The most important aspect of sorbent-based approaches is the use of a sustainable, readily available, and cost-effective sorbent material for sample analysis. Biochar is an emerging and prominent sorbent material for various applications in sorbent-based techniques due to its availability, affordability, eco-friendly nature, porosity, pore structure, abundance of aliphatic and aromatic carbon structures, and abundant oxygen-containing functional groups. On the basis of the numerous benefits of biochar, this review discusses why biochar is the preferred sorbent in sorptive-based techniques. In addition, this review provides a brief evaluation of various biochar-based sorptive approaches, including biochar-based solid-phase extraction (SPE)/microextraction (SPME), magnetic SPE/SPME, in-tube SPME, pipette-tip micro SPE, and thin-film microextraction. Furthermore, each section briefly overviews various studies for various sample analyses and applications, including pharmaceuticals, environmental, and food. Most importantly, on the basis of the literature review, biochar is an emerging sorbent material for various sorbent-based techniques that require further investigation for various applications.

A novel dual-wavelength ultrahigh performance liquid chromatography (UHPLC) fingerprint was established, 56 common peaks were confirmed and attributed to the source of the medicinal materials, and 13 chromatographic peaks of them were identified by UHPLC quadrupole time-of-flight (Q-TOF)-MS/MS and UHPLC-UV method. Furthermore, a simple and sensitive HPLC-quadrupole trap (Q-TRAP)-MS/MS was developed for the simultaneous determination of 16 active components with electrospray ionization (ESI) source switching between positive and negative modes in a single run. The above two methods were successfully applied for the quality evaluation of Guanxinjing capsule (GXJC). Finally, statistical analysis including principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares discriminate analysis (OPLS-DA) were applied, and 13 variables with great contribution to different groups of samples were screened. This study not only provides a rapid, accurate, and comprehensive qualitative and quantitative method for quality evaluation of GXJC but it also provides a reference workflow for the other traditional Chinese medicines.

Cannabidiol (CBD) and Δ-tetrahydrocannabinol (THC), the main components of Cannabis sativa plants, can interact with specific cell receptors known as cannabinoid receptors (CBs). The endogenous compounds anandamide (AEA) and 2-arachidonoylglycerol (2-AG) are CB agonists, and, alongside enzymes, they constitute the endocannabinoid system (ECS) and take part in neuromodulation. Several LC-MS/MS methods have been developed to quantify these compounds in biological matrixes, but a fast and simple method that can determine these analytes in plasma samples simultaneously is not available. Here, we propose a disposable pipette extraction technique containing a zirconia-based sorbent (DPX(Zr)) combined with UHPLC-MS/MS analysis to determine CBD, THC, AEA, and 2-AG in plasma samples, simultaneously. The method combines simple protein precipitation (PPT) with a one-step DPX procedure to remove phospholipids, one of the most common endogenous interferents in biological samples. Optimization of the combined PPT-DPX sample preparation method reduced the matrix effect and improved the sensitivity of the analytical method. The validated DPX(Zr)-UHPLC-MS/MS method reported LLOQs of 0.1 ng mL for AEA and 2-AG and 1 ng mL for CBD and THC. The method demonstrated intra- and interassay accuracy and precision of less than 20% for the LLOQ, and less than 15% for the other calibration points. Additionally, no carryover or significant matrix effect was observed. We applied this method to determine AEA, 2-AG, and CBD in plasma samples obtained from obsessive-compulsive disorder patients treated with CBD.

In this study, a commercially available polypropylene homopolymer (H-PP) was blended with blow molding polyethylene (PE) grade via melt mixing using a compounding machine. The resulting blends were subjected to high-temperature size exclusion chromatography (SEC) analysis, coupled with infrared-5 (IR-5), viscometer (VISCO), and multi-angle laser light scattering (MALS) detectors. The molecular weight (MW) and MW distributions were investigated using SEC, and the exact blend compositions were evaluated using C nuclear magnetic resonance. The molecular-level mixing of the PP/PE blend composition was assessed by comparing the theoretical and measured weight-average MW (Mw) values obtained using different SEC detection modes. The measured average Mw values of different PP/PE blends obtained using VISCO and multi-angle light-scattering detection were found to be in close agreement with predicted blend ratios, compared to the conventional SEC technique (IR-5), with percentage errors ranging from -4.53 to -5.99 and 1.57 to 7.65, respectively. The linear relationship between the melt flow rate (MFR) and Mw was studied to assess the molecular-level mixing behavior of the prepared blends using different SEC detection modes. Furthermore, the SEC methodology was extended to other application grades of PE with varying MFRs to verify the blend mixing behavior with H-PP, and the obtained results are discussed.

Organophosphate pesticides can cause long-term neurological damage to humans. There is an urgent need to develop a more sensitive and efficient method for detecting trace amounts of organophosphorus pesticides in orange juice, particularly in the presence of interfering substances. This study developed a dispersive solid-phase extraction (DSPE) method using amorphous UiO-66 (aUiO-66) as an adsorbent for the detection of four organophosphate pesticides (fenthion, profenofos, fensulfothion, and chlorpyrifos) in orange juice. The aUiO-66 was synthesized in a green, direct method within a deep eutectic solvent composed of diethanolamine hydrochloride and acetamide. Its amorphous nature was confirmed through x-ray diffraction (XRD) and thermogravimetric analysis (TGA). Parameters influencing extraction efficiency, including adsorbent dosage, extraction time, eluent type, and volume, were optimized by genetic neural network (GNN). The method demonstrated good linearity (R = 0.9927-0.9981), high recovery (95.35%-110.75%), low limit of detection (0.169-0.214 ng L⁻¹), and precision (intraday RSD = 4.13%-5.44%, interday RSD = 3.28%-4.91%). It was successfully applied to analyze targets in commercially available orange juices, detecting residues within 4.37-36.07 µg L⁻¹. This study's methodological development offers significant guidance for efficient detection of organophosphorus pesticides in food products, potentially facilitating the advancement and application of simpler and more efficient analytical techniques.

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic compounds resulting from incomplete burning of organic materials. This work describes the successful layer-by-layer fabrication of a novel zinc oxide nanocomposite made of zinc oxide nanoparticles, aniline, sodium dodecyl sulfate, and modified multi-walled carbon nanotubes on a stainless steel wire by electrodeposition. The coating and extraction conditions were screened, optimized, and validated using factorial design and central composite design, respectively. The prepared nanocomposites were characterized by the Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray diffraction analysis, and Brunauer-Emmett-Teller techniques. It featured a porous structure, excellent heat stability, and a high extraction capacity. It also adhered well to the steel surface. Extracting PAHs was optimized through experimental design. The optimal conditions obtained for extraction were 60 min, 30%, and 30°C for extraction time, amount of salt, and extraction temperature, respectively. The validated method generally showed a linear range between 0.01 to 1.50 µg/mL with a linearity of (R) of 0.9902-0.9992, limits of detection less than 0.003 µg/mL, limit of quantification lower than 0.010 µg/mL, and relative standard deviation percent less than 45. Recovery values of the analytes in food samples varied between 53.4% and 110.1%. The proposed method was employed in the extraction and determination of some PAHs in some food samples while naphthalene, anthracene, phenanthrene, benzo[a]pyrene, and benz[a]anthracene were detected in certain food samples. Overall, our research suggests a novel nanocomposite as a potential fiber coating that enables high-capacity PAH extraction.

In recent years, despite significant advances in preconcentration and preparation techniques that have led to efficient recovery and accurate measurement of target compounds. There is still a need to develop adsorbents with unique and efficient features such as high pore volume and surface area, reactivity, easy synthesis, low toxicity, and compatibility with the environment, which increase the adsorption capacity and increase extraction efficiency. Semiconductor nanocrystals called quantum dots (QDs) with a size of less than 10 nm are three-dimensional nanoparticles with a spherical, rod, or disc structure that have significant potential in extraction as adsorbents due to their excellent properties such as low toxicity, reactivity, environmental friendliness, and hydrophilic and hydrophobic interactions. One of the most basic issues in the development of adsorbents is to increase the effective surface and, as a result, their extraction efficiency. QDs, having an effective surface much higher than conventional nanomaterials, are a suitable option for extracting target compounds in different environments. This work comprehensively reviews QD-based extraction methods and surface modification strategies of QDs based on functional groups, ligands, and materials from 2013 to 2024. In addition, the applications of QD-based composites for the extraction of organic and inorganic analytes (residues of drugs in human blood and plasma, toxins, pesticides, pollutants from chemical industries, heavy metals, etc.) in different matrices are investigated.

An automated method was developed to simultaneously measure primary amines and short-chain aldehydes emission from foam and rubber samples in one experiment. The technique involved dynamic solid-phase microextraction (SPME) on-fiber derivatization coupled with a flow-cell unit. The parameters of the dynamic SPME on-fiber derivatization method were optimized, including SPME coating, derivatization agents loading temperature, loading time, and dynamic SPME extraction time. The linearity range for the four primary amines and three aldehydes ranged from 0.5 to 100 µg/m and 0.9 to 1050 µg/m, respectively. The amines and aldehydes' quantitation limits (LOQ) were determined as 0.22-0.27 µg/m and 0.10-0.18 µg/m, respectively. Compared to previous methods, this approach is efficient, labor-saving, and allows researchers to concurrently analyze the emission trends of aldehydes and amines in one experiment.

A comprehensive strategy, including spectroscopic, molecular simulation, proteomics, and bioinformatics techniques, was employed to investigate a novel triazole, 5-(4-methoxyphenyl)-1-phenyl-1H-1,2,3-triazole, its interactions with high-abundance blood proteins, and identification of low-abundance proteins. The binding constants and thermodynamic parameters of the triazole to two high-abundance blood globular proteins, human serum albumin, and human immunoglobulin G (HIgG), were obtained by spectroscopic techniques and computational chemistry. The two-dimensional gel electrophoresis in combination with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was employed to isolate and identify differentially expressed low-abundance proteins in human blood serum samples following exposure to the triazole. The results indicated that there is strong binding of the triazole to human serum albumin/HIgG and hydrophobic interaction plays a main role in the system. There were 21 highly expressed proteins identified from blood serum samples intervened by the triazole. By bioinformatics analysis, one of the differential proteins, kininogen-1 protein, was to explore the mechanism of action of 5-(4-methoxyphenyl)-1-phenyl-1H-1,2,3-triazole intervention on the kallikrein-kinin signaling pathways related to HeLa cervical cancer cells. The triazole displayed antiproliferative activity and significantly altered a kallikrein-10 expression, suggesting a possible antitumor mechanism involving the kallikrein-kinin system. These research findings provide scientific insights for further development and application of the 1,2,3-triazole compound. The study highlights the potential of the compound as a multifunctional pharmaceutical agent, particularly in cancer therapies, and lays the foundation for its future clinical applications in targeting drug-protein interactions.

Per- and polyfluoroalkyl substances (PFAS) are a widely used class of synthetic chemicals that pose a significant global environmental and health threat due to their persistent and bioaccumulation toxicity caused by strong C-F bonds in their structures. PFAS usually exist in trace concentrations in environmental water bodies, which poses great challenges for environmental analysis. In this study, environmentally friendly cellulose was modified with polyaniline through in situ oxidative polymerization, and used as the filter paper for solid-phase extracting 23 PFAS in water. Characterization techniques such as scanning electron microscope, Fourier transform infrared spectroscopy, X-ray photoelectron spectrometer, and thermogravimetric analysis indicated the successful synthesis of structurally stable polyaniline-modified cellulose filter paper (PANI/CFP). Then, a high-performance liquid chromatograph-triple quadrupole mass spectrometry determination method was established for 23 PFAS from water using PANI/CFP extraction. The optimal adsorption occurred at a solution pH of 3.0-5.0, and the best elution efficiency can be achieved using methanol with 2% added ammonia water. The adsorption mechanism of 23 PFAS by PANI/CFP can be considered as the result of synergistic effects between physical and chemical adsorption. The recovery rates for 23 PFAS in groundwater, surface water, and wastewater ranged from 65.8% to 105%, with limits of detection and quantification from 0.44 to 36.5 ng/L. After being reused five times, PANI/CFP can still maintain a good extraction recovery rate for PFAS. This study successfully prepared PANI/CFP and established an experimental method flow for its application in the extraction and detection of 23 PFAS in water. The PANI/CFP has the characteristics of stable structure and properties, and easy operation.

Herein, an amino-functionalized covalent organic framework was synthesized and accommodated in the pores of porous hollow fiber. In this context, tetra (4-aminophenyl) porphyrin was synthesized for preparing the desired covalent organic framework as the extracting sorbent and employed for hollow fiber solid-phase microextraction of tebuconazole and propiconazole. With respect to the amino groups of the as-synthesized porphyrin-based covalent organic framework, the extracting device has the ability of establishing a hydrogen bond with the selected model analytes. Under the optimum condition, the linear range of the method for both analytes were estimated in the range of 0.5-200 µg L (the coefficient of determination of 0.9962 for tebuconazole and 0.9990 for propiconazole). The limits of detection of the method for tebuconazole and propiconazole were calculated to 0.02 µg g and 0.03 µg g, respectively. The limits of quantification of the method were also estimated for two analytes equal to 0.07 and 0.08 µg g, respectively. The intra- and inter-day relative standard deviations, which fell between 1.8% and 4.7%, were computed to assess the accuracy of the suggested approach. The proposed method was used for the extraction and determination of tebuconazole and propiconazole in tomato, cucumber, apple, cabbage, and carrot, which the obtained results showed the success of the method in extracting and determining of these analytes from the target samples.

The objective of this study is to develop an HPLC-UV method for the cost-effective and quantitative determination of vitamin D3 in food, even in the presence of vitamin D2, with a specific focus on egg yolk. During method development, the performance of three stationary phases in resolving the peak of vitamin D2 from that of vitamin D3 was investigated. The physicochemical properties of these phases differed particularly in the extent of hydrophobicity and silanophilic activity, including a GraceSmart RP C18 column without silanol endcapping, a Robusta RP C18 column with silanol endcapping, and a Waters Xbridge RP C18 column with ethylene-bridged hybrid (BEH) particle technology. The Xbridge C18 stationary phase exhibited the most favorable performance, leading to an R of 1.6 under the following nonaqueous reversed-phase (NARP) experimental conditions: mobile phase, acetonitrile, methanol, and trifluoroacetic acid in a (99/1/0.1, v/v/v) ratio; column temperature, 15°C. The developed chromatographic method does not require preanalytical purification steps and is also compatible with mass spectrometry. The identity of the vitamin D3 peak observed in the HPLC analysis was verified via GC-MS. The NARP-HPLC-UV method was partially validated, demonstrating satisfactory linearity, precision, accuracy, limit of quantification, and robustness. The HPLC method was then successfully applied to the analysis of real egg yolk samples, revealing average concentrations of vitamin D3 of 4-5 µg/g of wet weight sample.

Monomer compounds from natural products are the major source of active pharmaceutical molecules, which provide great opportunities for discovering of new drugs. However, natural products contain a large number of rather complex compounds. It is difficult to obtain high-purity monomer compounds from complex natural products. Herein, we developed molecularly imprinted macroporous adsorption resins (MIRs-PDA) for the selective adsorption of target monomer compounds from natural products. The response surface methodology was employed to optimize the fabrication parameters. The separation performance of MIRs-PDA for the representative monomer compound rutin was thoroughly studied. We found that MIRs-PDA presented large adsorption capacity (107.82 mg/g), high selectivity (selectivity coefficient was 2.90), good repeatability, and reusability. MIRs-PDA can reach 78.5% equilibrium adsorption capacity in 20 min, showing quick binding kinetic behavior. Furthermore, MIRs-PDA showed good selective and specific adsorption performance for rutin from a representative real sample of Fagopyrum tataricum extract solution. The study of the adsorption mechanism showed that the adsorption of rutin on MIRs-PDA was spontaneous and thermodynamically feasible. The kinetic parameters adapted well to the pseudo-second-order kinetic model, and there existed equivalent binding sites in MIRs-PDA. The MIRs-PDA show promising application prospects for the separation of monomer compounds in natural products.

Tea saponin has garnered tremendous interest for its potential use in surfactant and drug synthesis. This research was designed to develop a technique based on pH-responsive switchable deep eutectic solvents (SDESs) for extracting tea saponins from Camellia oleifera seed meal. SDES synthesized from hexanoic acid and triethanolamine (1:1 molar ratio) offered the optimum extractive performance and the optimal conditions were obtained through single-factor experiments: 30 wt% water content in SDES, solid-liquid ratio of 1:30 g/mL, 60°C extraction temperature, 30 min extraction time, and acid volume of 1500 µL. The extraction yield was 162.14 mg/g after optimization, which increased by 15.65% and 9.47% compared to water and ethanol extraction methods, respectively. After pH adjustment, 98.95% of the tea saponins were recovered in the bottom phase. After precipitation and freeze-drying procedures, the purity of the tea saponin solid was 62.9%.

Evaluating the practical utility of endangered plant species is crucial for their conservation. Nevertheless, numerous endangered plants, including Sinocalycanthus chinensis, lack historical usage data, leading to a paucity of guidance in traditional pharmacological research. This gap impedes their development and potential utilization. Ultra-high-performance liquid chromatography and Orbitrap high-resolution mass spectrometry were employed to analyze the S. chinensis leaves collected at different harvesting times. Then, the metabolites were automatically annotated by a self-built R script in conjunction with characteristic fragment ions, neutral loss filtering, and feature-based molecular networking. By integrating metabolomics with network medicine analysis, the potential usage and optimal harvest times for S. chinensis were unlocked. A total of 305 metabolites were identified, with 66.8% annotated by self-built R script. A progressive increase in metabolite disparities was observed from May to August, followed by a relatively minor distinction from August to October. Notably diverse metabolites were detected in S. chinensis harvested during different periods, implying potential variations in efficacy. Network medicine analysis indicated possible therapeutic implications of S. chinensis for lung cancer, diabetes, bladder cancer, and Alzheimer's disease. Samples collected in May and September demonstrated exceptional efficacy. Harvesting was strategically conducted during these months based on variations in sample characteristics and metabolite content, tailored to their intended applications for dietary or medicinal purposes. This study developed an efficient methodology for investigating metabolites and exploring the potential applications of S. chinensis in food and herbal medicine. Consequently, it provides technical support for the sustainable conservation of endangered plants with limited clinical application experience.

Interest in obstructive sleep apnea is rising due to its neurocognitive and cardiovascular impacts, including systemic hypertension, myocardial infarction, and cerebrovascular events. Obstructive sleep apnea diagnosis can be suggested through symptoms like snoring, daytime sleepiness, and physical signs like increased neck circumference; however, overnight polysomnography is recommended to confirm. Exhaled breath condensate has emerged as a novel, noninvasive technique for biomarker sample collection. It is simple, rapid, repeatable, and suitable for young children and severely ill patients. A direct method using liquid chromatography-mass spectrometry coupled with hydrophilic interaction chromatography was established for quantitative analysis of amino acids in human exhaled breath condensate samples. The separation was performed using XBridge Amide BEH column and a mobile phase of ammonium formate buffer in gradient conditions. The method exhibited a low detection limit (0.08-1.28 ng/mL), good linearity (R between 0.9909 and 0.9987), and high recoveries (93-101.3%) for 21 studied amino acids with interday RSD of 2.1-7.7%. The LC-MS method was verified and applied to determine amino acids in exhaled breath condensate samples from obstructive sleep apnea patients, offering fast, reliable analysis without derivatization as a noninvasive alternative to standard methods.

Imaged capillary isoelectric focusing was successfully applied for separating an in-house synthesized closely related peptide pair, that is, a linear 12-mer (Rp5-L) and its cyclic 15-mer variant (Rp5-C). Rp5-L represents a mimotope, that is, an epitope mimicking peptide, of the CD20 antigen, which is over-expressed in B-cell-related tumors. Peptide identity-including the successful disulfide bond formation in Rp5-C-was confirmed with matrix-assisted laser desorption ionization-time of flight mass spectrometry. The purity of synthesized products was determined by a reversed-phase high-performance liquid chromatographic method with ultraviolet detection. The apparent isoelectric point (pI) of cyclic Rp5-C and Rp5-L was 5.99 and 6.47, respectively. An appropriate combination of carrier ampholytes allowed for their baseline separation with an analysis time of <20 min. Method validation was done for the synthesized peptides and three flanking pI markers covering, for example, repeatability and intermediate precision. Calibrations on different days resulted in identical slopes for Rp5-L and Rp5-C, respectively, as statistically confirmed by Welch's t-test and pooled t-test over 8 days. The calibration data of mimotopes and pI markers were evaluated for outliers, normality, homoscedasticity, and autocorrelation with complementary statistical procedures, which identified an otherwise unnoticed outlier for a pI marker. The linearity of calibration for Rp5-L, Rp5-C, and the pI markers was tested with Mandel's fitting test and lack-of-fit test. For Rp5-L and Rp5-C, the calculated limits of detection and limits of quantification were ≤0.31 and ≤0.96 µmol/L, respectively.

In the context of the energy transition, European countries pursue the common goal of increasing the share of renewable gases (from anaerobic digestion, pyrogasification, and hydrothermal gasification for instance) in the gas mix. Although produced gases are mainly composed of methane after upgrading, impurities of various natures and quantities may also be present in the produced raw gases and still after upgrading, including volatile organic compounds (VOCs) at trace levels that may have an impact on different stages of the gas chain even at low concentrations. These new renewable and/or low-carbon gases imply the need to develop new analytical tools to deeply characterize them, and thus fully manage their integration into the gas value chain. In this study focused on VOC analysis, a sampling approach using pre-concentration on an adsorbent phase was developed for gas sampling to ensure rapid collection, requiring only a small volume (≈ 100 mL). Traces were then analyzed by thermal desorption hyphenated to a comprehensive two-dimensional gas chromatography time-of-flight mass spectrometer. After identifying the compounds, a semi-quantification method was developed to provide an estimation of the concentration of VOCs for each chemical family. The method was first developed on a biomethane sample before being successfully applied to a raw gas produced by hydrothermal gasification, in which around 250 compounds were detected at a trace level (total concentration equivalent at 200 µg/L).

This study developed a stability-indicating HPLC-DAD method for quantifying haloperidol in oral solution using analytical quality-by-design principles. Haloperidol stability was tested under acidic, alkaline, oxidative, and photolytic stress conditions. The analytical quality-by-design approach began by defining the analytical target profile and identifying critical material attributes and critical method parameters via risk analysis. Factorial and Box-Behnken designs, conducted in Design Expert 13, were used to select critical method parameters and determine the method operable design region. The oral solution degraded significantly under acidic and alkaline conditions. Continuous critical method parameters such as mobile phase flow rate, gradient slope, column temperature, and pH were optimized. A quadratic Box-Behnken design with critical method attributes was applied and validated, resulting in robust regression models with significant p-values (> 0.05), absence of lack-of-fit (p-values < 0.05), and R-adjusted > 0.85. The method proved selective, accurate, and precise within the method operable design range. Normal operating conditions (NOCs) were established using a Waters Symmetry C18 column with a 100-mM formate buffer (pH 3.8) and acetonitrile, with a gradient profile and detection at 246 nm. The operational region included flow rates between 1.2 and 1.35 mL/min (NOC = 1.3 mL/min), temperatures of 8°C-20°C (NOC = 15°C), and mobile phase pH variations from 3.3 to 4.3 (NOC = 3.8). The analytical quality-by-design-based method was robust and effective for stability monitoring, reducing subjectivity while maximizing reliability.

Oligonucleotides (ONs) are an increasingly popular category of molecules in the pharmaceutical landscape, particularly attractive for the treatment of genetic and rare diseases. However, analyzing these molecules presents significant challenges, due to their highly hydrophilic nature, multiple negative charges, and the presence of closely related impurities resulting from the complex solid-phase synthesis process. Ion pairing reverse-phase liquid chromatography (IP-RPLC) is the preferred technique for ONs analysis but is not ideal for mass spectrometry (MS) coupling. Consequently, there is a growing interest in exploring alternative strategies with hydrophilic interaction chromatography (HILIC) emerging as one of the most promising options. As HILIC is not yet fully established for the analysis of ONs, we have prepared this protocol paper to facilitate entry into this field. It not only provides best practices, opportunities, and potential advantages but also caveats and other important considerations for using HILIC to characterize ONs. The paper addresses the selection of stationary and mobile phases, optimization of gradient conditions, MS coupling, and key aspects to consider when manipulating ON samples. We hope this protocol will help establish HILIC as a more universal solution for ONs analysis.