEs) in milk and water samples. Gas chromatography equipped with a flame ionization detector (GC–FID) was used for the quantitative determination of extracted analytes. The SSM coated with PVA@UiO-66 was used in a polypropylene syringe to fabricate the solid-phase extraction (SPE) device. The PVA@UiO-66 nanofiber coating was confirmed using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy analysis (FT–IR), and field emission scanning electron microscopy (FESEM). The effective parameters of the extraction efficiency including volume and type of desorption solvent, sample volume, ionic strength, pH, extraction flow rate, and desorption flow rate were optimized. At the optimal extraction conditions, the calibration plots for phthalate esters were linear within the range of 0.05–100 ng mL−1 and, low detection limits (0.015–0.06 ng mL−1). Finally, this semi-automated SPE was used for the extraction and detection of phthalate esters (PEs) in milk and various environmental real water samples. The results showed good precision with acceptable and satisfactory extraction recovery values ranging from 89.5 to 99.2% and relative standard deviations (RSDs%) ranging from 4.5 to 6.9%. [ABSTRACT FROM AUTHOR]

• A novel carboxyl functionalized porous polymer (PDA-DPBP) was synthesized. • PDA-DPBP showed excellent adsorption capacity for endocrine disrupting chemicals. • A sensitive method for detection of EDCs in water, juice and milk was established. • The adsorption can be ascribed to hydrogen bonding, pore filling and π-π interaction. Endocrine disrupting chemicals (EDCs) pose a serious threat to human health even at extremely low concentration. Three carboxyl functionalized porous polymers (PDA-DPBP, PTCDA-DPBP and ODPA-DPBP) were synthesized for the first time and employed as solid-phase extraction sorbent to enrich phenolic EDCs at trace level. Compared with PTCDA-DPBP, ODPA-DPBP and corresponding carboxyl-free counterpart (PC-DPBP), PDA-DPBP delivered superior enrichment efficiency for the phenolic EDCs, which can be ascribed to the strong hydrogen bonding, pore filling, hydrophobic interaction and π-π interaction between PDA-DPBP and phenolic EDCs. Coupled with high performance liquid chromatography, phenolic EDC residues in bottled water, juice and milk samples were enriched and determined. At the optimum conditions, the PDA-DPBP based method provided a good linear response in the range of 0.04–100ng mL−1 for bottled water, 0.07–100ng mL−1 for juice and 0.15–500ng mL−1 for milk samples. The detection limits (S/ N =3) were 0.01–0.04, 0.02–0.06 and 0.05–0.10ng mL−1 for bottled water, juice and milk, respectively. The method recoveries were in the range from 81.6% to 116%, with RSDs ≤ 7.7%. This work provides an attractive and reliable alternative method for sensitive determination of phenolic EDCs. [ABSTRACT FROM AUTHOR]

• An efficient enrichment method for polyphenol (PP) in grain vinegar was established. • Strata-XA column is more suitable for purification than other extraction columns. • Sixteen PPs with antioxidant activity in vinegar were identified using SPE-GC–MS. • The purified extract showed higher anti-saccharification and antioxidant activity. The extraction, purification, qualification, and quantification of polyphenols (PPs) in vinegar are challenging owing to the complex matrix of vinegar and the specific physicochemical and structural properties of PPs. This study aimed to develop a simple, efficient, low-cost method for enriching and purifying vinegar PPs. The enrichment and purification effects of five solid phase extraction (SPE) columns and five macroporous adsorption resins (MARs) for PPs were compared. The results show that SPE columns were more effective in purifying vinegar PPs than MARs. Among them, the Strata-XA column showed a higher recovery (78.469 ± 0.949%), yield (80.808 ± 2.146%), and purity (86.629 ± 0.978%) than other columns. In total, 48 PPs were identified and quantified using SPE and gas chromatography-mass spectrometry from the SPE column extracts; phenolic acids, such as 4-hydroxyphenyllactic acid, vanillic acid, 4-hydroxycinnamic acid, 4-hydroxybenzoic acid, protocatechuic acid, and 3-(4-Hydroxy-3-methoxyphenyl) propionic acid, occupy a major position in SAV. Furthermore, considering the potential applications of PPs, the concentrates were characterized based on their bioactive properties. They exhibited high total PP, flavonoid, and melanoidin contents and excellent anti-glycosylation and antioxidant activities. These results indicate that the established methodology is a high-efficiency, rapid-extraction, and environment-friendly method for separating and purifying PPs, with broad application prospects in the food, chemical, and cosmetic industries. [ABSTRACT FROM AUTHOR]

• A new heteroatom-rich HCP (named HCP-TPP-BCMBP) was successfully synthesized. • It was used as the adsorbent for the effective SPE of some nitroimidazoles (NDZs). • HCP-TPP-BCMBP showed a good adsorption capability for the antibiotics. • The method was suitable for NDZs determination in real complex-matrix samples. In this work, a series of 5,10,15,20-tetraphenylporphyrin (TPP)-based hyper crosslinked polymers were prepared by Friedel-Crafts reaction. Among them, the HCP-TPP-BCMBP, which was prepared by using TPP as the monomer and with 4,4′-Bis(chloromethyl)-1,1′-biphenyl (BCMBP) as the cross-linking agent, had the best adsorption capability for the enrichment of the nitroimidazoles of dimetridazole, ronidazole, secnidazole, metronidazole, and ornidazole. Then, a solid-phase extraction (SPE) method with the HCP-TPP-BCMBP as adsorbent coupled with HPLC-UV detection for the determination of nitroimidazole residues in honey, environmental water, and chicken breast samples was established. The influence of the main factors that affect the SPE, i.e., sample solution volume, sample loading rate, sample pH, and eluent and its volume, were studied. Under the optimal conditions, the limits of detection (S/N = 3) for the nitroimidazoles were measured to be in the range of 0.02-0.04 ng mL−1, 0.4-1.0 ng g−1 and 0.5-0.7 ng g−1 for environmental water, honey, and chicken breast samples, with the determination coefficients being in the range of 0.9933-0.9998. The analytes recoveries by the method in fortified samples fell in the range from 91.1% to 102.7% for environmental water, from 83.2% to 105.0% for honey, and from 85.9% to 103.0% for chicken breast samples, and the relative standard deviations for the determination were less than 10%. It shows that the HCP-TPP-BCMBP has a strong adsorption capability for some polar compounds. [ABSTRACT FROM AUTHOR]

Highlights • Efficient SPE methods for extraction of six MCs from biofluids were developed. • MC extraction from plasma and serum was improved using ZnSO 4 and 0.1% formic acid. • ≤ 1 μg/L concentrations of MCs were quantified using SPE and LC-ESI-MS. • MC-LR was quantified in urine and plasma of mice that had been administered MC-LR. • Increased MC-LR dosage led to larger amounts of MC-LR in mouse urine and plasma. Abstract The protocols for solid-phase extraction (SPE) of six microcystins (MCs; MC-LR, MC-RR, MC-LA, MC-LF, MC-LW, and MC-YR) from mouse urine, mouse plasma, and human serum are reported. The quantification of those MCs in biofluids was achieved using HPLC-orbitrap-MS in selected-ion monitoring (SIM) mode, and MCs in urine samples were also quantified by ultra-HPLC-triple quadrupole-tandem mass spectrometry (UHPLC-QqQ-MS/MS) in multiple reaction monitoring (MRM) mode. Under optimal conditions, the extraction recoveries of MCs from samples spiked at two different concentrations (1 μg/L and 10 μg/L) ranged from 90.4% to 104.3% with relative standard deviations (RSDs) ≤ 4.7% for mouse urine, 90.4–106.9% with RSDs ≤ 6.3% for mouse plasma, and 90.0–104.8% with RSDs ≤ 5.0% for human serum. Matrix-matched internal standard calibration curves were linear with R2 ≥ 0.9950 for MC-LR, MC-RR and MC-YR, and R2 ≥ 0.9883 for MC-LA, MC-LF, and MC-LW. The limits of quantification (LOQs) in spiked urine samples were ∼0.13 μg/L for MC-LR, MC-RR, and MC-YR, and ∼0.50 μg/L for MC-LA, MC-LF, and MC-LW, while the LOQs in spiked plasma and serum were ∼0.25 μg/L for MC-LR, MC-RR, and MC-YR, and ∼1.00 μg/L for MC-LA, MC-LF, and MC-LW. The developed methods were applied in a proof-of-concept study to quantify urinary and blood concentrations of MC-LR after oral administration to mice. The urine of mice administered 50 μg of MC-LR per kg bodyweight contained on average 1.30 μg/L of MC-LR (n = 8), while mice administered 100 μg of MC-LR per kg bodyweight had average MC-LR concentration of 2.82 μg/L (n = 8). MC-LR was also quantified in the plasma of the same mice. The results showed that increased MC-LR dosage led to larger urinary and plasma MC-LR concentrations and the developed methods were effective for the quantification of MCs in mouse biofluids. [ABSTRACT FROM AUTHOR]

Highlights • A guanidyl functionalized graphene oxide-grafted silica was designed for the extraction of acidic compounds. • Experiment parameters were optimized using the response surface methodology. • The adsorption mechanism was investigated and evaluated. • The proposed method is suitable for the determination of acidic herbicides. Abstract A highly selective and efficient extraction material was synthesized through the functionalization of guanidyl onto the graphene oxide-grafted silica via a simple chemical modification, which was designed and proposed to improve the enrichment capacity for acidic herbicides. The extraction material was confirmed by scanning electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectrometry, thermal gravimetric analyzer and zeta potential analysis. Theoretical adsorption energies, static- and dynamic-state binding experiments, and comparative experiments with various adsorbents were investigated to elucidate the adsorption mechanism. The introduction of guanidyl endowed the sorbent with stronger Lewis base property and electron-donating ability, hence, excellent extraction recoveries for acidic herbicides could be obtained. Besides, electrostatic and π-π interactions were considered as two major driving impetuses in the adsorption process. Single-factor experiment and response surface methodology were utilized for the optimization of extraction and desorption conditions. Under the optimized conditions, the wide linearities were obtained with correlation coefficients ranging from 0.9904 to 0.9980, and the method detection limits were in the range of 0.5–2 μg L−1. The relative standard deviation values of the recoveries of five different extractions were 3.0–7.1%. Coupled with high performance liquid chromatography, the as-proposed method was successfully applied to detect five acidic herbicides in Lycium barbarum (Goji). It turned out that the proposed method provided a promising perspective for the selective extraction and determination of polar acidic compounds in complex samples. [ABSTRACT FROM AUTHOR]

This study presents a new multi-residue analytical method for the simultaneous determination of 38 psychoactive drugs (including benzodiazepines, antidepressants and drugs of abuse) and related metabolites in raw wastewater. Potential analyte losses during sample filtration and stability in wastewater were evaluated. Analyte losses, especially for 12 compounds, were observed during filtration, indicating a strong sorption onto the filter material. In order to overcome this effect, filtered water samples were combined with methanolic washes of the corresponding filters and the resulting solutions were solid-phase extracted on mixed-mode (reverse-phase plus cation-exchange) sorbents. Extracts were analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry. Quantification was performed by the internal standard method with isotopic labeled analogs. Recovery percentages varied between 65% and 137%; method quantification limits ranged between 0.2 and 22 ng/L in ultrapure water and between 0.3 and 30 ng/L in wastewater for all the analytes but three (for which they were ∼60–80 ng/L). The analysis of 24 h-composite samples collected during one week in the city of Santiago de Compostela demonstrated the ubiquity of 31 analytes, which were positively quantified in all samples. The highest concentrations were found for some of the antidepressants, with mean and maximum levels exceeding, in some cases, the levels previously reported in literature. This fact could be related to the additional washing step of the filters using methanol, which allowed to desorb retained analytes highlighting the importance of this step during the sample preparation protocol. [ABSTRACT FROM AUTHOR]

Two novel periodic mesoporous organosilica materials were synthesized with a neutral phenylene-bridged ligand, 1,4-bis(trimethoxysilylethyl)benzene, one of them using tetraethyl orthosilicate as additional silica source (PMO-TMSEB-1 and PMO-TMSEB-2). A third material was also synthesized with 1,4-bis(triethoxysilyl)benzene ligand (PMO-TESB-1) which use has scarcely been reported. The three materials were evaluated as solid-phase extraction (SPE) sorbents for the off-line extraction of a mixture of seven drugs of different nature (duloxetine, terbutaline, econazole, propranolol, verapamil, metoprolol, and betaxolol) from water samples. Subsequent simultaneous enantiomeric analysis by CE, using sulfated-β-cyclodextrin (2% w/v) dissolved in a 25 mM phosphate buffer (pH 3.0) and a voltage of −20 kV (negative polarity) was carried out. Enantiomeric resolutions ranging from 2.4 to 8.5 were obtained in an analysis time of 16 min. After optimization of SPE parameters, it was shown that using just 100 mg of PMO-TESB-1 as sorbent, a preconcentration factor of 400 with 200 mL solution was achieved, allowing recoveries between 80.5 and 103.1% (except for terbutaline), with good repeatability (% RSD = 2–8 %, n = 5). Analytical characteristics of the method were evaluated in terms of precision, linearity and accuracy with method quantitation limits between 5.6 and 21.9 μg/L. The developed method was applied to the analysis of spiked wastewater samples collected in different treatment plants, with recoveries between 73.9 and 102.9% except for econazole with recovery values ranging between 58.5 and 72.4%. [ABSTRACT FROM AUTHOR]

Two novel materials based on periodic mesoporous organosilica (PMO) with cationic amine-bridged ligands, (styrylmethyl)bis(triethoxysilylpropyl)ammonium chloride (PMO-STPA) and bis(3-triethoxysilylpropyl)amine (PMO-TEPA), were synthesized in this work to obtain materials with reverse-phase/strong anionic exchange mixed-mode or strong anionic exchange retention mechanism, respectively. The resulting materials were comprehensively characterized and showed functionalization with cationic amine-bridged ligands, and values of surface areas characteristic of mesoporous materials (higher than 100 m 2 /g). These materials were evaluated for the off-line solid-phase extraction (SPE) of a mixture of six phenoxy acid herbicides (fenoprop, mecoprop, dichlorprop, 2-(4-chlorophenoxy)propionic acid (4-CPPA), 2-(3-chlorophenoxy)propionic acid (3-CPPA), 2-phenoxypropionic acid (2-PPA)) from water samples previous to their analysis by CE with diode-array detection using a dual chiral selector system (20 mM of heptakis(2,3,6-tri-O-methyl)-β-CD (TM-β-CD) and 7 mM of (2-hydroxypropyl)-β-CD (HP-β-CD) dissolved in 50 mM phosphate buffer, pH 7.0) which enabled the simultaneous enantiomeric separation of the six phenoxy acid herbicides in 11 min. SPE parameters were optimized and recoveries obtained for PMO-STPA and PMO-TEPA sorbents were compared. Under the optimized conditions, it was demonstrated that using 100 mg of PMO-STPA sorbent, a maximum preconcentration factor (PF) of 1500 was achieved with 750 mL of standard solution, allowing recoveries between 75.5 and 112.2%, with good repeatability (RSD = 1.9–8.7%, n = 6). Analytical characteristics of the method were evaluated in terms of precision, linearity and accuracy with method quantitation limits (MQL) between 0.4 and 14.3 μg/L. The developed method was applied to the analysis of river samples and effluents from wastewater treatment plants, with recoveries ranging from 78.3 to 107.5%. [ABSTRACT FROM AUTHOR]

A novel sorbent material, gold-polypyrrole (Au-PPy) nanocomposite-coated silica, is described for the efficient solid-phase extraction (SPE) of six common microcystins (MCs) well below the recommended United States EPA and World Health Organization (WHO) guidelines. With the optimized SPE protocol, samples spiked with MCs were determined at ng/L concentrations by liquid chromatography-mass spectrometry (LC–MS) in different aqueous sample matrices, including HPLC-grade, tap, and lake water. The average recoveries for all MCs tested in the three water matrices ranged from 94.1–103.2% with relative standard deviations (RSDs) of 1.6–5.4%, which indicated excellent extraction efficiency and reproducibility. Limits of detection (LODs) and limits of quantification (LOQs) for all MCs in both tap and lake water samples were determined to be ≤1.5 ng/L and 5.0 ng/L, respectively. The Au-PPy nanocomposite-coated sorbent material was reusable for at least three independent MC extractions with a single SPE cartridge in the concentration range of 10–500 ng/L. Importantly, off-column selective separation at the sample preparation and preconcentration stage between more hydrophilic and more hydrophobic MCs was achieved by sequential elution through changes in the solvent composition and SPE bed size. Therefore, the Au-PPy nanocomposite-coated silica sorbent is a promising new material for the quantification of MC variants in water samples. [ABSTRACT FROM AUTHOR]

Pristine humic acids (HAs) were thermally condensed onto silica microparticles by a one-pot, inexpensive and green preparation route obtaining a mixed-mode sorbent (HA-C@silica) with good sorption affinity for glucocorticoids (GCs). The carbon-based material, characterized by various techniques, was indeed applied as the sorbent for fixed-bed solid-phase extraction of eight GCs from river water and wastewater treatment plant effluent, spiked at different concentration levels in the range 1–400 ng L −1 . After sample extraction, the target analytes were simultaneously and quantitatively eluted in a single fraction of methanol, achieving enrichment factor 4000 and 1000 in river water and wastewater effluent, respectively. Full recovery for all compounds, was gained in the real matrices studied (80–125% in river water, 79–126% in wastewater effluent), with inter-day precision showing relative standard deviations (RSD) below 15% and 18% ( n  = 3), for river and wastewater effluent, correspondingly. The high enrichment factors coupled with high-performance liquid chromatography tandem mass spectrometry quantification (MRM mode) provided method quantification limits of 0.009–0.48 ng L −1 in river water and 0.06–3 ng L −1 in wastewater effluent and, at the same time, secure identification of the selected drugs. As also evidenced by comparison with literature, HA-C@silica proved to be a valid alternative to the current commercial sorbents, in terms of extraction capability, enrichment factor, ease of preparation and cost. The batch-to-batch reproducibility was assessed by recovery tests on three independently prepared HA-C@silica powders (RSD lower than 7%). [ABSTRACT FROM AUTHOR]

A hypercrosslinked triphenylamine polymer (HCTPA) was prepared through a simple one-step Friedel-Crafts alkylation reaction. The HCTPA had an extended π-conjugated system, large specific surface area and high micropore volume. In order to evaluate its extraction performance, the HCTPA was used as the adsorbent for the solid-phase extraction of the phenylurea herbicides (monuron, chlortoluron, isoproturon, monolinuron and buturon) from watermelon, tomato and cucumber samples. The main parameters that could affect the extraction efficiency including the sample volume, sample solution pH, sample solution loading rate and desorption conditions were investigated and optimized. Under the optimized conditions, the HCTPA showed a good extraction performance for the target analytes. The linear range for the quantification of the analytes was in the range of 0.4–160.0 ng g −1 with the correlation coefficients of 0.9996–0.9999. The limits of detection (S/N = 3) of the analytes by the method ranged from 0.06 to 0.12 ng g −1 for watermelon and tomato, and 0.06–0.15 ng g −1 for cucumber samples. The recoveries of the analytes for the method were between 83.1% and 112.5% with the relative standard deviations below 5.5%. These results indicate that the HCTPA can be used for the enrichment of phenylurea herbicides from complex matrix samples like watermelon, tomato and cucumbers. [ABSTRACT FROM AUTHOR]

A frequently studied environmental contaminant is the active substance diclofenac, which is removed insufficiently in sewage treatment plants. Since its inclusion in the watch list of the EU Water Framework Directive, the concentrations in surface waters will be determined throughout Europe. For this, still, more precise analytical methods are needed. As a reference, HPLC-MS is frequently employed. One of the major metabolites is 4'-hydroxydiclofenac (4'-OH-DCF). Also, diclofenac lactam is important for assessing degradation and transformation. Aceclofenac (ACF), the glycolic acid ester of diclofenac is used as a drug, too, and could potentially be cleaved to yield diclofenac again. In various sewage treatment plant influent samples, diclofenac, 4'-OH-DCF, DCF lactam and ACF could be determined with detection limits of 3 μg/L, 0.2 μg/L, 0.17 μg/L and 10 ng/L, respectively. [ABSTRACT FROM AUTHOR]

This paper demonstrated the development and validation of an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) method for simultaneous determination of five glycopeptide antibiotics in food and biological samples. The target glycopeptide antibiotics were isolated from the samples by solvent extraction, and the extracts were cleaned with a tandem solid-phase extraction step using mixed strong cation exchange and hydrophilic/lipophilic balance cartridges. Subsequently, the analytes were eluted with different solvents, and then quantified by UHPLC–MS/MS in the positive ionization mode with multiple reaction monitoring. Under optimal conditions, good linear correlations were obtained for the five glycopeptide antibiotics in the concentration range of 1.0 μg/L to 20.0 μg/L, and with linear correlation coefficients >0.998. Employing this method, the target glycopeptide antibiotics in food and biological samples were identified with a recovery of 83.0–102%, and a low quantitation limit of 1.0 μg/kg in food and 2.0 μg/L in biological samples with low matrix effects. [ABSTRACT FROM AUTHOR]

A composite of multi-walled carbon nanotubes incorporated into a benzyl methacrylate- co -ethylene dimethacrylate porous monolith was prepared, characterized and used as solid phase adsorbent and as stationary phase for simultaneous extraction and separation of ten polycyclic aromatic hydrocarbons, followed by nano-liquid chromatography analysis. The extraction and chromatographic parameters were optimized with regard to the extraction efficiency and the quality of chromatographic analytes separation. Under the optimized conditions, all PAHs were separated in 13 min with suitable resolution values (Rs = 1.74–3.98). Addition of a small amount of carbon nanotubes (0.1% with respect to monomers) to the polymerization mixture increased the efficiency for the separation column to over 41,700 plates m −1 for chrysene at flow rate of 0.5 μL min −1 . The method showed a wide linear range (1–500 μg L −1 with R 2 more than 0.9938), acceptable extraction repeatability (RSDs < 6.4%, n = 3) and reproducibility (RSDs < 12.6%, five parallel-made solid phase extraction cartridges) and satisfactory detection limits (0.02–0.22 μg L −1 ). Finally, the proposed method was successfully applied to the detection of polycyclic aromatic hydrocarbons in environmental water samples. After a simple extraction procedure with preconcentration factor equal to 100, the average recovery values in ultra-pure, tap and sea water samples were found to be in the range 81.3–95.4% with %RSD less than 6.4. Again, the presence of carbon nanotubes (0.3% relatively to monomers) in native polymer enhanced the extraction performance for the solid phase adsorbent up to 78.4%. The application of the monoliths modified with CNTs in extraction and nano-scale liquid chromatography for analysis of environmental samples offered several advantages; it demonstrated an acceptable precision, low detection limits, good reproducibility, satisfying recoveries and wide dynamic linear ranges. [ABSTRACT FROM AUTHOR]

A novel magnetic solid–phase extraction approach was proposed for extraction of potential residues of tetracyclines (TCs) in tap and river water samples, based on Fe 3 O 4 @SiO 2 @FeO magnetic nanocomposite. Characterized results showed that the received Fe 3 O 4 @SiO 2 @FeO had distinguished magnetism and core–shell structure. Modified FeO nanoparticles with an ∼5 nm size distribution were homogeneously dispersed on the surface of the silica shell. Owing to the strong surface affinity of Fe (II) toward TCs, the magnetic nanocomposite could be applied to efficiently extract three TCs antibiotics, namely, oxytetracycline, tetracycline and chlortetracycline from water samples. Several factors, such as sorbent amount, pH condition, adsorption and desorption time, desorption solvent, selectivity and sample volume, influencing the extraction performance of TCs were investigated and optimized. The developed method showed excellent linearity (R > 0.9992) in the range of 0.133–333 μg L −1 , under optimized conditions. The limits of detection were between 0.027 and 0.107 μg L −1 for oxytetracycline, tetracycline and chlortetracycline, respectively. The feasibility of this method was evaluated by analysis of tap and river water samples. The recoveries at the spiked concentration levels ranged from 91.0% to 104.6% with favorable reproducibility (RSD < 4%). [ABSTRACT FROM AUTHOR]

In the present study, the preparation of the magnetic phosphodiesterase-5 linked Fe 3 O 4 @ SiO 2 nanoparticles was successfully achieved by amide reaction and the magnetic phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles were evaluated as a new adsorbent for magnetic dispersive solid-phase extraction of ligands from medicinal plant samples before the analysis by UHPLC-Q-TOF/MS. The prepared phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, vibration sample magnetometer and potential laser particle size analyzer. The effects of EDC concentration, incubation time and bead-protein ratio on the amount of immobilized protein were studied. The main experimental parameters affect extraction efficiency of ligands, such as wash times, wash solvents, incubation pH, ion strength and incubation temperature, were investigated and optimized by using echinacoside as a model compound. The absolute recovery of echinacoside was ranged from 98.36%–102.16% in Cistanche tubulosa sample under the optimal extraction conditions. Good linearity was observed in the investigated concentration range of 0.006 mg   mL −1 –0.97 mg   mL −1 (R 2  = 0.9999). The limit of detection was 0.002 mg   mL −1 . The RSDs of within-day and between-day precision were less than 2.3%. Due to the excellent magnetic behavior of Fe 3 O 4 @SiO 2 nanoparticles, the proposed method was shown to be simple and rapid. Remarkably, the magnetic phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles could be recycled for ten times with loss of 10% activity. [ABSTRACT FROM AUTHOR]

The influence of natural organic matter (NOM) on the solid-phase extraction (SPE) efficiency was investigated for legacy and emerging flame retardants (FRs; n = 26) in surface water. Three different groups of FRs were analyzed: polybrominated diphenyl ethers (PBDEs), halogenated flame retardants (HFRs), and organophosphorus flame retardants (OPFRs). In addition, five sorbents (Amberlite XAD-2, Amberlite IRA-743, Oasis HLB, Chromabond HR-P, and Chromabond HR-X) were evaluated for the extraction of FRs ( n = 33) in water, of which Oasis HLB eluted with dichloromethane and acetone: n -hexane (1:1, v/v) provided the highest overall recoveries. In subsequent NOM experiments, where FRs were extracted from water containing different NOM concentrations, both increased and decreased extraction efficiency with increasing NOM level were observed. Physicochemical and semi-empirical quantum chemistry properties were calculated for the FRs and used for analyzing relations between FRs. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that the FRs separated into four different groups based on their properties. The FRs within each group responded similarly to increasing NOM, while differences in behavior were observed between the groups. This suggests that the structural properties of micropollutants highly influence NOM-FR interaction mechanisms. For instance, at high NOM levels, recoveries decreased substantially for FRs containing a moiety that can form strong hydrogen bonds (such as the double-bonded oxygen in e.g., OPFRs). Many of the compounds showed maximum extraction efficiency at higher levels of NOM. This suggests that binding of NOM to the sorbent and subsequent interaction between sorbent-bound NOM and FRs is an important mechanism for extraction of micropollutants from surface waters. [ABSTRACT FROM AUTHOR]

Synthetic cathinones have become popular in recent years, which would explain why their determination in influent sewage samples has already been documented. In the present study a method based on solid-phase extraction followed by liquid chromatography and high resolution mass spectrometry is developed, validated and applied to determine twelve cathinones and one of their metabolites in different environmental samples including influent and effluent sewage and river water. Two cation-exchange sorbents (Oasis MCX and Oasis WCX) were compared, with better results achieved with Oasis WCX in terms of apparent recoveries (70–100%) and matrix effects (lower than −34%). The method was validated with effluent sewage samples providing suitable figures of merit, with method quantification limits ranging from 1 ng/L to 5 ng/L and method detection limits from 0.1 ng/L to 0.5 ng/L for all the compounds. Of the different cathinones studied, three, namely methylone, mephedrone metabolite and methylenedioxypyrovalerone, were quantified at concentration levels of low ng/L in each of the different samples analysed, while a number of the other cathinones were also detected in some of the samples. [ABSTRACT FROM AUTHOR]

• Four amine-modified amphiphilic resins were prepared. • The resins possessed large specific surface area and high ion exchange capacity. • WAAM (NVP) maintained positive Zeta potential with change of pH. • A method of SPE/LC-MS/MS was developed. • The method demonstrated good accuracy and sensitivity. Herein, four amine-modified amphiphilic resins were synthesized and utilized as solid-phase extraction (SPE) materials to enrich pharmaceuticals and personal care products (PPCPs) from environmental water. The obtained materials (Strong anion-exchange amphiphilic materials, SAAMs; Weak anion-exchange amphiphilic materials, WAAMs) possessed large specific surface area (473–626 m2/g), high ion exchange capacity (0.89–1.97 mmol/g), and small contact angle (74.41–79.74°), indicating good hydrophilicity. The main factors affecting the efficiency of the extraction process were studied, including column volume, column flow rate, sample salinity and sample pH. Notably, the trend observed in absolute recovery was significantly correlated with the Zeta potential of the employed adsorbents. Furthermore, based on the obtained materials, a method of SPE coupled with ultra-performance liquid chromatography and tandem mass spectrometry (SPE/LC-MS/MS) was developed, and then utilized to determine PPCPs in the samples collected from the Yangtze River Delta. The Method detection limit (MDL) and Method quantification limit (MQL) ranged from 0.05 to 0.60 ng/L and 0.17 to 2.00 ng/L, respectively, with a relative standard deviation (RSD) below 6.3%, demonstrating good accuracy and sensitivity. As evidenced by comparison with previous literature, the developed method exhibited satisfactory performance, showing great potential for further commercial application in the extraction of trace PPCPs from environmental water samples. [ABSTRACT FROM AUTHOR]

• Spin column extraction (SCE) for OPPs. • A polydopamine@polymer monolith in spin column was prepared. • The monolith exhibited enhanced adsorption affinity towards OPPs. • Excellent permeability, stability and reusability of the monolith. • SCE was successfully applied for fast and simple analysis of OPPs in urine. The determination of organophosphorus pesticides in urine is useful for evaluating human exposure. In this study, a simple micro-solid-phase extraction method based on a polydopamine-modified monolithic spin column combined with liquid chromatography–mass spectrometry (LC-MS) was developed for the determination of six organophosphorus pesticides (dimethoate , dichlorvos, carbofuran, methidathion, phosalone, and chlorpyrifos) in urine samples. A methacrylate polymer monolithic support was prepared in situ in the spin column, and dopamine solution was repeatedly passed through the monolith matrix via centrifugation to generate a polydopamine layer in the polymeric network. All extraction steps were performed via centrifugation. The monolith exhibited good permeability, which enabled high-flow-rate sample loading and significantly reduced the sample pre-treatment time. The addition of polydopamine significantly improved the extraction efficiency of the monolithic spin column owing to the catechol and amine groups in dopamine, which can enhance hydrogen bonding and π–π stacking. Factors affecting the extraction, including the solution pH, centrifugation speed, and desorption solvent, were investigated to determine the optimal extraction conditions. Under the optimal conditions, the OPP detection limits were 0.02–1.32 µg/L. The relative standard deviations of the single column (n = 5) and column-to-column (n = 3) precision for the extraction method were <11%. The monolithic spin column exhibited high stability and could be used for more than 40 extraction cycles. The recoveries for spiked urine samples were 72.1–109.3% (RSDs: 1.6–7.9%). The developed method was successfully applied to the simple and rapid analysis of organophosphorus pesticides in urine samples. [ABSTRACT FROM AUTHOR]

Phosphatidylethanol (PEth) is an interesting biomarker finding increased use for detecting long term alcohol abuse with high specificity and sensitivity. Prior to detection, sample preparation is an unavoidable step in the work-flow of PEth analysis and new protocols may facilitate it. Solid-phase extraction (SPE) is a versatile sample preparation method widely spread in biomedical laboratories due to its simplicity of use and the possibility of automation. In this work, SPE was used for the first time to directly extract PEth from spiked human plasma and spiked human blood. A library of polymeric SPE materials with different surface functionalities was screened for PEth extraction in order to identify the surface characteristics that control PEth retention and recovery. The plasma samples were diluted 1:10 (v/v) in water and spiked at different concentrations ranging from 0.3 to 5 μM. The library of SPE materials was then evaluated using the proposed SPE method and detection was done by LC–MS/MS. One SPE material efficiently retained and recovered PEth from spiked human plasma. With this insight, four new SPE materials were formulated and synthesized based on the surface characteristics of the best SPE material found in the first screening. These new materials were tested with spiked human blood, to better mimic a real clinical sample. All the newly synthetized materials outperformed the pre-existing commercially available materials. Recovery values for the new SPE materials were found between 29.5% and 48.6% for the extraction of PEth in spiked blood. A material based on quaternized 1-vinylimidazole with a poly(trimethylolpropane trimethacrylate) backbone was found suitable for PEth extraction in spiked blood showing the highest analyte recovery in this experiment, 48.6% ± 6.4%. [ABSTRACT FROM AUTHOR]

Monolithic silica in MonoSpin for solid-phase extraction of drugs from whole blood samples was developed to facilitate high-throughput analysis. Monolithic silica of various pore sizes and octadecyl contents were synthesized, and their effects on recovery rates were evaluated. The silica monolith M18-200 (20 μm through-pore size, 10.4 nm mesopore size, and 17.3% carbon content) achieved the best recovery of the target analytes in whole blood samples. The extraction proceeded with centrifugal force at 1000 rpm for 2 min, and the eluate was directly injected into the liquid chromatography–mass spectrometry system without any tedious steps such as evaporation of extraction solvents. Under the optimized condition, low detection limits of 0.5–2.0 ng mL −1 and calibration ranges up to 1000 ng mL −1 were obtained. The recoveries of the target drugs in the whole blood were 76–108% with relative standard deviation of less than 14.3%. These results indicate that the developed method based on monolithic silica is convenient, highly efficient, and applicable for detecting drugs in whole blood samples. [ABSTRACT FROM AUTHOR]

A new reliable method for the determination 3-alkyl-2-methoxypyrazines (MPs) in wine samples based on the sequential combination of solid-phase extraction (SPE), dispersive liquid–liquid microextraction (DLLME) and gas chromatography (GC) quadrupole time-of-flight accurate tandem mass spectrometry (QTOF-MS/MS) is presented. Primary extraction of target analytes was carried out by using a reversed-phase Oasis HLB (200 mg) SPE cartridge combined with acetonitrile as elution solvent. Afterwards, the SPE extract was submitted to DLLME concentration using 0.06 mL carbon tetrachloride (CCl 4 ) as extractant. Under final working conditions, sample concentration factors above 379 times and limits of quantification (LOQs) between 0.3 and 2.1 ng L −1 were achieved. Moreover, the overall extraction efficiency of the method was unaffected by the particular characteristics of each wine; thus, accurate results (relative recoveries from 84 to 108% for samples spiked at concentrations from 5 to 25 ng L −1 ) were obtained using matrix-matched standards, without using standard additions over every sample. Highly selective chromatographic records were achieved considering a mass window of 5 mDa, centered in the quantification product ion corresponding to each compound. Twelve commercial wines, elaborated with grapes from different varieties and geographical origins, were processed with the optimized method. The 2-isobutyl-3-methoxypyrazine (IBMP) was determined at levels above the LOQs of the method in half of the samples. [ABSTRACT FROM AUTHOR]

This work reports the development of a multi-residue method for the identification and quantification of 82 veterinary drugs belonging to different chemical classes in swine waste lagoon. The proposed method applies a solid-phase extraction procedure with Oasis PRiME HLB cartridges that combines isolation of the compounds and sample clean-up in a single step. Analysis is performed by ultra-high performance liquid chromatography-tandem mass spectrometry, in one single injection with a chromatographic run time of only 9.5 min. Linearity was studied in the range between 1 and 500 μg kg −1 using standards prepared both in pure solvent and in the presence of matrix, showing coefficients of determination higher than 0.99 for all the analytes except for cefapirin in matrix. The average recoveries were in the range of 60–110% for most of the compounds tested with inter-day relative standard deviations below 17%. More than 97% of the investigated compounds had less or equal to a 5 μg kg −1 quantitation limit in the studied matrix. Finally, the method was used with success to detect and quantify veterinary drugs residues in real samples with sulfonamides, quinolones, and tetracyclines being the most frequently determined compound groups. [ABSTRACT FROM AUTHOR]

A facile approach for preparation of hydrophilic polysaccharide-functionalized macroporous adsorption resin (MAR) was presented. Polydisperse MAR with approximately 250 μm in diameter was synthesized via suspension polymerization and then modified with polysaccharides, sodium hyaluronate (HA) and chitosan (CS), through layer-by-layer (LbL) self-assembly process. The preparation method was facile, low cost and easy to expand production from tens of grams to one kilogram. The resulting MAR@(HA/CS) 20 possesses highly hydrophilic property and rapid adsorption behavior. The specificity and efficiency of MAR@(HA/CS) 20 to glycopeptide was demonstrated by trapping N-linked glycopeptide from tryptic digests of human immunoglobulin G (IgG) and horseradish peroxidase (HRP) with a homemade solid-phase extraction (SPE) column. The detection sensitivity for glycopeptide determined by MALDI-TOF MS was as low as 5 fmol for standard tryptic digest of human IgG. The enrichment recoveries were higher than 73%. Furthermore, in the analysis of real biological sample, 745 unique N-glycosylation sites in 1353 unique glycopeptides mapped to 379 N-glycosylated proteins were identified in three replicate analyses of protein sample extracted from mouse liver, showing the great potential of MAR@(HA/CS) 20 in the enrichment and identification of low-abundance N-linked glycopeptides in complicated biological samples. [ABSTRACT FROM AUTHOR]

We present for the first time the application of metal-organic framework (MOF) mixed-matrix disks (MMD) for the automated flow-through solid-phase extraction (SPE) of environmental pollutants. Zirconium terephthalate UiO-66 and UiO-66-NH 2 MOFs with different size (90, 200 and 300 nm) have been incorporated into mechanically stable polyvinylidene difluoride (PVDF) disks. The performance of the MOF-MMDs for automated SPE of seven substituted phenols prior to HPLC analysis has been evaluated using the sequential injection analysis technique. MOF-MMDs enabled the simultaneous extraction of phenols with the concomitant size exclusion of molecules of larger size. The best extraction performance was obtained using a MOF-MMD containing 90 nm UiO-66-NH 2 crystals. Using the selected MOF-MMD, detection limits ranging from 0.1 to 0.2 μg L −1 were obtained. Relative standard deviations ranged from 3.9 to 5.3% intra-day, and 4.7–5.7% inter-day. Membrane batch-to-batch reproducibility was from 5.2 to 6.4%. Three different groundwater samples were analyzed with the proposed method using MOF-MMDs, obtaining recoveries ranging from 90 to 98% for all tested analytes. [ABSTRACT FROM AUTHOR]

Novel multi-template molecularly imprinted polymers (mt-MIPs) with six phenolic compounds as the template, namely phenol, 4-chlorophenol (4-CP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,4-dichlorophenol (2,4-DCP), 2-chlorophenol (2-CP) and 2,6-dichlorophenol (2,6-DCP), were prepared by precipitation polymerization and used as the adsorbents of solid-phase extraction (SPE), and coupled with capillary electrophoresis (CE) for the simultaneous selective extraction, separation and determination of trace phenolic compounds in water samples. The resultant mt-MIPs exhibited uniform spherical morphology, large specific surface area and high thermal stability, and offered high selectivity towards the six template phenolic compounds. Various parameters affecting the molecularly imprinted SPE (MISPE) efficiency were investigated in detail, and excellent CE separation was realized within 7 min. Good linearity was obtained in the range of 1–200 μg L −1 for phenol and 4-CP, and 1–300 μg L −1 for 2,4,6-TCP, 2,4-DCP, 2-CP and 2,6-DCP. High sensitivity was attained with low limits of detection and quantification ranging from 0.17 to 0.31 μg L −1 and 0.57 to 1.03 μg L −1 , respectively. Satisfactory recoveries for spiked reservoir water, river water, tannery wastewater and tap water samples were achieved in the range of 82.13–105.63% with relative standard deviations within 1.68–6.96%. The developed MISPE-CE method proved practically feasible for simultaneous selective extraction/enrichment, separation and sensitive determination of multiple targets in complicated aqueous matrices. [ABSTRACT FROM AUTHOR]

For the first time, a reliable solid-phase extraction (SPE) procedure using iron (II, III) oxide (Fe 3 O 4 )/multi-walled carbon nanotube (MWCNT) composite as sorbents was proposed for purification and enrichment of zearalenone (ZEA) and four type A trichothecenes (T-2 toxin (T-2), HT-2 toxin (HT-2), neosolaniol (NEO) and diacetoxyscirpenol (DAS)) in Salviae miltiorrhiza Radix et Rhizoma (Danshen). The Fe 3 O 4 /MWCNT composite was synthesized by assembling Fe 3 O 4 with MWCNT by sonication through an “aggregation wrap” mechanism and several key parameters affecting the performance of SPE procedure such as the composition of sample loading solutions, washing and elution solvents were thoroughly investigated. After optimization, 2% acetonitrile aqueous solution as the loading solution, 5% methanol aqueous solution as the washing solution and acetone containing 0.5% formic acid as the elution solvent presented an excellent purification efficiency for the five targets in Danshen. Under the optimal sample pretreatment conditions followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry, satisfactory linearity (R 2 ≥ 0.991), high sensitivity (limit of quantification in the range of 1.20–4.80 μg kg −1 ), good recovery (73.7–91.9%) and acceptable precision (RSD, 2.1–13.3%) were obtained. The applicability of the validated method was further verified in real Salviae miltiorrhiza Radix et Rhizoma samples. [ABSTRACT FROM AUTHOR]