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• H-MON-PEI 1800 –2 is prepared via sacrificial template method and subsequent modification with PEI. • H-MON-PEI 1800 –2 based method offers wide linear range, low LODs and large EFs for PAs in juice samples. • Extraction mechanisms include π-π, hydrophobic, hydrogen bonding, and electrostatic interactions. 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-PEI 1800 –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-PEI 1800 –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-PEI 1800 –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. [ABSTRACT FROM AUTHOR]

• A HPLC-MS method for the analysis of NTTP with a quantitation limit of 0.5 ng/mL. • Selection of suitable stationary phases and mobile phases through screening. • Optimization of separation through chromatographic modeling and simulation. • High sensitivity with an inexpensive single quadrupole MS controlled by Empower CDS. • Easy method implementation at manufacturing labs for high-throughput analysis. Nitrosamine drug substance related impurities (NDSRIs) are often analyzed using high performance liquid chromatography (HPLC) with mass spectrometry (MS) detection. Due to high sensitivity requirements, high resolution MS or MS/MS is commonly used. However, it is difficult to implement this type of method for routine analysis at a supply site. Herein, we report a systematic approach to develop and validate a practical, robust, and user-friendly method for the analysis of NDSRIs using an inexpensive single quadrupole MS instrument such as QDa. We used 7-nitroso-3-(trifluoromethyl)-5,6,7,8-tetrahydro- [1,2,4] triazolo [4,3-a] pyrazine (NTTP) as an example to demonstrate the method development process. By optimizing the HPLC and MS parameters, we were able to develop a simple HPLC-MS method that provides the desired specificity and sensitivity for the analysis of NTTP and can be easily implemented in an analytical lab. The limit of quantitation is 0.5 ng/mL, corresponding to 0.1 ppm with respect to 5 mg/mL sitagliptin. The method has been successfully validated per ICH guidelines. [Display omitted] [ABSTRACT FROM AUTHOR]

• HEIWat system was more suitable for large-polar compounds while P' decreases. • The selected solvent systems could be divided into group III and IV. • Proportion and type of solvents had different effects in different CCC systems. Solvent system selection based on polarity is a common strategy in a countercurrent chromatography (CCC) analysis. However, the solvent selectivity of solvent system is often ignored, despite its significant impact on the separation efficiency of CCC. In this study, the role of solvent in the overall properties of solvent system and the selective classification of solvent system were discussed to improve the solvent system selection based on polarity. Firstly, the mathematical relationship between logarithm of the partition coefficient (log K) of the template molecule and solvent composition of n-hexane/ethyl acetate/alcohol solvents (methanol, ethanol, and isopropanol)/water (HEAwat) system was analyzed and the optimal solvent system (K = 1) of the template molecules was determined. Then, the actual methanol concentration at the column inlet when the analyte peak in a HPLC analysis (B%) and the clustering results of the average polarity (P') of the optimal CCC solvent system were analyzed. Finally, the classification of HEAWat system in terms of its overall solvent properties by deducing equations of selectivity parameters (χ e , χ d , and χ n) to explain the P' values clustering results. The results showed that HEAWat system was suitable for the separation of analytes with 55 % < B % < 100 %. However, the n-hexane/ethyl acetate/isopropanol/water (HEIWat) system proved more suitable for the separation of large polar compounds to other HEAWat system when the P' value decreased due to the change of alcohol solvents. The selected solvent systems were classified into group III and IV by Snyder's method. The solvent systems in group III were suitable for the separation of analytes with 85 % < B % < 100 %, and the distribution behavior of analytes was mainly influenced by the ratio of each solvent. The solvent systems in group IV were suitable for the separation of analytes with 55 % < B % < 85 %, and the distribution behavior of analytes was mainly influenced by the type of alcohol solvents. [ABSTRACT FROM AUTHOR]

• RP UHPLC with three phenyl-bonded stationary phases for oligonucleotides separation. • The highest retention and best peak symmetry of oligonucleotides for the C18/AR. • The effective separation of positional isomers of oligos in a short time. • Separation and identification of impurities and degradation products by RP UHPLC MS. • The method contributes to a more sustainable approach in oligonucleotide analysis. This manuscript discusses the development of a reversed-phase ultra high-performance liquid chromatography (RP UHPLC) method based on phenyl-bonded stationary phases without ion-pairs for the separation and identification of oligonucleotides. The elimination of ion-pair reagents makes the proposed protocol as more compliant to the principles of green chemistry, compared to the traditional ion-pair reversed-phase liquid chromatography methods (IP RP LC). In detail, three phenyl-based stationary phases were tested, namely a C18/AR (a C18 stationary phase with the addition of aromatic groups), a Phenyl-hexyl, and a Diphenyl. Generally, the retention of oligonucleotides increases with the increase of salt concentration and the decrease of the pH, thus confirming the significant impact of van der Waals interactions, salting-out effect, and π-electrons interactions in the retention mechanism. The highest retention and best peak symmetry were observed for the C18/AR stationary phase, while the lowest retention for the Phenyl-hexyl, with retention influenced by the type of salt in the mobile phase. The obtained methods using C18/AR stationary phases allow for the effective separations of positional isomers and for identifying impurities and degradation products using RP UHPLC Q-TOF-MS in a comparatively short time. The application of RP UHPLC Q-TOF-MS provides reasonable selectivity for the resolution of 33 impurities and two degradation products. Both groups of compounds are mainly 3′N and 5′N-shortmers, but in the case of impurities, modifications of cyclic phosphate and phosphate groups were also identified. Nevertheless, Diphenyl and Phenyl-Hexyl may be applied to separate modified oligonucleotides with higher salt concentrations. The proposed separation methods without ion-pair reagents contribute to a more sustainable approach in oligonucleotide analysis. [ABSTRACT FROM AUTHOR]

• Eletromembrane extraction was used to treat hydroxypolycyclic aromatic hydrocarbons. • High extraction efficiency and excellent sample clean-up ability were confirmed. • Urinary hydroxypolycyclic aromatic hydrocarbons were successfully determined. • This method showed high sensitivity and high precision. Polycyclic aromatic hydrocarbons (PAHs) have been classified as the earliest discovered class of environmental carcinogens, seriously endangering human health and ecological safety, and the hydroxylpolycyclic aromatic hydrocarbons (OH-PAHs) in human urine are considered as the main biomarkers to evaluate the exposure levels of PAHs in human body. Therefore, it is necessary to develop an accurate and sensitive method for the determination of urinary OH-PAHs. Herein, we proposed electromembrane extraction (EME) as a simple, effective and ecofriendly sample pretreatment technique for selective extraction, purification and enrichment of four typical OH-PAHs (2-naphthol, 2- and 3-phenanthrol, 2-hydroxyfluorene) in human urine for the first time. Under the optimum conditions, an analytical method of EME coupled with HPLC was established, which provided wide linear ranges for four OH-PAHs from 1 to 500 ng mL-1 with low LODs of 0.05–0.3 ng mL-1. The average recoveries of four OH-PAHs at three spiked levels in human urine were 81.6–102.5% with RSDs all below 9.4%. The present method has been successfully applied for the sensitive determination of trace four OH-PAHs in urine samples from non-smokers and smokers with a maximum concentration of 2.24 and 3.56 ng mL-1, respectively, which showed a great potential for the analysis of trace OH-PAHs in biological samples. [ABSTRACT FROM AUTHOR]

• An efficient procedure to isolate OVTX-a from O. cf. ovata cell pellets was established. • Good practice for sample preparation for each chromatographic steps was detailed. • Good OVTX-a recovery yields at high purity grade were achieved. • In dept characterization of the end-product by LC HRMSn was performed. • The procedure is suitable to produce enough OVTX-a for well characterized RM. Ostreopsis cf. ovata , a benthic/epiphytic marine dinoflagellate, is currently spreading in tropical, sub-tropical and temperate areas, causing periodic Harmful Algal Blooms (HABs). It produces a wide array of palytoxin-like compounds named ovatoxins (OVTXs), with OVTX-a generally the most abundant congener. Despite numerous cases of human poisonings and environmental damage associated with the presence of OVTXs and O. cf. ovata proliferations, a complete characterization of the toxicity of this class of molecules cannot be performed until Reference Material (RM) for individual congeners is available. This, in turn, requires the availability of sufficient amounts of toxin at a high purity grade. To achieve this goal, herein an analytical re-evaluation of critical-steps of OVTX-a isolation from O. cf. ovata cell pellets is reported. The overall procedure consists of four steps, namely an extraction, a Medium Pressure Liquid Chromatography (MPLC) separation, and two preparative High Performance Liquid Chromatography (HPLC) steps. Particular attention was paid to the extraction step to evaluate the repeatability in OVTX-a yields. For subsequent steps, loading sample preparation and chromatographic conditions were refined. As a result, a significant increase in recovery yields (from 12.5 to 20 ± 3%) and in purity grade (from 51% to 94%) of the isolated OVTX-a was achieved in comparison to previous studies. The improved procedure can easily be applied to isolate sufficient quantities of a good candidate RM for OVTX-a. [ABSTRACT FROM AUTHOR]

• Two materials were obtained by regulating chemical microenvironment of cellulose. • The two columns exhibit excellent chromatographic separation performance in different modes. • The various interactions were explained by non-covalent interaction analysis. • Two columns possess excellent stability and potential for analyzing real samples. To deal with complicated separation situations, this study successfully prepared two mixed-mode chromatography (MMC) stationary phases, CCL-SIL and PCL-SIL, by functionalizing dialdehyde cellulose (DAC) derivatives. In liquid chromatography applications, CCL-SIL exhibited superior separation performance for nucleosides and bases in HILIC mode, while PCL-SIL performed better in RPLC and IEC modes. Their distinct separation mechanisms were also elucidated by quantum chemical calculations. Both CCL-SIL and PCL-SIL showed good stability and reproducibility, with relative standard deviations of retention time, peak area, and peak height below 7.79 % and 4.37 % for multiple injections. Particularly, the PCL-SIL column and the CCL-SIL column were successfully used for the quantitative analysis of trace targets in real samples with complex matrix, demonstrating high accuracy and precision. [ABSTRACT FROM AUTHOR]

• HILIC enhances glycopeptide enrichment and glycan separation efficiency. • Advanced HILIC materials improve selectivity for glycosylation analysis. • Combining HILIC with other techniques offers comprehensive glycan insights. • Zirconia-coated sorbents boost selectivity for glycopeptides and phosphopeptides. • Future focus: direct glycoprotein enrichment for disease-related studies. Protein glycosylation, one of the most important biologically relevant post-translational modifications for biomarker discovery, faces analytical challenges due to heterogeneous glycosite, diverse glycans, and mass spectrometry limitations. Glycopeptide enrichment by removing abundant hydrophobic peptides helps overcome some of these obstacles. Hydrophilic interaction liquid chromatography (HILIC), known for its selectivity, glycan separations, intact glycopeptide enrichment, and compatibility with mass spectrometry, has seen recent advancements in stationary phases like Amide-80, glycoHILIC, amino acids or peptides for improved HILIC-based glycopeptide analysis. Utilization of these materials can improve glycopeptide enrichment through solid-phase extraction and separation via high-performance liquid chromatography. Additionally, using glycopeptides themselves to modify HILIC stationary phases holds promise for improving selectivity and sensitivity in glycosylation analysis. Additionally, HILIC has capability to assess the information about glycosites and structural information of glycans. This review summarizes recent breakthroughs in HILIC stationary materials, highlighting their impact on glycopeptide analysis. Ongoing research on advanced materials continues to refine HILIC's performance, solidifying its value as a tool for exploring protein glycosylation. [ABSTRACT FROM AUTHOR]

• Dicationic ionic liquid derived from 1,2-Diaminocyclohexane was synthesized. • The ionic gel was first modified silica as a stationary phase for HPLC. • The stationary phase can operate under the mixed mode of RPLC/HILIC/IC. • The stationary phase exhibited exceptional repeatability in PALC. In this study, we synthesized and employed an ionic gel-functionalized silica stationary phase for high-performance liquid chromatography. The successful fabrication of the stationary phase was confirmed through attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), zeta-potential measurements, and elemental analysis (EA). Comparative performance evaluation against a commercial column demonstrated the prepared column's effectiveness in the mixed mode of reversed-phase liquid chromatography (RPLC), hydrophilic interaction liquid chromatography (HILIC), and ion chromatography (IC). Moreover, the stationary phase exhibited exceptional retention repeatability in per aqueous liquid chromatography, showcasing its potential as an environmentally friendly analytical method. Mechanistic investigations unveiled multiple solute-stationary phase interactions, including π-π interactions, hydrogen bonding, and ion exchange. Finally, we applied the developed stationary phase for the precise detection of preservatives in carbonated beverages and jelly, achieving high levels of accuracy and recovery rates. [ABSTRACT FROM AUTHOR]

• Magnetic hierarchical pores carbon materials synthesized by a self -sacrificing template method. • Rapid and efficient adsorption is possible with a small amount of adsorbent. • The material has good stability and regenerative properties. • Pore filling, hydrogen bond, and hydrophobic interactions enhance the adsorption of BUs. The high speed enrichment of benzoylurea insecticides (BUs) in complex matrices is an essential and challenging step. The present study focuses on the synthesis of a hierarchical pore nitrogen-doped carbon material for magnetic solid phase extraction (MSPE) of BUs. This material was prepared through the carbonization of a composite material ZIF-67@MCA which assembly with hydrogen-bonded organic frameworks (melamine-cyanurate, MCA) and zeolitic imidazolate framework (ZIF-67) at room temperature. The optimal adsorption effect is achieved when the mass ratio of ZIF-67 to MCA is 1/3, and the carbonization was performed at 600 °C, the such obtained carbon material was denoted as 1/3ZIF-67@MCA-DCs-600. The material was characterized with various physical methods including X-ray diffractometry (XRD), Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), vibrating sample magnetometer (VSM), water contact angle measurement, Raman spectrometry. 1/3ZIF-67@MCA-DCs-600 exhibits a macro-mesoporous 3D structure with a high degree of nitrogen doping and relatively large specific surface area, making it suitable for magnetic solid phase extraction (MSPE). The adsorption of BUs with concentration of 100 ng mL-1 can reach equilibrium within 5 s. The interaction between BUs and the adsorbent, facilitated by π-π stacking, hydrophobic interactions, hydrogen bonding forces, as well as the material's porosity, enables efficient extraction recoveries ranging from 45 % to 92 %. The enrichment of BUs was achieved through the establishment of an MSPE method under optimized conditions, which was further coupled with high performance liquid chromatography (HPLC) for the determination of the four BUs. The linear range spans from 5 ng ml-1 to 1000 ng ml-1 with the correlation coefficient (R2) of ≥ 0.99, Meanwhile, the detection limit for these four BUs falls within the range of 0.01 to 0.10 ng ml-1. The material exhibits good reusability and can be reused for at least 5 cycles. Inter day and intra-day precision ranges from 2.1-7.9 % and 1.0-5.4 %, respectively. The method demonstrates a high level of reliability in practical applications for the determination of BUs. [ABSTRACT FROM AUTHOR]

• UAE is the most advanced method used today for the extraction of kaempferol. • The best extraction yield for kaempferol was achieved (under reflux). • HPLC remains immeasurably the most robust approach for quantification. • Kaempferol is primarily sourced from the Asteraceae and Fabaceae families. • Among plant flavonoids, kaempferol is a potent health benefits. As a naturally widely-occurring dietary, cosmetic, and therapeutic flavonoid, kaempferol has gained much consideration for its nutritional and pharmaceutical properties in recent years. Although there have been performed a high number of studies associated with different aspects of kaempferol's analytical investigations, the lack of a comprehensive summary of the various methods and other plant sources that have been reported for this compound is being felt, especially for many biological applications. This study, aimed to provide a detailed compilation consisting of sources (plant species) and analytical information that was precisely related to the natural flavonoid (kaempferol). There is a trend in analytical research that supports the application of modern eco-friendly instruments and methods. In conclusion, ultrasound-assisted extraction (UAE) is the most general advanced method used widely today for the extraction of kaempferol. During recent years, there is an increasing tendency towards the identification of kaempferol by different methods. [ABSTRACT FROM AUTHOR]

• Two types of active flow splitter pumps at the interface of an LC × LC system were studied. • A binary HPLC pump located before the modulation valve was appropriate. • A high precision syringe pump located after the modulation valve can be used. • Countercurrent flow connections lead to better reproducibility and less peak dispersion. • Higher reproducibility was achieved by filling 50 to 75 % of the loop volume. The rapid growth in the use of two dimensional liquid chromatography (2D-LC) applied to the analysis of moderately to highly complex mixtures, has been fueled by continuous improvements in performance and robustness of the instrument components, as well as the ease-of-use of software necessary for controlling the 2D-LC instrument hardware, and analysis of the large data files that result from this type of work. This work has focused on the evaluation of the performance of an online full comprehensive mode (LC×LC), when an active modulation is implemented using a flow splitter pump placed after the 1D effluent. Two different types of splitting pumps were evaluated: a binary ultra-high pressure liquid chromatography (UHPLC) pump and a high precision syringe pump. We analyzed the performance (reproducibility in peak area and retention times and the 2D peak dispersion) as a function of the location of the active pump Before or After the modulation valve, and the influence of connecting tubes (based on internal diameter and length) necessary between the interface, waste, and the splitting pump. The effect on the flow direction on the filling and flushing of the injection loops at the modulation valve was also analyzed for each pump. In this study, we demonstrate that flow-splitting LCxLC assembly can be performed using either a UHPLC binary pump or a simple syringe pump. Flow splitting after the first dimension is a straightforward strategy to: (i) independently select the 1D column and flow rates with respect to the second dimension; (ii) consciously dilute the eluate according to the solvent characteristics of the second dimension, thereby avoiding 2D peak distortions; and (iii) adapt the injected amount to the second column according to the relative concentration of the components in a complex sample. However, careful consideration of the system setup is necessary. It is demonstrated how experimental results can be significantly affected in terms of peak broadening and reproducibility if optimization of the interface is not taken into account. In addition, under the optimized conditions, the reproducibility in peak area and dispersion in the 2D dimension were evaluated as a function of the amount of sample transferred in terms of percentage of filled loop. [ABSTRACT FROM AUTHOR]

• 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]

• 2-MIDHP was used as an elution buffer additive in protein A chromatography. • 2-MIDHP reduced IgG1 aggregation by six-fold, during low pH hold post step. • Addition of 2-MIDHP maintained consistent mAb recovery rates, HCP clearance. • Addition of 2-MIDHP improved the thermal stability of mAbs under acidic conditions. This study investigates the impact of 2-methyl imidazolium dihydrogen phosphate (2-MIDHP) on monoclonal antibody (mAb) aggregation during the Protein A purification stage, at a low pH (pH 3.0), and the viral inactivation phase. Size-exclusion high-performance liquid chromatography (SE-HPLC) and dynamic light scattering (DLS) were used to assess the mAb aggregation. Additionally, the influence of 2-MIDHP on mAb recovery, host cell protein (HCP) clearance, and Protein A leaching was investigated. Thermal stability of mAb, eluted in buffers containing 5 % to 25 % 2-MIDHP was analysed, using differential scanning calorimetry (DSC). Structural insights were obtained via circular dichroism (CD) and fluorescence spectroscopy. Our findings indicated that 2-MIDHP exerted a concentration-dependent protective effect against mAb aggregation, at the pH of 3.0. As the concentration of 2-MIDHP was increased from 0 % to 25 %, the aggregation was significantly reduced from 3.8 ± 0.01 % to 0.56 ± 0.002 %, as analysed by SE-HPLC. Addition of 2-MIDHP did not significantly impact the mAb recovery, HCP clearance, or Protein A leaching. DSC data supported these results, with higher 2-MIDHP concentrations leading to increased melting temperatures of mAb. CD and fluorescence spectroscopy revealed no significant changes in the secondary structure or aromatic residue environment in 2-MIDHP-treated samples, despite the observed reduction in aggregation. The results suggested that 2-MIDHP mitigated mAb aggregation during Protein A purification, possibly by stabilizing the protein structure under acidic stress conditions. These findings offer valuable insights for improving the robustness of mAb purification processes, enhancing product quality and yield. [ABSTRACT FROM AUTHOR]

• HPLC method for 16 kinds of polyphenols has been developed. • Proposed method has good system suitability, and high linearity, precision, and accuracy. • Successfully to quantify 16 polyphenols in 9 tomato varieties. • Different polyphenols composition and content were observed in different tomato varieties. The main purpose of the current work was to develop a new method to evaluate and quantify sixteen polyphenol compounds from tomato fruit using high-performance liquid chromatography (HPLC). The separation of 16 polyphenols from tomato fruit was achieved in < 60 min by using a Waters Symmetry C18 column (250 × 4.6 mm i. d, 5 µm particle sizes) with a gradient system of ultrapure water (1 % acetic acid) and 100 % methanol, a temperature of 30 °C, an injection volume of 10 μL and a flow rate of 1.1 mL/min, respectively. The analytical characteristics of evaluation method provide sufficient sensitivity for all tomato polyphenols compounds within normal range 0.1–20 μg·mL−1 (R2≥0.999) with 0.069–0.365 μg·mL−1 LOD, and 0.171–1.106 μg·mL−1 LOQ, with good system suitability (<2 % RSD of retention time, peak area, and tailing factor, 6,000–1,336,000 N , and >1.5 peak resolution), <10 % RSD of precision, stability, repeatability, and robustness, and 99.2 - 105.0 % of recovery. The applicability of this method was demonstrated by the determination of polyphenols in nine cultivars of tomatoes. The results showed that '184′ possessed the highest content of total polyphenols (1249.53 μg·g−1 DW) followed by 'Disease resistance 184′ (1064.93 μg·g−1 DW). The main polyphenol components were rutin, quercetin, gallic acid, chlorogenic acid, 2,5-dihydroxy benzoic acid, caffeic acid and benzoic acid in tomato fruits. In conclusion, this novel HPLC method is useful and acceptable to analyze polyphenols in tomato fruit. [ABSTRACT FROM AUTHOR]

• A strategy was proposed to characterize wide-polarity metabolites of P. vulgaris. • Offline 2D-LC/IM-QTOF-HDMSE enabled characterization of 255 components. • CCS prediction and targeted compounds isolation improved identification accuracy. • HILIC/IM-QTOF-MSE could characterize 17 highly polar compounds. Metabolites identification is crucial to develop functional foods or perform quality control. Prunella vulgaris (Xia-Ku-Cao) is a medicinal and edible plant used as the herbal medicine or main additive in functional beverage. However, current analytical strategies can only on-line characterize tens of compounds, restricted by insufficient chromatographic resolution and low coverage of the mass spectrometric scan methods. This work was designed to characterize the wide-polarity components from the ear of P. vulgaris. The total extract was fractionated by semi-preparative high-performance liquid chromatography into the retained medium-polarity fraction and unretained polar fraction, which were further analyzed by offline two-dimensional liquid chromatography (2D-LC) and hydrophilic interaction chromatography, respectively. Data-independent high-definition MSE of the Vion™ ion mobility time-of-flight mass spectrometer was utilized enabling the high-coverage acquisition of collision-induced dissociation-MS2 data. The offline 2D-LC, configuring the XBridge Amide and HSS T3 columns, gave high orthogonality (0.81) and effective peak capacity (1555). Automatic peak annotation facilitated by the UNIFI™ bioinformatics platform and comparison with 62 reference compounds achieved the efficient and more reliable structural elucidation. We could characterize 255 compounds from P. vulgaris , with numerous phenylpropanoid phenolic acids and triterpenoid O -glycosides newly reported. Especially, collision cross section (CCS) prediction and targeted isolation of three compounds assisted in the identification of 39 groups of isomers. Additionally, 17 hydrophilic compounds, involving oligosaccharides and organic acids, were characterized from the unretained polar fraction. Conclusively, the in-depth metabolites identification of P. vulgaris was accomplished, and the results can benefit the development and better quality control of this valuable plant. [ABSTRACT FROM AUTHOR]

• A novel BINOL-based chiral polyimine macrocycle bonded silica CSP was prepared. • Excell enantioselectivity of the CSP in both NP-HPLC and RP-HPLC. • Good chiral separation complementarity to Chiralpak AD-H and Chiralcel OD-H columns. • Great potential of BINOL-based chiral macrocycle for HPLC enantioseparation. Macrocycles play vital roles in supramolecular chemistry and chromatography. 1,1′-Bi-2-naphthol (BINOL)-based chiral polyimine macrocycles are an emerging class of chiral macrocycles that can be constructed by one-step aldehyde-amine condensation of BINOL derivatives with other building blocks. These macrocycles exhibit good characteristics, such as facile preparation, rigid cyclic structures, multiple chiral centers, and defined molecular cavities, that make them good candidates as new chiral recognition materials for chromatographic enantioseparations. In this study, a BINOL-based [2+2] chiral polyimine macrocycle was synthesized by one-step condensation of enantiopure (S)-2,2′-dihydroxy-[1,1′-binaphthalene]-3,3′-dicarboxaldehyde with (1R,2R)-1,2-diaminocyclohexane. The product was modified with 5-bromo-1-pentene and then attached to thiolated silica using click chemistry to construct a new chiral stationary phase (CSP). The enantioselectivity of the new CSP was explored by separating various racemates under normal phase (NP) and reversed phase (RP) high performance liquid chromatography (HPLC). Thirteen racemates and eight racemates were enantioseparated under the two separation modes, respectively, including chiral alcohols, phenols, esters, ketones, amines, and organic acids. Among them, nine racemates achieved baseline separation under NP-HPLC and seven racemates achieved baseline separation under RP-HPLC. High resolution separation was observed with benzoin (Rs = 5.10), epinephrine (Rs = 4.98), 3-benzyloxy-1,2-propanediol (Rs = 4.42), and 4,4′-dimethylbenzoin (Rs = 4.52) in NP-HPLC, and with 4-methylbenzhydrol (Rs = 4.72), benzoin ethyl ether (Rs = 3.79), 1-phenyl-1-pentanol (R s = 3.68), and 1-(3-bromophenyl)ethanol (Rs = 3.60) in RP-HPLC. Interestingly, the CSP complemented Chiralcel OD-H, Chiralpak AD-H, and CYCLOBOND I 2000 RSP columns for resolution of these test racemates, separating several racemic compounds that could not be well separated by the three commercially available columns. The influences of injected sample amount on separation were also evaluated. It was found that the column exhibited excellent stability and reproducibility after hundreds of injections, and the relative standard deviations (n = 5) of the retention time and resolution were less than 0.49% and 0.69%, respectively. This study indicates that the BINOL-based chiral macrocycle has great potential for HPLC enantioseparation. [ABSTRACT FROM AUTHOR]

• Magnetic graphene oxide-based covalent organic framework (MGO-COF) was prepared. • The MGO-COF possessed excellent adsorption capacity and fast kinetics for seven pesticides. • The MGO-COF was successfully used for detection of seven pesticides in environmental water. The use of pesticides has increased with the development of agriculture. However, due to the trace content and the matrix's inherent complexity in environmental water, development of rapid and sensitive detection method present significant challenges in the analysis of pesticide residues. The study synthesized magnetic graphene oxide (MGO) by combining superparamagnetic nanoparticles with the easy modification of graphene oxide (GO). Covalent organic frameworks (COFs) were then modified to have a large specific surface area. Finally, magnetic graphene oxide-based covalent organic frameworks, namely MGO-COFs, were obtained with a spherical structure and used as magnetic solid-phase extraction materials, which was successfully used to determine the seven pesticide residues in environmental samples in conjunction with high performance liquid chromatography. The method has a wide linear range for the tested pesticides, with satisfactory correlation coefficients (R ≥ 0.099) and low detection limits (0.3–1.21 μg L−1). The correlation coefficients for all seven pesticides were high (R2 ≥ 0.9996). The spiked recoveries, exhibiting a range of 91.3 to 109 %, demonstrated that the developed MGO-COF-MSPE-HPLC-UV method is simple, efficient, and suitable for the analysis and detection of seven pesticide residues in environmental water. [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]

• An alternative elution mode to conventional HPLC to separate compounds by class. • Sequential elution was utilized to separate classes of compounds in under 15 min. • A tandem-column stationary phase combination (SAX and C18) was utilized. • SAX+C18 and C18+SAX column orientations yielded nearly identical separations. • Retention time and peak area precision were below 1.5 % RSD. This paper discusses the development of an analytical method by an alternative separation approach, sequential elution liquid chromatography (SE-LC), to separate permanently charged ions (anions), weak acids, and neutral compounds using anion exchange and reversed-phase columns in tandem. SE-LC separates classes of compounds by group by employing two or more elution modes. Advantages to using SE-LC over conventional HPLC are a greater peak capacity and a reduced separation disorder. Importantly, the same HPLC as used for a conventional HPLC separation may be used to afford a successful SE-LC separation. Mobile phase selection and gradient optimization are integral for a successful SE-LC class separation of permanent anions, weak acids, and neutral compounds and will be discussed in detail in this paper. The most successful (best resolution and repeatability) SE-LC separation was achieved by applying isocratic elution at low pH to elute the weak acids, followed by an acetonitrile gradient to elute the neutral compounds, and last a sodium methanesulfonate gradient to elute the anionic compounds using a superficially porous C18 column coupled with a strong anion exchange (SAX) column. Repeatability (RSD) in the retention times and peak areas of the analytes was less than 0.25 % and 1.5 %, respectively. [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]

• Zein, a biopolymer protein from corn, was used to construct the liquid chromatography stationary phase. • The PEI/Zein@SiO 2 column displayed good separation for hydrophilic/hydrophobic compounds. • Expanding the potential application of zein in the field of separation analysis. Based on the adhesion of polyethyleneimine (PEI), a novel PEI/zein co-modified core-shell stationary phase (PEI/Zein@SiO 2) was prepared by doping zein to form a composite modification layer. The stationary phase achieved effective separation of nucleosides, bases and antibiotics in hydrophilic interaction mode on account of the hydrophilic groups of composite coating. With the hydrophobicity of zein, the flavones could be separated in reversed-phase mode. In short, the separation and analysis of hydrophilic/hydrophobic compounds were accomplished excellently by the PEI/Zein@SiO 2 column with mixed double mode. The prepared chromatographic stationary phase not only avoided the dissolution of zein, but also covered the strong adsorption of some analytes caused by silica hydroxyl groups on the surface of silica spheres. The morphological structure and specific surface area of the material were reflected by various characterization techniques. Hydrophilic/hydrophobic compounds were used as tested analytes to research separation performance and retention mechanisms of PEI/Zein@SiO 2 column. The stability and reproducibility of the PEI/Zein@SiO 2 stationary phase were satisfied. Therefore, the modification of zein could improve the separation selectivity of stationary phase effectively for complex samples, which had the potential to be one of the significant potential application materials in stationary phase packing. [ABSTRACT FROM AUTHOR]

• Moment analysis theory for mass transfer phenomena of spherical molecular aggregate. • Moment analysis for determining rate constants of interfacial solute permeation. • Measurement of elution peak profiles by high-performance liquid chromatography (HPLC). • Partition equilibrium and permeation kinetics of sodium dodecylsulfate micelle. • Advantages of HPLC and moment analysis for studying permeation of molecular aggregate. A moment analysis method was developed for the study of solute permeation at the interface of spherical molecular aggregates. At first, new moment equations were developed for determining the partition equilibrium constant (K p) and permeation rate constants (k in and k out) of solutes from the first absolute (μ 1A) and second central (μ 2C) moments of elution peaks measured by using high-performance liquid chromatography (HPLC). Then, the method was applied to the analysis of mass transfer phenomena of three solutes, i.e., hydroquinone, resorcinol, and catechol, at the interface of sodium dodecylsulfate (SDS) micelles. HPLC data were measured by using an ODS column and an aqueous phosphate buffer solution (pH = 7.0) as the mobile phase solvent. Pulse response experiments were conducted while changing SDS concentration (5 - 20 mmol dm−3) in the mobile phase under the conditions that the surface of ODS stationary phase was dynamically coated by SDS monomers. In order to demonstrate the effectiveness of the moment analysis method using HPLC, the values of K p , k in , and k out were determined for the three solutes as 35 - 69, 2.4 × 10−8 - 1.4 × 10−6 m s−1, and 7.0 × 10−10 - 2.1 × 10−8 m s−1, respectively. Their values increase with an increase in the hydrophobicity of the solutes. The method has some advantages for the study of interfacial solute permeation of molecular aggregates. For example, neither immobilization nor chemical modification of both solute molecules and molecular aggregates is required when elution peaks are measured by using HPLC. Interfacial solute permeation takes place in the mobile phase without any chemical reaction or physical action on molecular aggregates. The values of K p , k in , and k out were analytically determined from those of μ 1A and μ 2C by using the moment equations. The results of this study must contribute to the dissemination of an opportunity for studying the interfacial solute permeation of molecular aggregates to many researchers because of extremely high versatility of HPLC. [ABSTRACT FROM AUTHOR]

• Sea urchin shaped MMON-PANI is successfully synthesized for MSPE of NSAIDs. • Hydrogen bonding, π-π, hydrophobic, and electrostatic interactions play important roles during MSPE. • Efficient determination of NSAIDs in complex animal-derived food samples is achieved. In this work, a novel polyaniline-modified magnetic microporous organic network (MMON-PANI) composite was fabricated for effective magnetic solid phase extraction (MSPE) of five typical nonsteroidal anti-inflammatory drugs (NSAIDs) from animal-derived food samples before high performance liquid chromatography (HPLC) detection. The core-shell sea urchin shaped MMON-PANI integrates the merits of Fe 3 O 4 , MON, and PANI, exhibiting large specific surface area, rapid magnetic responsiveness, good stability, and multiple binding sites to NSAIDs. Convenient and effective extraction of trace NSAIDs from chicken, beef and pork samples is realized on MMON-PANI via the synergetic π-π, hydrogen bonding, hydrophobic, and electrostatic interactions. Under optimal conditions, the MMON-PANI-MSPE-HPLC-UV method exhibits wide linear ranges (0.2–1000 μg L−1), low limits of detection (0.07–1.7 μg L−1), good precisions (intraday and inter-day RSDs < 5.4 %, n = 3), large enrichment factors (98.6–99.9), and less adsorbent consumption (3 mg). The extraction mechanism and selectivity of MMON-PANI are also evaluated in detail. This work proves the incorporation of PANI onto MMON is an efficient way to promote NSAIDs enrichment and provides a new strategy to synthesize multifunctional MON-based composites in sample pretreatment. [ABSTRACT FROM AUTHOR]

• The miniaturization of HPLC, thought c-LC and n-LC provide green methodologies. • The LC sample treatment can be performed on-line and off-line. • IT- SPME minimize sample treatment and allows to inject the sample directly. • Most of environmental contaminants found are non-regulated compounds. The greater and more widespread use of chemicals, either from industry or daily use, is leading to an increase in the discharge of these substances into the environment. Some of these are known to be hazardous to humans and the environment and are regulated, but there is a large and increasing number of substances which pose a potential risk even at low concentration and are not controlled. In this context, new techniques and methodologies are being developed to deal with this concern. Miniaturized liquid chromatography (LC) emerges as a greener and more sensitive alternative to conventional LC. Furthermore, advances in instrument miniaturization have made possible the development of portable LC instrumentation which may become a promising tool for in-situ monitoring. This work reviews the environmental applications of miniaturized LC over the last 15 years and discusses the different instrumentation, including off- and on-line pretreatment techniques, chromatographic conditions, and contributions to the environmental knowledge. [ABSTRACT FROM AUTHOR]

• Apt-MIP had both biorecognition and chemorecognition ability. • Apt-MIP exhibited higher selectivity than that with one recognition element. • Apt-MIP showed remarkable enrichment factor compared with commercial fibers. • Apt-MIP was successfully applied to detect17β-estradiol from meat samples. In this study, an enhanced selective recognition strategy was employed to construct a novel solid-phase microextraction fiber coating for the detection of 17β-estradiol, characterized by the combination of aptamer biorecognition and molecularly imprinted polymer recognition. Benefiting from the combination of molecularly imprinted and aptamer, aptamer-molecularly imprinted (Apt-MIP) fiber coating had synergistic recognition effect. The effects of pH, ion concentration, extraction time, desorption time and desorption solvent on the adsorption capacity of Apt-MIP were investigated. The adsorption of 17β-estradiol on Apt-MIP followed pseudo-second order kinetic model, and the Freundlich isotherm. The process was exothermic and thermodynamically spontaneous. Compared with polymers that only rely on imprinted recognition, non-imprinted recognition or aptamer affinity, Apt-MIP had the best recognition performance, which was 1.30–2.20 times that of these three materials. Furthermore, the adsorption capacity of Apt-MIP for 17β-estradiol was 885.36–1487.52 times than that of polyacrylate and polydimethylsiloxane/divinylbenzone commercial fiber coatings. Apt-MIP fiber coating had good stability and could be reused for more than 15 times. Apt-MIP solid-phase microextraction coupled with high-performance liquid chromatography was successfully applied to the determination of 17β-estradiol in pork, chicken, fish and shrimp samples, with satisfactory recoveries of 79.61 %–105.70 % and low limits of detection (0.03 μg/kg). This work provides new perspectives and strategies for sample pretreatment techniques based on molecular imprinting technology and improves analytical performance. [ABSTRACT FROM AUTHOR]

• The microchip integrating Z-shaped cell, micro-lenses and optical slits is small in size. • The on-chip optical design can extend optical path length and block stray light. • The detector showed excellent linearity and LOD, low stray light and noise levels. • HbA 1c levels can be accurately and quickly detected by this detector. A miniaturized microchip-based absorbance detector was developed for portable high-performance liquid chromatography (HPLC) to test glycated hemoglobin (HbA 1c). The microchip integrating a Z-shaped cell, two collimating micro-lenses and two ink-filled optical slits is small in size (30 mm × 15 mm × 7 mm). The Z-shaped cell has a cross-sectional size of 500 μm × 500 μm and a physical optical path length of 2 mm. Two collimating micro-lenses were inserted in empty grooves on both sides of the cell, one micro-lens for collimating the initial light and the other for focusing the transmitted light. Optical slits on each end of the cell were used to block the stray light. Therefore, this detector indicated a low stray light level (0.011 %) and noise level (2.5 × 10−4 AU). This detector was applied for the commercial HPLC system to detect HbA 1c level, and showed a low limit of detection (0.5 μg/mL) and excellent repeatability (≤ 2.03 %). The sensitivity was enhanced by 3.4 times when the optical path length was increased from 0.5 mm to 2 mm and the stray light was blocked by optical slits. The miniaturized microchip-based absorbance detector developed shows a great potential for application in portable and compact HPLC. [ABSTRACT FROM AUTHOR]

• CS/CD/MIL-68(Al) foam column was prepared and firstly evaluated as an adsorbent in SPE. • CS/CD/MIL-68(Al) foam column reduced the pressure of traditional SPE column. • CS/CD/MIL-68(Al) foam column was water stable, pollution-free, and biodegradable. • CS/CD/MIL-68(Al) foam column was durable and can be used effectively at least 5 times. This study describes the preparation of a cylindrical polymer foam column termed Chitosan/β-Cyclodextrin/MIL-68(Al) (CS/β-CD/MIL-68(Al)). An ice template-freeze drying technique was employed to prepare the CS/β-CD/MIL-68(Al) foam column by embedding MIL-68(Al) in a polymer matrix comprising cross-linked chitosan (CS) and β-cyclodextrin (β-CD). The cylindrical CS/β-CD/MIL-68(Al) foam was subsequently inserted into a syringe to develop a solid phase extraction (SPE) device. Without the requirement for an external force, the sample solution passed easily through the SPE column thanks to the porous structure of the CS/β-CD/MIL-68(Al) foam column. Moreover, the CS/β-CD/MIL-68(Al) foam column was thought to be a superior absorbent for SPE since it included the adsorptive benefits of CS, β-CD, and MIL-68(Al). The SPE was utilized in conjunction with high-performance liquid chromatography to analyze six sulfonamides found in milk, urine, and water. With matrix effects ranging from 80.49 % to 104.9 % with RSD values of 0.4–14.0 %, the method showed high recoveries ranging from 80.6 to 107.4 % for water samples, 93.4–105.2 % for urine, and 87.4–100.9 % for milk. It also demonstrated good linearity in the range of 10–258 ng·mL-1 with the limits of detection ranging from 1.88 to 2.58 ng·mL-1. The cylindrical CS/β-CD/MIL-68(Al) foam column prepared in this work offered several advantages, including its simple fabrication, excellent water stability, absence of pollutants, biodegradability, and reusability. It is particularly well-suited for SPE. Furthermore, the developed SPE method, employing CS/β-CD/MIL-68(Al) foam column, is straightforward and precise, and its benefits, including affordability, ease of preparation, lack of specialized equipment, and solvent economy, underline its broad applicability for the pretreatment of aqueous samples. [ABSTRACT FROM AUTHOR]

• Optimisation of the separation based on global models was carried out. • A green tea sample was used as representative of the teas in the optimisation. • Expected and actual separations matched well. • Optimised chromatogram is used to classify 40 samples of 6 tea varieties. • Satisfactory results with supervised and unsupervised classificatory techniques. As a result of their metabolic processes, medicinal plants produce bioactive molecules with significant implications for human health, used directly for treatment or for pharmaceutical development. Chromatographic fingerprints with solvent gradients authenticate and categorise medicinal plants by capturing chemical diversity. This work focuses on optimising tea sample analysis in HPLC, using a model-based approach without requiring standards. Predicting the gradient profile effects on full signals was the basis to identify optimal separation conditions. Global models characterised retention and bandwidth for 14 peaks in the chromatograms across varied elution conditions, facilitating resolution optimisation of 63 peaks, covering 99.95 % of total peak area. The identified optimal gradient was applied to classify 40 samples representing six tea varieties. Matrices of baseline-corrected signals, elution bands, and band ratios, were evaluated to select the best dataset. Principal Component Analysis (PCA), k -means clustering, and Partial Least Squares-Discriminant Analysis (PLS-DA) assessed classification feasibility. Classification limitations were found reasonable due to tea processing complexities, involving drying and fermentation influenced by environmental conditions. [ABSTRACT FROM AUTHOR]

• New LC-MS/MS validated quantification method of psilocin in plasma is developed. • Tryptophan interference prevented the use of reversed phase chromatography. • Interference by tryptophan is identified for the first time. • Hydrophilic interaction liquid chromatography resolved tryptophan and psilocin. • A 0.5 ng/mL lower limit of quantification is achieved. • The quantification method is successfully applied to mouse plasma samples. Psilocybin is a psychedelic compound found in some hallucinogenic "magic mushrooms". Psilocin is the active metabolite of Psilocybin, and it is the subject of several studies for the treatment of psychological disorders, such as anxiety, depression, and post-traumatic stress disorder. As such, the pharmacokinetic properties of psilocin should be evaluated to ensure its safety and efficacy as part of the drug development process. Based on the previously published studies, reversed-phase liquid chromatography (LC) was tested for psilocin quantification. The analysis, however, showed a major interference in mouse plasma that was not, to the best of our knowledge, reported previously. We, therefore, aimed to identify and separate the interference, using various chromatographic columns, mobile phase conditions, and mass spectrometers (MS) instruments. Chromatographic separation was achieved on an ultra high performance liquid chromatography (UHPLC) system, and a quadrupole-linear ion trap equipped with an electrospray ionization (ESI) source was used in positive ion mode with multiple reaction monitoring (MRM). Several chromatographic conditions and column chemistries, including C-18 and Phenyl-hexyl were initially tested, and failed to separate the interference. Exact mass measurement and MS/MS analysis were used to determine the structure of the interfering compound, which was confirmed to be tryptophan. Using the identified structure of the interfering compound, a fast and reliable hydrophilic interaction liquid chromatography (HILIC)-MS/MS method was developed and validated, that was capable of separating psilocin from the interference while achieving a 0.5 ng/ml lower limit of quantification (LLOQ). The validated method was successfully applied to a pharmacokinetic study where psilocin was orally administered to C57BL/6 mouse subjects. Psilocin concentration in all the analyzed mouse plasma samples was successfully determined. [ABSTRACT FROM AUTHOR]

• Magnetic surface-imprinted polymer microspheres (Fe 3 O 4 @MIPs) were facilely prepared. • Fe 3 O 4 @MIPs showed enhanced selectivity, rapid extraction and good reusability for amphetamines. • A selective magnetic solid-phase separation method was developed for six amphetamines in water samples. • The method offers a shorter extraction time for analyzing amphetamines in water compared to other methods. Magnetic surface imprinted polymer microspheres (Fe 3 O 4 @MIPs) were successfully synthesized via Pickering emulsion polymerization, utilizing N-Methylphenethylamine as a surrogate template for amphetamine-type drugs. Fe 3 O 4 @MIPs not only possessed excellent dispersibility and enough magnetic properties in aqueous solutions, but also displayed good selectivity towards six amphetamines, with an imprinting factor ranging from 1.8 to 2.6. The adsorption kinetics closely aligned with the pseudo-second-order model, and the adsorption efficiency exceeds 80 % for each amphetamine at equilibrium. Fe 3 O 4 @MIPs were then employed as the efficient adsorbents for the extraction of amphetamine drugs. Extraction parameters, including sample pH, the mass of adsorbent, and the type and volume of eluting solvent, were carefully optimized. In combination with the high performance liquid chromatography tandem triple quadrupole mass spectrometry (HPLC-MS/MS), a selective magnetic solid-phase extraction (MISPE) method utilizing Fe 3 O 4 @MIPs was developed for the detection of six amphetamines in water samples. The limits of detection and limits of quantitation were determined to be 5.2∼23 ng L−1 and 17∼77 ng L−1, respectively. Recoveries for the six target drugs from lake water and sewage samples fell within the range of 87.2∼110 %. Additionally, the MISPE-HPLC-MS/MS method exhibited excellent repeatability, with a precision below 8.5 % at two spiking levels. The prepared Fe 3 O 4 @MIPs possessed the advantages of high selectivity, straightforward preparation, facile separation and good reusability, and was highly suitable for the efficient extraction of amphetamine-type substances in complex environmental water. [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 novel fluorinated CTFs was fabricated for extraction of fluoroquinolones. • Abundant fluorine affinity sites endow its high selectivity for extraction. • A PT-SPE-HPLC method was established to sensitively determine fluoroquinolones. A novel fluorinated triazine-based covalent organic frameworks (F-CTFs) was designed and synthesized by using melamine and 2,3,5,6-tetrafluoroterephthalaldehydeas as organic ligands for selective pipette tip solid-phase extraction (PT-SPE) of amphiphilic fluoroquinolones (FQs). The competitive adsorption experiment and mechanism study were carried out and verified that this F-CTFs possesses favorable adsorption affinity for FQs. The abundant fluorine affinity sites endowed the F-CTFs high selectivity to FQs extraction through F-F interactions. The adsorption capacity of F-CTFs can reach up to 109.1 mg g −1 for enrofloxacin. The detailed characterization of the F-CTFs adsorbent involved the application of various techniques to examine its morphology and structure. Under optimized conditions, a method combining F-CTF-based PT-SPE with high-performance liquid chromatography (PT-SPE-HPLC) was established, which exhibited a broad linear range, excellent precision, and an impressively low limit of detection, and could be used for the determination of six FQs in milk, with LODs as low as 0.0010 μg mL−1. The recovery rates during extraction varied between 92.1% and 111.4%, exhibiting RSDs below 6.8% at different spiked concentrations. [ABSTRACT FROM AUTHOR]

• Effect of deuteration degree of amphetamine on isotope effect in HPLC was studied. • Effect of structure of analyte, mobile phase and chiral selector on isotope effect in HPLC was studied. • Possible mechanisms of separation of isotopologues and enantiomers were studied. Hydrogen/deuterium (H/D) isotope effects are not unusual in chromatography and such phenomena have been observed in both gas- and liquid-phase separations. Despite the numerous reports on this topic, the understanding of mechanisms and the underlying noncovalent interactions at play remains rather challenging. In our recent study, we reported baseline separation of isotopologoues of some amphetamine (AMP) derivatives on achiral and polysaccharide-based chiral columns, as well as some correlations between the degree of separation of enantiomers and isotopologues on (the same) polysaccharide-based chiral column(s). Following our previous findings on isotope effects in high-performance liquid chromatography, we report herein a comparative study on the isotope effects observed with AMP and methamphetamine (MET). The impact of some pivotal factors such as the number of deuterium atoms part of AMP isotopologues, the structure of its isotopomers, the chemical structure of the achiral and chiral stationary phases used in this study, and the use of methanol- vs acetonitrile-containing mobile phases on the isotope effects was examined and discussed. Quantitative correlations between the observed isotope effects and the enantioselectivity of the chiral columns used are also shortly discussed. Furthermore, considering the chromatographic results as benchmark experimental data, we attempted to elucidate the molecular bases of the observed phenomena using quantum mechanics calculations. [ABSTRACT FROM AUTHOR]

• Method developed for PFAS in various food matrices. • Limit of quantification for 4 regulated EFSA PFAS in the lower ng/kg range achieved. • The method can also be used for food contact materials. • The method was applied to food contact material, seaweed samples, eggs and milk. Dietary intake is the major pathway of human exposure to per- and polyfluoroalkyl substances (PFAS). Due to their generally very low concentrations in food, especially for foods of plant origin, and their toxicological relevance, demand is growing for improved selective and sensitive analytical methods for the determination of PFAS in the lower ng/kg range. The relevance is pointed out due to the fact that the European Commission has published limits of quantification (LOQs) in the lower ng/kg range for different food matrices in Recommendation (EU) 2022/1431 on the monitoring of perfluoroalkyl substances in food. For example, LOQs of 2 ng/kg for perfluorooctanesulfonic acid (PFOS), 1 ng/kg for perfluorooctanoic acid (PFOA), 1 ng/kg for perfluorononanoic acid (PFNA) and 4 ng/kg for perfluorohexanesulfonic acid (PFHxS) in fruit, vegetables and baby foods are required. A new, very sensitive method is presented here for the determination of 22 PFAS in food and food contact materials. The method is based on liquid-solid extraction and automated clean-up using two solid phase extraction techniques. The analytes are separated and detected by HPLC-MS/MS. A limit of detection (LOD) of 0.33 ng/kg and an LOQ of 1.0 ng/kg are attained for plant foods such as fruits and vegetables as well as for milk and baby food. For foods of animal origin such as egg, meat, fish and paper-based food contact materials an LOD of 1.6 ng/kg as well as an LOQ of 5.0 ng/kg are attained. PFOS and PFOA were the most abundant compounds in the food samples with concentration as high as 1,051 ng/kg of PFOA in sea weed samples and 772 ng/kg of PFOS in eggs samples. In food contact material samples, higher levels were found with a maximum of 310,000 ng/kg PFHxA. In sum the presented method firstly allows determination of PFAS in a wide variety of foodstuffs and paper-based food contact materials at EU-required concentration ranges. [ABSTRACT FROM AUTHOR]

• A conventional HPLC instrument was adapted for 1–10 µL/min flow rates operation. • Active flow splitter and capillary UV–vis cell construction details. • Capillary-scale flow precision with an arduino Uno-based splitter. • Efficient capillary-scale detection compatible with conventional detectors. This study introduces a feasible approach for utilizing a conventional High-Performance Liquid Chromatography (HPLC) instrument at the capillary scale (1 - 10 µL/min). The development of an active flow splitter and an adapted UV-visible (UV–vis) detection cell are described. The system employs an Arduino Uno board to monitor a flow sensor and control a stepper motor that automates a split valve to achieve capillary-scale flow rates from a conventional pump. A capillary UV–vis cell compatible with conventional detectors, featuring an optical path length with a volume of 14 nL, was developed to address the detection challenges at this scale and minimize extra column band broadening. The system performance was assessed by a lab-packed LC capillary column with 0.25 mm x 15 cm dimensions packed with 3.0 µm C18 particles. Model compounds, particularly polycyclic aromatic hydrocarbons (PAHs), were employed to assess the functionality of all developed components in terms of theoretical plates, resolution, and band broadening. The proposed system is a profitable, reliable, and cost-effective tool for miniaturized liquid chromatography. [ABSTRACT FROM AUTHOR]

• A novel online LC setup as a process analytical technology tool is introduced. • Real-time monitoring of critical product attributes during downstream processing. • Development of fast analytical LC methods for various biotherapeutic modalities. The application of Process Analytical Technology (PAT) principles for manufacturing of biotherapeutics proffers the prospect of ensuring consistent product quality along with increased productivity as well as substantial cost and time savings. Although this paradigm shift from a traditional, rather rigid manufacturing model to a more scientific, risk-based approach has been advocated by health authorities for almost two decades, the practical implementation of PAT in the biopharmaceutical industry is still limited by the lack of fit-for-purpose analytical methods. In this regard, most of the proposed spectroscopic techniques are sufficiently fast but exhibit deficiencies in terms of selectivity and sensitivity, while well-established offline methods, such as (ultra-)high-performance liquid chromatography, are generally considered as too slow for this task. To address these reservations, we introduce here a novel online Liquid Chromatography (LC) setup that was specifically designed to enable real-time monitoring of critical product quality attributes during time-sensitive purification operations in downstream processing. Using this online LC solution in combination with fast, purpose-built analytical methods, sampling cycle times between 1.30 and 2.35 min were achieved, without compromising on the ability to resolve and quantify the product variants of interest. The capabilities of our approach are ultimately assessed in three case studies, involving various biotherapeutic modalities, downstream processes and analytical chromatographic separation modes. Altogether, our results highlight the expansive opportunities of online LC based applications to serve as a PAT tool for biopharmaceutical manufacturing. [ABSTRACT FROM AUTHOR]

• Magnetic imprinted polymers (MMIPs) were constructed by two-step immobilization strategy. • The MMIPs possessed excellent adsorption capacity for bisphenol A (BPA). • MMIPs-based method was used for detection of BPA in environmental water and milk. Molecularly imprinted polymer with water-compatibility for effective separation and enrichment of targeted trace pollutants from complicated matrix has captured extensive attention in terms of their high selectivity and matrix compatibility. This study focuses on modified β-cyclodextrin is used as a hydrophilic functional monomer to develop magnetic molecularly imprinted polymers (MMIPs). MMIPs were prepared using Fe 3 O 4 nanoparticles as carriers and bisphenol A (BPA) as templates using a two-step fixation strategy and surface imprinting technology. The structural characteristic and binding properties of the prepared MMIPs were thoroughly studied. The MMIPs exhibited high crystallinity, high adsorption capacity, fast rebinding rate, remarkable selectivity and distinguish reusability. In addition, through magnetic solid-phase extraction separation technology and high-performance liquid chromatography ultraviolet quantitative detection technology, MMIPs are used for selective enrichment and detection of BPA in complex media such as environmental water and milk. This work provides a new route to construct the hydrophilic molecularly imprinted materials and a new sight on developing more effective sample pretreatment strategies for monitoring targeted pollution in complicated aqueous media. [ABSTRACT FROM AUTHOR]

• A dual-chiral COF was designed and synthesised by post-modificating chiral trans-1,2-cyclohexanediamine and (D)-penicillamine onto the COF. • The dual-chiral COF had great separation ability for a range of enantiomers including chiral pharmaceutical intermediates and chiral drugs. • The dual-chiral COF column offer selectivity and durability comparable to some commercially columns. • The dual-chiral COF column had excellent repeatability and high thermal stability over an extended period, supporting its reliability of chiral separation. • The chiral separation mechanism of the dual-chiral COF was investigated by molecular simulations. Developing novel chiral stationary phases (CSPs) with versatility is of great importance in enantiomer separation. This study fabricated a dual-chiral covalent organic framework (PA-CA COF) via successive post-synthetic modifications. The chiral trans-1,2-cyclohexanediamine (CA) and (D)-penicillamine (PA) groups were periodically aligned within nanochannels of the COF, allowing selective recognition of enantiomers through intermolecular interactions. It can be a versatile high-performance liquid chromatography (HPLC) CSP for separating a wide range of enantiomers, including chiral pharmaceutical intermediates and chiral drugs. With separation performance comparable to commercial chiral columns and even greater versatility, the PA-CA COF@SiO 2 column held promise for practical applications. Chiral separation results combined with molecular simulation indicated that the mixed mode of PA and CA resulted in the broad separation capability of PA-CA COF. The introduction of the dual-chiral COFs concept opens up a new avenue for chiral recognition and separation, holding great potential for practical enantiomer separation. [ABSTRACT FROM AUTHOR]

• The in situ growth method was employed to prepare COF-TpPa-1@SiO 2 microspheres. • The microspheres can be used as RP/HILIC mixed-mode stationary phase. • The stationary phase exhibited excellent resolution in separating small solutes. • The stationary phase can enhance the aromatic, shape and planar selectivity. Covalent organic frameworks (COFs) show promise as a stationary phase in high performance liquid chromatography (HPLC). However, there are only a few COFs-based stationary phases developed for HPLC separation so far. Therefore, it is crucial to not only develop more varieties of COFs-type stationary phases for HPLC separation, but also to explore the retention mechanism of solutes on these stationary phases. In this paper, a new in-situ growth method was developed to prepare β -ketoenamine COF-TpPa-1@SiO 2 composite microspheres, using spherical silica as the core material and COF-TpPa-1 fabricated by covalent conjugation of 1,3,5-triformylphloroglucinol (Tp) and p -phenylenediamine (Pa-1) as the COF shells. The resulting microspheres exhibit uniform morphology, good monodispersity, large specific surface area, narrow size distribution, and high stability. Due to diverse functional groups in the structure of COF-TpPa-1, the microspheres can offer multiple interactions, such as hydrophobic, π-π stacking and electron-donor–acceptor (EDA) between COFs and analytes. As a result, the COF-TpPa-1@SiO 2 composite microspheres can be used as a mixed-mode stationary phase for HPLC separation. The chromatographic performance and retention mechanism of the COF-TpPa-1@SiO 2 packed column were investigated by separating polar and non-polar solutes, as well as isomers, in various HPLC modes, including reversed-phase liquid chromatography (RPLC), hydrophilic interaction chromatography (HILIC), and RPLC/HILIC mixed-mode chromatography. The results showed successful separation of non-polar alkylbenzene homologues, polycyclic aromatic hydrocarbons (PAHs), and polar amines and phenols in RPLC mode. The "U-shaped" curves of retention factor with the ACN concentration in mobile phase for four nucleobases indicated that the solute retention on the column followed a mixed mode mechanism of RPLC/HILIC. Compared to a traditional C18 column, the COF-TpPa-1@SiO 2 column exhibited superior separation efficiency, stability, repeatability and reproducibility in the separation of analytes with different polarities. The column enhanced the aromatic, shape and planar selectivity for PAHs and isomers through π-π interaction and improved the separation efficiency for electron-deficient compounds due to EDA effect. At last, the column was successfully used to separate and detect the residues of 5 phenylurea herbicides (PUHs) in soil. All these results indicate the potential of COFs for chromatography applications. [ABSTRACT FROM AUTHOR]

• Solvent and monomer regulation synthesis of core-shelled Fe 3 O 4 @CD-MON was achieved. • Hydrogen bonding, π-π, hydrophobic, and host-guest interactions played important roles during MSPE. • Efficient MSPE and determination of estrogens from complex biological samples was realized. The abnormal estrogens levels in human body can cause many side effects and diseases, but the quantitative detection of the trace estrogens in complex biological samples still remains great challenge. Here we reported the fabrication of a novel core-shell structured magnetic cyclodextrin microporous organic network (Fe 3 O 4 @CD-MON) for rapid magnetic solid phase extraction (MSPE) of four estrogens in human serum and urine samples prior to HPLC-UV determination. The uniform spherical core-shell Fe 3 O 4 @CD-MONs was successfully regulated by altering the reactive monomers and solvents. The Fe 3 O 4 @CD-MONs owned high specific surface area, good hydrophobicity, large superparamagnetism, and abundant extraction sites for estrogens. Under optimal conditions, the proposed MSPE-HPLC-UV method provided wide linearity range (2.0–400 μg L−1), low limits of detection (0.5–1.0 μg L−1), large enrichment factors (183–198), less adsorbent consumption (3 mg), short extraction time (3 min), and good stability and reusability (at least 8 cycles). The established method had also been successfully applied to the enrichment and detection of four estrogens in serum and urine samples with a recovery of 88.4–105.1 % and a relative standard deviation of 1.0–5.9 %. This work confirmed the feasibility of solvent and monomer regulation synthesis of Fe 3 O 4 @CD-MON composites, and revealed the great prospects of magnetic CD-MONs for efficient enrichment of trace estrogens in complex biological samples. [ABSTRACT FROM AUTHOR]

• A fluorescence polarization-based at-line nanofractionation platform was developed. • Semi-HPLC and orthogonal separation were exploited to identify co-eluted compounds. • 28 potential SARS-CoV-2 fusion inhibitors were identified. • 4 potential dual-target inhibitors against influenza and SARS-CoV-2 were found. In this study, a novel at-line nanofractionation platform was established for screening SARS-CoV-2 fusion inhibitors from natural products for the first time by combining HPLC-MS/MS with high-throughput fluorescence polarization (FP) bioassay. A time-course FP bioassay in 384 well-plates was conducted in parallel with MS/MS to simultaneously obtain chemical and biological information of potential fusion inhibitors in Lonicerae Japonicae Flos (LJF) and Lianhua Qingwen capsules (LHQW). Semi-preparative liquid chromatography and orthogonal HPLC separation were employed to enrich and better identify the co-eluted components. After comprehensive evaluation and validation, 28 potential SARS-CoV-2 fusion inhibitors were screened out and identified. Several compounds at low micromolar activity were validated by in vitro inhibitory assay, molecular docking, cytotoxicity test, and pseudovirus assay. Moreover, four potential dual-target inhibitors against influenza and COVID-19 were discovered from LJF using this method, offering novel insights for the development of future pharmaceuticals targeting epidemic respiratory diseases. [ABSTRACT FROM AUTHOR]

• The unique structure of chiral pillar[5]arene provides advantages for inclusion complexation. • The introduction of histidine newly added the enantioseparation ability of pillar[5]arene. • Multiple types of enantiomers were separated by L / D His-BP5-Sil. • Excellent repeatability and stability in both normal and reversed modes. Chiral enantiomers, especially the enantiomers of chiral drugs often exhibit different pharmacological activity, metabolism and toxicity, thus it is of great research significance to scientifically and reasonably develop single chiral drugs with low toxicity and high efficiency. Among them, high performance liquid chromatographic techniques based on chiral stationary phases (CSPs) has become one of the most attractive methods used to evaluate the enantiomeric purity of single-enantiomers compound of pharmacological relevance. In this work, pillar[5]arene functionalized with L- and D-histidine, respectively, were modified on the surface of mesoporous silica as novel chiral stationary phases called L / D His-BP5-Sil. Notably, L / D -histidine had the characteristics of low steric hindrance and easy derivatization. Although the π-π interaction of imidazole group was weaker than that of benzene ring, the benzene ring bonding imidazole-conjugated ring in the structure produced better enantioseparation effect. The results showed that L / D His-BP5-Sil can separate a variety of complex structural enantiomers with excellent reproducibility, thermal stability and separation performance. Hence, the unique advantage of the highly selective separation of L / D His-BP5-Sil provides new insights into the enantioseparation field. [ABSTRACT FROM AUTHOR]

• Good determination of 20 antihistamines was obtain at 8 min by UHPLC. • Dispersive micro solid phase extraction is efficient for extracting antihistamines. • Compared with existing methods, this method showed lower LODs. • Results of antihistamines in milk shown maybe be noteworthy issues for human. Ultrahigh-performance liquid chromatography coupled with high-field quadrupole Orbitrap high resolution mass spectrometry was used for the separation and determination of 20 antihistamines, and a dispersive micro solid-phase extraction procedure using high-performance absorbing material was developed as a sample preparation strategy for extracting 20 antihistamines from milk. Instrument conditions and key parameters influencing extraction efficiency were investigated to obtain an optimized method. The limit of detection for 20 antihistamines in milk using this method is 0.05 µg/L to 1.0 µg/L. Recoveries are between 80.7 % and 108.3 %, and the relative standard deviation is less than 15 %. It is suitable for confirmatory monitoring and quantitative analysis of 20 antihistamines in milk. The results show that antihistamines in milk may be noteworthy issues for human health and environmental pollution. [ABSTRACT FROM AUTHOR]

• Azo-linked porous organic polymer (AL-POP) were incorporated into melamine sponges and used for pipette tip micro solid-phase extraction (PT-MSPE). • Various interactions including hydrogen bonding, electrostatic and π-π stacking using AL-POP. • Synergic effect was observed by incorporating the AL-POP as an adsorbent into the cavities of melamine sponge. • This method is compact, fast, flexible, feasible and environmentally friendly. A novel azo-linked porous organic polymer (AL-POP) was synthesized from caffeic acid and benzidine via an azo-coupling reaction and characterized by FTIR, SEM-EDS, BET, TGA, XRD and zeta potential analysis. AL-POPs were incorporated into melamine sponges and used for pipette tip micro solid-phase extraction (PT-MSPE) of six types of B vitamins (including thiamine, riboflavin, nicotinamide, pyridoxine, folic acid, and cyanocobalamin). After extraction, the samples were analyzed using high performance liquid chromatography-diode array detection (HPLC-DAD) system. The effect of AL-POP composition on the extraction efficiency (EE) of vitamins was investigated and benzidine to caffeic acid mol ratio of 1.5, 3.35 mmol of NaNO 2, and reaction time of 8 h were selected as optimum conditions. The efficiency of the extraction process was improved by optimizing various parameters such as the amount of sorbent, pH and ionic strength of the sample, sample volume, number of sorption and desorption cycles, type of wash solvent, and type and volume of eluent solvent. Linearity (R2≥0.9987), Limit of detection (LOD) (11.88–18.97 ng/mL), limit of quantification (LOQ) (39.62–63.23 ng/mL), and enrichment factor (EF) (1.27–4.31) were obtained using calibration curves plotted under optimum conditions. Recovery values of these six B vitamins in the spiked multivitamin syrup samples varied from 80.01% to 108.35%, with a relative standard deviation (RSD) below 5.44%. Eventually, the optimized method was successfully used to extract and quantify the B vitamins in multivitamin syrup and non-alcoholic beer. [ABSTRACT FROM AUTHOR]

• A highly selective nanocomposite adsorbent was fabricated to extract triazines. • Fe 3 O 4 NH 2 , quantum dots and mesoporous carbon were embedded in imprinted polymer. • The adsorbent was applied in a dispersive magnetic solid phase extraction procedure. • Satisfactory recoveries of spiked fruit juice samples were achieved. • The adsorbent was easy to fabricate, selective, efficient, convenient and rapid. A magnetic molecularly imprinted polymer (MMIP) adsorbent incorporating amino-functionalized magnetite nanoparticles, nitrogen-doped graphene quantum dots and mesoporous carbon (MIP@MPC@N-GQDs@Fe 3 O 4 NH 2) was fabricated to extract triazine herbicides from fruit juice. The embedded magnetite nanoparticles simplified the isolation of the adsorbent from the sample solution. The N-GQDs and MPC enhanced adsorption by affinity binding with triazines. The MIP layer provided highly specific recognition sites for the selective adsorption of three target triazines. The extracted triazines were determined by high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD). The developed method exhibited linearity from 1.5 to 100.0 µg L−1 with a detection limit of 0.5 µg L−1. Recoveries from spiked fruit juice samples were in the range of 80.1– 108.4 %, with a relative standard deviation of less than 6.0 %. The developed MMIP adsorbent demonstrated good selectivity, high extraction efficiency, ease of fabrication and use, and good stability. [ABSTRACT FROM AUTHOR]

• Fe 3 O 4 @MON-NH 2 -OH-MSPE-HPLC was proposed for monitoring the trace ZEN. • Hydrogen bonding, hydrophobic, and π-π interactions dominate the extraction. • Large adsorption capacity of ZEN on Fe 3 O 4 @MON-NH 2 -OH was achieved. Efficient enrichment of trace zearalenone (ZEN) from the complex traditional Chinese medicine (TCM) samples is quite difficult, but of great significance for TCM quality control. Herein, we reported a novel magnetic solid phase extraction (MSPE) strategy for ZEN enrichment using the amino- and hydroxyl dual-functionalized magnetic microporous organic network (Fe 3 O 4 @MON-NH 2 -OH) as an advanced adsorbent combined with the high-performance liquid chromatography (HPLC) determination. Efficient extraction of ZEN was achieved via the possible hydrogen bonding, hydrophobic, and π-π interactions between Fe 3 O 4 @MON-NH 2 -OH and ZEN. The adsorption capacity of Fe 3 O 4 @MON-NH 2 -OH for ZEN was 215.0 mg g−1 at the room temperature, which was much higher than most of the reported adsorbents. Under the optimal condition, the developed Fe 3 O 4 @MON-NH 2 -OH-MSPE-HPLC method exhibited wide linear range (5–2500 μg L−1), low limits of detection (1.4–35 μg L−1), less adsorbent consumption (5 mg), and large enhancement factor (95) for ZEN. The proposed method was successfully applied to detect trace ZEN from 10 kinds of real TCM samples. Conclusively, this work demonstrates the Fe 3 O 4 @MON-NH 2 -OH can effectively extract trace ZEN from the complex TCM matrices, which may open up a new way for the application of MONs in the enrichment and extraction of trace contaminants or active constituents from the complex TCM samples. [ABSTRACT FROM AUTHOR]

• Magnetic H 3 PO 4 -activated biochar (MPBC) was cross-linked with β-cyclodextrin (CD). • MPBC CD-based magnetic SPE was used to extract antiepileptic drugs from plasma. • The adsorption and extraction performance of MPBC CD were investigated. • Chemical calculations were conducted to reveal the adsorption mechanism. • It extended the use of biochar as an eco-friendly matrix in bio-sample analysis. Simultaneous monitoring of plasma concentration levels of multiple antiepileptic drugs (AEDs) is essential for dose adjustment in comprehensive epilepsy treatment, necessitating a sensitive technique for accurate extraction and determination of AEDs. Herein, a magnetic solid-phase extraction (MSPE) technique on the basis of modified biochar (BC) is investigated to extract four AEDs from plasma, in conjunction with high performance liquid chromatography. BC derived from Zizyphus jujuba seed shells was activated by phosphoric acid (PBC) and magnetized via coprecipitation to produce MPBC. The MPBC CD obtained after modification with β-cyclodextrin (CD) was characterized and evaluated for adsorption. It exhibited fast adsorption kinetics based on second-order kinetics and satisfactory adsorption capacity for AEDs. Then it was employed as the MSPE adsorbent and the influencing parameters were optimized. The enrichment factor was 18.75. The validation analysis revealed a favorable linearity that ranged from 0.04 to 20 μg·mL−1 along with a low limit of detection of 6.85 to 10.19 ng·mL−1. The recovery of the AEDs ranged from 78.7 to 109.2 %, with relative standard deviations below 6.7 %. Using quantum chemistry theory calculations and experimental results analysis, the adsorption mechanism was investigated. It disclosed that the suggested strategy built upon MPBC CD was appropriate for the assessment of AEDs in plasma and expanded the usage of BC as the environmentally favorable matrix for the analysis of biological samples. [ABSTRACT FROM AUTHOR]

• A novel 2D chiral MONs-based CSP used for HPLC. • CSP was prepared by net-wrapped method. • The column shows good enantioselectivity in both NP and RP HPLC. • Racemates failed to be resolved on Chiralpak AD-H but well resolved on the column. In this study, we have synthesised a chiral l -hyp-Ni/Fe@SiO 2 composite as a chiral stationary phase (CSP) for high-performance liquid chromatography (HPLC) for the first time. This was achieved by coating two-dimensional (2D) chiral metal-organic framework nanosheets (MONs) l -hyp-Ni/Fe onto the surface of activated SiO 2 microspheres using the "wrapped in net" method. The separation efficiency of the l -hyp-Ni/Fe chromatographic column was systematically evaluated in normal-phase HPLC (NP-HPLC) and reversed-phase HPLC (RP-HPLC) configurations, employing various racemates as analytes. The findings revealed that 16 chiral compounds were separated using NP-HPLC, and five were separated using RP-HPLC, encompassing alcohols, amines, ketones, esters, alkanes, ethers, amino acids and sulfoxides. Notably, the resolution (Rs) of nine chiral compounds exceeded 1.5, indicating baseline separation. Furthermore, the resolution performance of the l -hyp-Ni/Fe@SiO 2 -packed column was compared with that of Chiralpak AD-H. It was observed that certain enantiomers, which either could not be resolved or were inadequately separated on the Chiralpak AD-H column, attained separation on the 2D chiral MONs column. These findings suggest a complementary relationship between the two columns in racemate separation, with their combined application facilitating the resolution of a broader spectrum of chiral compounds. In addition, baseline separation was achieved for five positional isomers on the l -hyp-Ni/Fe@SiO 2 -packed column. The effects of the analyte mass and column temperature on the resolution were also examined. Moreover, during HPLC analysis, the l -hyp-Ni/Fe columns demonstrated commendable repeatability, stability and reproducibility in enantiomer separation. This research not only advances the utilisation of 2D chiral MONs as CSPs but also expands their applications in the separation sciences. [ABSTRACT FROM AUTHOR]