J Chromatogr A [JOURNAL]
Sun
200 papers
Impurity profiling of lipid-conjugated oligonucleotides using reversed-phase with and without ion-pair reagents and hydrophilic interaction liquid chromatography.
Bui QD, Kesselaers E, Noten B … +2 more , Deschrijver T, Eeltink S
J Chromatogr A · 2026 Jun · PMID 42401125 · Publisher ↗
Lipid-oligonucleotide conjugates (LONs) represent a next-generation class of biopharmaceuticals that couple nucleic-acid specificity with lipid-mediated delivery, enabling superior membrane affinity and cellular uptake,...
Lipid-oligonucleotide conjugates (LONs) represent a next-generation class of biopharmaceuticals that couple nucleic-acid specificity with lipid-mediated delivery, enabling superior membrane affinity and cellular uptake, for highly targeted therapeutic action. Lipid type and conjugation position strongly influence hydrophobicity, retention, and interaction strength from the exposure of the lipid moiety, thereby affecting the chromatographic behavior of impurities such as shortmers and diastereomers. In this study, we systematically investigated the performance of different chromatographic modes, reversed-phase LC (with and without ion-pairing agents) and hydrophilic interaction LC (HILIC), and assessed the influence of mobile-phase additives on the retention behavior of both single- and double-stranded LONs. RPLC and IP-RPLC proved superior to HILIC for impurity profiling, offering higher separation resolution and MS compatibility. In contrast to naked ONs, LON retention did not follow an on-off mechanism in (IP-)RPLC mode. Moreover, LONs displayed the opposite retention order. A novel metric was developed to account for the hydrophobic contributions of both the oligonucleotide backbone and lipid conjugation, demonstrating a strong correlation with experimentally observed retention behavior in RPLC. High resolving power was achieved for diastereomeric impurity profiling of internally lipid-modified oligonucleotide (iLON) duplexes using a C column in RPLC mode, revealing that the extent of phosphorothioate modification suppression depends strongly on both the lipid type and its conjugation position. The resolving power of RPLC was demonstrated by separating >30 of the theoretical 64 diastereomers present in a siRNA sample.
Preparation of magnetic zwitterionic covalent organic frameworks for rapid simultaneous extraction of hydrophilic and hydrophobic organophosphates from environmental waters coupled with UHPLC-MS/MS determination.
Wang S, Ma J, Xing Z … +3 more , Wu Y, Wang X, Chen L
J Chromatogr A · 2026 Jun · PMID 42401124 · Publisher ↗
Organophosphate esters (OPEs) are a class of additive flame retardants that exhibit persistence, toxicity, and bioaccumulative potential. These compounds can persist in environmental media for extended periods and may en...
Organophosphate esters (OPEs) are a class of additive flame retardants that exhibit persistence, toxicity, and bioaccumulative potential. These compounds can persist in environmental media for extended periods and may enter the human body through multiple exposure pathways, thereby posing significant risks to human health. In this research, a novel analytical method for the simultaneous determination of trace amounts of 14 hydrophilic and hydrophobic OPEs (log Kow=1.53-8.90) in water samples is developed by using magnetic zwitterionic covalent organic framework (COF) based on magnetic solid-phase extraction prior to UHPLC-MS/MS analysis. Inspired by the amphiphilic molecular architecture of phospholipid bilayers, we rationally designed and synthesized a phosphoester-functionalized COF anchored onto magnetite nanoparticles (FeO@P-ZCOF). The effects of various extraction parameters, including FeO@P-ZCOF dosage, solution pH, extraction time, eluent type, elution duration, and ionic strength, on the extraction efficiency of the target analytes were systematically investigated. Under the optimized extraction conditions, 14 OPEs were successfully pretreated within only 6 min. The limits of detection (LOD, S/N = 3) for wastewater, reservoir water and tap water range from 0.01 to 1.50 ng/L, 0.01 to 1.00 ng/L and 0.01 to 2.00 ng/L, respectively. The method presents some merits such as quick and simple sample pretreatment procedure, and being able to simultaneously determine the hydrophilic and hydrophobic properties of OPEs. The method was successfully used to detect OPEs in the effluent and influent of 6 sewage treatment plants.
Analysis of organic and inorganic acids in biomass pyrolysis process samples by ion chromatography-mass spectrometry.
Alwis S, Lebanov L, Davies NW … +3 more , Richardson DE, Paull B, Sanz Rodriguez E
J Chromatogr A · 2026 Jun · PMID 42401123 · Publisher ↗
Biomass pyrolysis is a sustainable process that converts organic matter into value‑added products such as biochar, bio‑oil, and syngas. The composition of pyrolysis products varies widely depending on biomass type, age,...
Biomass pyrolysis is a sustainable process that converts organic matter into value‑added products such as biochar, bio‑oil, and syngas. The composition of pyrolysis products varies widely depending on biomass type, age, moisture content, and operating conditions. Monitoring compositional changes during pyrolysis is therefore essential for improving product quality, maintaining process efficiency, and enabling by‑product valorisation. A new ion chromatography-mass spectrometry (IC‑MS) method is presented for the quantitative determination of organic and inorganic acids released during biomass pyrolysis, namely acetic, formic, sulfuric, oxalic, and phosphoric acids. Sample preparation involved simple dilution and filtration, with chromatographic separation achieved using an IonPac AS24 column within a 30 min run time. Quantification was carried out by ESI-MS using time-Selected Ion Monitoring (t-SIM) and the standard addition method (SAM). Suppressed conductivity detection provided complementary monitoring of overall ionic species, while Full Scan acquisition supported broader screening. Instrumental limits of detection ranged from 0.2 to 3.4 ng mL⁻¹ across all analytes. Intra‑day and inter‑day repeatability was better than 12 % for all analytes, except oxalic acid, which showed inter‑day variability below 20 %. The method was applied to analyse 215 samples collected from two commercial pyrolysis process sampling points over an eight‑month operating period, providing detailed insight into temporal and spatial changes in acid profiles during this processing period. Acetic and formic acids were identified as markers for by‑product levels, while elevated sulfuric acid concentration was associated with decreased main product yield. This study demonstrates that the developed IC‑MS method is a rapid, robust, and industry‑ready tool for process monitoring, optimisation, and product quality assessment.
Separation and enrichment of phages at the interface between two phases in a green solvent-based sugaring-out extraction system.
Yang R, Dong Y, Hou H … +2 more , Yin J, Xiu Z
J Chromatogr A · 2026 Jun · PMID 42391995 · Publisher ↗
The advantages of using phages as an alternative to antibiotics are evident in the response to the growing multidrug resistance of microorganisms. Green and efficient extraction methods for phages have attracted consider...
The advantages of using phages as an alternative to antibiotics are evident in the response to the growing multidrug resistance of microorganisms. Green and efficient extraction methods for phages have attracted considerable attention for large-scale production. In this study, a novel sugaring-out extraction (SOE) system was developed to isolate and purify Klebsiella pneumoniae phage from the crude phage lysate. Phages were preferentially enriched in a middle phase formed between the triethyl citrate-rich top phase and the glucose-rich bottom phase. The SOE system composed of triethyl citrate and glucose was optimized based on phage recovery and impurity removal. The distribution behavior of the phages, phase separation, and extraction kinetics were investigated. The optimized system achieved a middle-phase recovery of 82.4 ± 1.6% for phage phiKpS2, and most proteins (91.8 ± 0.9%), cells (96.2 ± 1.5%), and endotoxins (81.1 ± 1.3%) were effectively removed using a SOE system consisting of 28% (w/w) glucose and 30% (w/w) triethyl citrate. The phage concentration factor reached 46.7-fold, and the separation factors of phage relative to proteins, cells, and endotoxins were 149.7, 109.6, and 5.4, respectively. Furthermore, the conductivity measurements indicated that the SOE gradually shifted phage phiKpS2 from the bottom phase to the middle phase as the phase volume ratio increased. The extraction kinetics showed that the partitioning behavior could be completed within 40 min without centrifugation. Finally, this SOE system also proved applicable for the isolation and purification of phages λ, phiSM29, and phiSM30, which were successfully enriched in the middle phase. Understanding the mechanism of the SOE process is important for its further application and industrial scale-up in phage purification.
Advances and perspectives in Oligo(dT) Affinity chromatography for mRNA capture: Resins, ligands and process intensification.
Tian X, Jin J, Zhu X … +4 more , Wang Y, Qiu Y, Qiao L, Zhao L
J Chromatogr A · 2026 Jun · PMID 42391994 · Publisher ↗
With the rapid development of the mRNA pharmaceutical industry, Oligo(dT) chromatography, as a core step in mRNA separation and purification, has garnered increasing attention from both the industry and researchers. This...
With the rapid development of the mRNA pharmaceutical industry, Oligo(dT) chromatography, as a core step in mRNA separation and purification, has garnered increasing attention from both the industry and researchers. This article begins with the fundamental principles of mRNA affinity chromatography, analyzes the advantages and disadvantages of two typical affinity techniques, and highlights the sufficiency of Oligo(dT) chromatography as a platform technology. Aiming to the poor performance of the Oligo(dT) chromatography, the article reviews the main methods and mechanisms for enhancing its performance from three perspectives, resin structure, ligand structure, and process intensification. It also highlights the factors influencing the performance of Oligo(dT) chromatography and the challenges associated with these methods. The article provides an outlook on the future development directions of Oligo(dT) chromatography, offering insights for the advancement of next-generation Oligo(dT) chromatography resins and processes.
Ion chromatography: Current strengths, key limitations, and future trends.
Michalski R, Kończyk J
J Chromatogr A · 2026 Jun · PMID 42391993 · Publisher ↗
Ion chromatography, developed over the past 50 years, has significantly revolutionized analytical chemistry, going far beyond the classical determination of simple anions and cations. During this time, the separation tec...
Ion chromatography, developed over the past 50 years, has significantly revolutionized analytical chemistry, going far beyond the classical determination of simple anions and cations. During this time, the separation technique has undergone a profound evolution in both instrumentation, and scope of applications. Its primary field of applications remain water and wastewater monitoring. However, over the past decade, there has been a dynamic expansion of its applications in environmental, food, pharmaceutical, clinical, and different industrial samples. This paper discusses the key advantages and limitations of ion chromatography and provides an overview of the most significant achievements of the past 10 years in terms of new application areas, technological development, and the implementation of updated and new international standards based on ion chromatography. Based on this, current trends and prospects for the further development of this technique as a key tool for modern analysis in various fields of science and industry are outlined.
Stereo-sensitive modelling of gas chromatographic retention indices of mono-cycloalkanes in jet fuel range.
Lüdtke H, Pütz F, Grams S … +6 more , Gröger T, Giocastro B, Bauder U, Köhler M, Huber A, Oßwald P
J Chromatogr A · 2026 Jun · PMID 42385659 · Publisher ↗
Accurate assessment of novel aviation fuels requires detailed insight about structural differences relative to conventional jet fuels. To support compositional characterization, retention behavior of cycloalkanes needs t...
Accurate assessment of novel aviation fuels requires detailed insight about structural differences relative to conventional jet fuels. To support compositional characterization, retention behavior of cycloalkanes needs to be investigated further to evaluate fuels on an isomeric level. Current available literature models for the prediction of saturated cyclic retention indices (RI) are limited in carbon range or by neglection of stereo isomeric effects. This study addresses the challenge of comprehensive RI prediction of mono-cycloalkanes by utilizing available retention data from the NIST23 database and the combination of descriptors from PaDEL, Mordred and RDKit. Multiple model approaches (extreme gradient boosting, multi-layer perceptron regression, support vector regression and ridge regression) were tested via repeated k-fold cross-validation to evaluate robustness and reliability in prediction. As the available literature data was skewed, model tests were run for data up to carbon number C13 and the whole dataset to C20 individually. Cross-validation results showed the best error metrics for the validation sets with ridge regression (e.g. C13-models mean absolute error: MAE = 11.01 ± 1.32 RI; C20-model MAE = 13.68 ± 1.67 RI). Correct stereo sensitive retention of diastereomeric structures was achieved in 78 %, with cis/trans differentiation being the best represented stereo effect. These advancements will enable a more detailed characterization of compositional differences and will subsequently enhance evaluation of novel fuel production paths.
Approaches to using retention indices with coupled column pressure tuning in gas chromatography.
Sharif KM, Chin ST, Marriott PJ
J Chromatogr A · 2026 Jun · PMID 42378915 · Publisher ↗
Pressure tuning (PT) of a coupled column ensemble in gas chromatography (GC) changes the retention time of analytes by altering the contribution of each column in the dual column system. This study investigates the effec...
Pressure tuning (PT) of a coupled column ensemble in gas chromatography (GC) changes the retention time of analytes by altering the contribution of each column in the dual column system. This study investigates the effect of PT between the two columns on calculation of compound retention indices (RI), and proposes an approach to align RI data with values reported in a database library. The study first describes a model to predict the relative coupled column contribution to separation (φ) according to the PT process. The first column contribution could be tuned from 0.20 to 0.97 φ by altering the mid-point pressure (p), which implies the property of the two-column ensemble can range from behaving similar to the first column, or to the second column, or some intermediate property depending simply on the junction pressure. The second part establishes a relationship between φ and oven temperature by using multivariate analysis based on isothermal experimental data, showing a significant change of φ in a T programmed GC analysis. The deviation for PT RI from single column RI values is related to two reasons, (1) variable retention on the coupled column ensemble, and (2) contribution of each column arising from PT. RI values can be tuned according to the mid-point pressure setting; for example, γ-terpinene, d-limonene and o-cymene had RI value changes of 3, 8 and 16 I unit, respectively simply by changing p by 1 psi. A correction factor may be calculated using chi-square fitting to predict single column RI data from experimental PT coupled column RI values at a particular φ, allowing the PT system to match the analyte RI with library database values.
MOF-supported surface-imprinted polymer for hazard governance of aristolochic acids in herbal matrices: A safety-control strategy supported by multiscale simulations.
Li H, Wang S, Ma J … +5 more , He Z, Jia Y, Sun W, Han X, Li X
J Chromatogr A · 2026 Jun · PMID 42378914 · Publisher ↗
Aristolochic acids are highly toxic compounds found in certain herbal medicines, posing significant safety risks. To address this, a UiO-66-NH(Zr)-supported surface molecularly imprinted polymer (SMIP) was developed, usi...
Aristolochic acids are highly toxic compounds found in certain herbal medicines, posing significant safety risks. To address this, a UiO-66-NH(Zr)-supported surface molecularly imprinted polymer (SMIP) was developed, using indomethacin (IND) as a pseudo-template to create selective binding sites for aristolochic acid I (AA-I). Characterizations confirmed the formation of a thin imprinted layer and the successful removal of the pseudo-template. Adsorption fitting confirmed that physical monolayer adsorption predominated, with both imprinted and non-imprinted adsorption sites present. The SMIP exhibited a maximum adsorption capacity of 9.02 mg·g and an imprinting factor of 2.77. Selectivity tests demonstrated a pronounced preference for AA-I, with relative selectivity factors of 4.19 (vs p-nitrophenol) and 3.82 (vs tanshinone IIA). After five adsorption-desorption cycles, the adsorption efficiency remained above 94.15%, indicating good stability and reusability. The SMIP enabled effective recognition and adsorption of spiked AA-I from complex Caulis Clematidis Armandii extracts. Density functional theory calculations revealed that hydrogen bonding and van der Waals interactions played a dominant role in both imprinting and adsorption processes. Molecular dynamics simulations further visualized the solvent-dependent adsorption and elution behaviors of AA-I. Fukui mapping identified acceptor-rich carbonyl/nitro oxygen sites in IND/AA-I, reinforcing the bidirectional hydrogen-bonding motif and IND's mimicry of AA-I. In summary, this work proposes a reusable, mechanism-guided imprinting strategy that maintains high selectivity for materials while utilizing green pseudo-templates. It provides a useful reference for the selective monitoring and removal of toxic components and contaminants in complex herbal and related matrices.
Portable cold-assisted head-space solid-phase microextraction coupled with GC-MS/MS for sensitive determination of trace polychlorinated naphthalenes in water.
Han Y, Wang J, Liu W … +4 more , Li P, Zhang M, Jin X, Wang Z
J Chromatogr A · 2026 Jun · PMID 42372584 · Publisher ↗
A cold-assisted headspace solid-phase microextraction (CA-HS-SPME) method combined with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of eight polychlorinated naphthalene (PCN) congener...
A cold-assisted headspace solid-phase microextraction (CA-HS-SPME) method combined with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of eight polychlorinated naphthalene (PCN) congeners in water sample. In the CA-HS-SPME setup, frozen gel served as the refrigerant and copper tube as the thermal conductor to cool the polydimethylsiloxane (PDMS) fiber during extraction, thereby enhancing extraction efficiency. The main experimental variables affecting the extraction performance, including temperature, extraction time, and salt concentration, were systematically optimized. Under the optimized conditions, the method exhibited good linearity over the range of 0.1/0.5/1-500 pg/mL, with the correlation coefficient (r) values ≥ 0.9962. The enrichment factors for the PCNs ranged from 955 to 4299, while the limits of detection and quantification were 0.02-0.28 pg/mL and 0.07-0.92 pg/mL, respectively. The intra-day and inter-day precisions (n = 6), expressed as the relative standard deviations, were 10.8%-16.3% and 12.2%-17.8%, respectively. The recoveries obtained from fortified water samples ranged from 90.7% to 117.8%. The proposed method is sensitive, simple, solvent-free, and provides an effective approach for the determination of trace PCNs in water.
Characterization of phosphorous impurities originating from the synthesis of Sarin.
Mörén L, Lindén P, Engqvist M … +5 more , Larsson A, Jonsson S, Åstot C, Norlin R, Holmgren KH
J Chromatogr A · 2026 Jun · PMID 42372583 · Publisher ↗
Forensic chemical analysis aims not only to confirm the presence of an illicit chemical agent but also to determine its origin, synthesis route, and production conditions to bring evidence for a criminal investigation. I...
Forensic chemical analysis aims not only to confirm the presence of an illicit chemical agent but also to determine its origin, synthesis route, and production conditions to bring evidence for a criminal investigation. In the production of organophosphorus-nerve agents and their precursors, phosphorous-containing species arise at different stages of synthesis and reflect specific reaction conditions. However, current methods for analysing methylphosphonic dichloride (DC) (precursor of sarin) impurities are often limited by the high reactivity and low concentrations of key phosphorus-containing species, which frequently evade detection using standard analytical protocols. Reactive phosphorus-containing impurities within the nerve agent precursor DC were investigated and we demonstrated how these species account for impurity profiles and are observed throughout the synthesis chain of sarin. A set of twelve sarin samples, including crude and distilled materials and precursors from each synthetic step, was analysed using GC- and LC-HRMS, NMR spectroscopy and GC-FPD, with particular emphasis on phosphorus-containing compounds. Many impurities in final products are shown to be reaction products of impurities already present in DC, enabling chemical linkages between starting materials, intermediates, and end products. This work enhances forensic attribution through impurity profiling and introduces butanethiol derivatisation as a novel tool for the detection and interpretation of reactive phosphorus-containing impurities. By converting highly reactive species to more stable analytes, this derivatisation method enables the detection of previously elusive impurities, providing critical information for the forensic attribution of chemical weapons production.
Extraction and chromatographic purification of purpurin: A scalable approach using modified dry column vacuum chromatography.
Bhowmik DD, Jadhao M, Beldar VG
J Chromatogr A · 2026 Jun · PMID 42365794 · Publisher ↗
Purpurin, a trihydroxy anthraquinone derivative, is an important bioactive compound isolated from Rubia cordifolia roots and recognize for its versatile pharmacological activities. The principal objective of the present...
Purpurin, a trihydroxy anthraquinone derivative, is an important bioactive compound isolated from Rubia cordifolia roots and recognize for its versatile pharmacological activities. The principal objective of the present study was to develop a rapid, reproducible, and scalable method for well organized extraction and purification of purpurin from Rubia cordifolia roots. Extraction was initiated via acid hydrolysis using optimized concentrations of hydrochloric acid as well as ferric chloride, followed by solvent extraction with chloroform. Including numerous experimental trial conditions, the combination of 20% HCl and 20% FeCl₃ under reflux yielded a dry crude extract of crude anthraquinones with a significantly enhanced yield of 1.76%. To attain high-purity isolation of purpurin, an indigenously developed dry column vacuum chromatography (DCVC) system was employed. Crude purpurin (1 g) was subjected to DCVC by utilizing silica gel as the stationary phase and a polarity gradient of hexane and ethyl acetate as the mobile phase. The DCVC method optimization involved variations in column internal diameter and silica bed size/depth. The most operational set up of DCVC includes a 6.5 cm diameter DCVC column with 8 cm silica bed size which achieved a product recovery yield of 58 - 62% and a purity range of 95-98%, as established by TLC and UHPLC analysis. The developed DCVC method proved excellent reproducibility and scalability across experimental trials. This integrated approach proposes a time-efficient and solvent-economical strategy for the preparative-scale isolation of purpurin with high purity.
Development and validation of a modified QuEChERS-LC-MS/MS method for multi-class pesticide residue analysis in soils from pesticide production sites.
Zhang D, Liu M, Ma F … +6 more , Mo X, Xiang Y, Li X, Chen X, Jiang R, Gu Q
J Chromatogr A · 2026 Jun · PMID 42364516 · Publisher ↗
Soils at pesticide production sites typically exhibit complex mixed contamination profiles characterized by high residual concentrations and strong persistence due to the long-term, iterative production of multiple pesti...
Soils at pesticide production sites typically exhibit complex mixed contamination profiles characterized by high residual concentrations and strong persistence due to the long-term, iterative production of multiple pesticide classes. However, research on multi-residue analytical methods currently produced mainstream pesticides in such complex matrices remains scarce. In this study, a multi-residue analytical method for 13 classes of pesticides (comprising 55 compounds, -0.7 ≤ logP ≤ 7.3) in soils from pesticide production sites was developed and validated based on a modified QuEChERS approach coupled with liquid chromatography-tandem triple quadrupole mass spectrometry (LC-MS/MS) detection. Suitable extraction and cleanup conditions were screened through a combination of single-factor optimization and interaction experiments, and the performance of the method was evaluated in comparison with a QuEChERS method developed for conventional soil matrices. The results demonstrated that the method achieved satisfactory recoveries for 53 target pesticides in both quartz sand and site soils, with values ranging from 70% to 120% and good precision (RSDs < 20%). The limits of quantification (LOQs) ranged from 0.5 to 5 μg/kg, and the calibration curves showed good linearity (R > 0.991). Fortified-recovery testing of 21 site-soil samples from seven provinces in China showed reliable determination of 50-54 pesticides. Furthermore, the method was successfully applied to 22 soil samples collected from three pesticide production sites with different production histories, identifying 35 target pesticides. It maintained reliable quantitative performance even under high-residue conditions (1.23 × 10 μg/kg). This study provides a reliable analytical basis for the investigation and risk assessment of mixed pesticide contamination in soils from pesticide production sites.
Acid-treated ZIF-67-derived porous carbon based QuEChERS coupled with LC-MS/MS for sensitive determination of multi-pesticide residues.
Chen M, Wan L, Yu S … +6 more , Chen L, Yu J, Wang X, Nie C, Xie F, Zhang W
J Chromatogr A · 2026 Jun · PMID 42364515 · Publisher ↗
Porous carbon-based QuEChERS purification material (CZIFA) was synthesized through a straightforward calcination and acid treatment process using Zeolitic Imidazolate Framework-67 (ZIF-67) as the precursor. The abundant...
Porous carbon-based QuEChERS purification material (CZIFA) was synthesized through a straightforward calcination and acid treatment process using Zeolitic Imidazolate Framework-67 (ZIF-67) as the precursor. The abundant adsorption sites and excellent clean-up capability of CZIFA resulting from acid treatment were confirmed through a series of characterization and performance evaluations. Combined with LC-MS/MS, a modified QuEChERS method using CZIFA as the adsorbent was developed for the simultaneous detection of 48 pesticide residues in tobacco. Under optimized conditions, the established method achieved low limits of detection (0.02-9.92 μg/kg), wide linear ranges (2-200 μg/L), and satisfactory precision. The average recoveries of the method were in the range of 80.1-119.7% with the relative standard deviations (RSDs) of <9.5%. This study provides a novel and efficient functionalized material for analyzing pesticide residues in complex matrices. Especially, it expands the application of ZIF-derived carbon materials in food safety detection.
Polybenzimidazole-based magnetic solid-phase extraction coupled with gas chromatography-mass spectrometry for the determination of triazine herbicides in environmental waters.
Li Y, Yan X, Tian J … +2 more , Wu D, Jiang D
J Chromatogr A · 2026 Jun · PMID 42364514 · Publisher ↗
A novel FeO/polybenzimidazole (FeO/PBI) nanocomposite was synthesized by a facile phase inversion method and used as a magnetic solid-phase extraction (MSPE) adsorbent for the determination of eight triazine herbicides (...
A novel FeO/polybenzimidazole (FeO/PBI) nanocomposite was synthesized by a facile phase inversion method and used as a magnetic solid-phase extraction (MSPE) adsorbent for the determination of eight triazine herbicides (THs) in environmental waters prior to gas chromatography-mass spectrometry (GC-MS). The FeO/PBI nanocomposite combined the strong magnetism of FeO with the abundant functional groups and good chemical stability of PBI, providing multiple interaction sites for THs. Characterization results demonstrated the high magnetic strength (40.8 emu/g) and large specific surface area (90.5 m/g) of the FeO/PBI nanocomposite. Key MSPE parameters, including the amount of adsorbent, extraction and desorption times, ionic strength, sample pH, desorption solvent type and volume, were systematically optimized to achieve efficient extraction and desorption. Under optimal conditions, the proposed MSPE/GC-MS method based on the FeO/PBI nanocomposite exhibited excellent analytical performance for eight THs, with wide linear ranges (0.1-100, 0.2-100, or 0.5-100 μg/L), low limits of detection (0.040-0.182 μg/L) and limits of quantification (0.133-0.606 μg/L), and satisfactory precision (relative standard deviations (RSDs) of 0.5-11.7%, n = 3). With 10 mg of adsorbent, extraction recoveries of the target THs ranged from 73.1% to 86.9% within 5 min. The FeO/PBI nanocomposite showed good reusability, maintaining nearly constant peak areas over at least 10 consecutive extraction-desorption cycles, indicating high stability in high‑salinity matrix and organic solvents. The applicability of the method was further demonstrated by the analysis of THs in tap water, river water, and pond water samples, yielding relative recoveries of 80.8-118.8% with RSDs of 0.1-8.7%. These results demonstrate that the FeO/PBI nanocomposite is a promising adsorbent for MSPE, and the developed MSPE/GC-MS method is suitable for the reliable determination of trace THs in environmental waters.
Multi-residue analysis of systemic insecticides and their transformation products in environmental matrixes: Method development and application.
Xiong J, Wang Y, Wu Y … +11 more , Wu Z, Zhao Y, Wen Y, Liu Y, Zeng S, Liu M, Xing X, Zhang J, Qi S, Jones KC, Chen W
J Chromatogr A · 2026 Jun · PMID 42364513 · Publisher ↗
A robust and sensitive analytical method was developed and validated for simultaneous determination of 38 systemic insecticides and their transformation products (TPs), including neonicotinoid insecticides (NNIs), fipron...
A robust and sensitive analytical method was developed and validated for simultaneous determination of 38 systemic insecticides and their transformation products (TPs), including neonicotinoid insecticides (NNIs), fipronil (FIP) and their typical TPs in six environmental matrices, namely surface water, groundwater, wastewater, soil, sediment and sludge. The method integrated optimized extraction procedures for solid samples and solid-phase extraction (SPE) cleanup/enrichment with liquid chromatography-tandem mass spectrometry (LC-MS/MS), aiming to support the investigation of the occurrence and environmental behaviour of these systemic insecticides and their TPs in multimedia environment. The pre-treatment including the selection of SPE cartridges, sample pH, extraction reagents and procedures were optimized, and acceptable recoveries (> 60% for 35 target compounds), low method detection limits (surface water and groundwater: 0.003-0.319 ng/L, wastewater: 0.007-0.637 ng/L, soil and sediment: 0.42-82.1 ng/kg, and sludge: 0.38-205 ng/kg) and excellent precision (intra-day repeatability: RSDs < 5% for all analytes; inter-day reproducibility: RSDs < 10% for > 90% of analytes) were achieved. Optimised methods were applied to analyse NNIs, FIP and TPs in surface water, sediment and soil from the Dawen River Basin, groundwater in karst springs from Zigui, and wastewater and sludge from wastewater treatment plants in Wuhan, China. The results revealed that TPs had comparable or even higher concentrations and detection frequencies than their parents in all tested matrices, with the concentrations of certain NNI-TPs (e.g., Desnitro-imidacloprid: 2368 ng/L and Thiamethoxam-urea: 1882 ng/L) being among the highest reported in surface water worldwide. The developed method provides a tool to comprehensively investigate NNIs, FIP and their TPs in common environmental matrices, and the preliminary findings in the characterization of environmental samples emphasise the importance of incorporating TPs into investigations in future environmental studies.
Cell separation coupled with surface-enhanced Raman spectroscopy: A critical review.
Jafari Ghahfarokhi N, Kim M, Bayareh M
J Chromatogr A · 2026 Jun · PMID 42364512 · Publisher ↗
The integration of cell separation technologies with surface-enhanced Raman spectroscopy (SERS) offers a powerful approach for sensitive molecular diagnostics. This review critically evaluates label-dependent (FACS, MACS...
The integration of cell separation technologies with surface-enhanced Raman spectroscopy (SERS) offers a powerful approach for sensitive molecular diagnostics. This review critically evaluates label-dependent (FACS, MACS) and label-free (DEP, acoustic, magnetic, inertial, DLD) separation methods coupled with SERS detection for cancer diagnosis, pathogen detection, and environmental monitoring. On-chip integration provides continuous operation, reduced sample loss, and real-time monitoring, while off-chip approaches allow independent optimization of separation chemistry and SERS substrates. Hybrid cascaded architectures combining multiple separation mechanisms achieve both high throughput and high specificity. Key challenges include substrate standardization, long-term stability, and limited clinical validation on large cohorts. Machine learning integration and portable Raman spectrometers are accelerating translation to point-of-care settings. This review provides a roadmap for developing robust, reproducible, and clinically deployable SERS-based diagnostic platforms.
Chromatographic peak shape from a stochastic-diffusive model with multiple retention mechanisms: Analytic time-domain expression and derivatives.
Sánchez HR
J Chromatogr A · 2026 Jun · PMID 42361693 · Publisher ↗
A time-domain analytic expression for chromatographic peak shapes is derived within a stochastic-diffusive framework that incorporates axial diffusion (molecular and multipath/eddy), finite initial spatial variance, a re...
A time-domain analytic expression for chromatographic peak shapes is derived within a stochastic-diffusive framework that incorporates axial diffusion (molecular and multipath/eddy), finite initial spatial variance, a retention mechanism characterized by a high rate of short-duration events, and an arbitrary number of independent slow retention mechanisms, each characterized by its own rate of infrequent, long-duration events. A highly efficient evaluation scheme is derived for this expression. In the single-slow-mechanism case, it is two to four orders of magnitude faster than the previously available analytic route. Analytical derivatives with respect to all model parameters are also obtained, and each can be evaluated at computational cost comparable to that of the peak-shape expression. Illustrative fits to three literature peaks yielded full-profile RMSE values lower than those obtained with the exponentially modified Gaussian (EMG), a well-established phenomenological peak-shape function included only to place the residual magnitudes in context, with minima ranging from 0.03 to 0.14 percent of peak height, compared with 0.43 to 5.57 percent for the EMG. Relative to the one-slow-mechanism formulation, allowing more than one slow mechanism produced a data-dependent improvement that exceeded one order of magnitude for one of the peaks.
Design of countercurrent separation of bufadienolides from waste toad eggs by quantum mechanism-enhanced nuclear magnetic resonance.
Zhao F, Liu X, He F … +5 more , Lei Y, Li L, Zhang X, Wang Q, Zou D
J Chromatogr A · 2026 Jun · PMID 42361692 · Publisher ↗
While artificial toad breeding generates vast quantities of bufadienolide-rich waste eggs, their exploitation is hindered by high lipid content, which typically leads to column clogging and poor solubility in conventiona...
While artificial toad breeding generates vast quantities of bufadienolide-rich waste eggs, their exploitation is hindered by high lipid content, which typically leads to column clogging and poor solubility in conventional separation frameworks. In this study, a rational design for the countercurrent chromatography (CCC) separation of bufadienolides from waste toad eggs was developed using quantum mechanism-enhanced NMR. Considering that signal overlapping and baseline drifting of complex natural mixtures often impede accurate CCC solvent system design, quantum mechanical spin analysis was employed to deconvolve individual spectral information from the mixture. This allowed for precise proton signal characterization and quantitation, which served as the foundation for calculating and designing the optimal CCC separation parameters. Implementing this designed approach led to the efficient, high-purity separation of target bufadienolides. It demonstrates that quantum mechanism-enhanced NMR is a promising strategy for the rational design of CCC separation processes to facilitate the high-value valorization of complex natural waste.
Simultaneous determination of multiple organotin compounds in fish oil by GC-MS following method development and optimization.
Liyuan W, Zhenying X, Jing C … +3 more , Zhengyan H, Pinggu W, Ying Y
J Chromatogr A · 2026 Jun · PMID 42361691 · Publisher ↗
(1) Background: Given the contamination risks of organotin compounds (OTCs) in fish oil and their potential threat to consumer health, this study addresses the analytical challenges posed by complex matrices and OTC degr...
(1) Background: Given the contamination risks of organotin compounds (OTCs) in fish oil and their potential threat to consumer health, this study addresses the analytical challenges posed by complex matrices and OTC degradation. A highly efficient and sensitive gas chromatography-mass spectrometry (GC-MS) method was established and optimized. This method enables the simultaneous qualitative and quantitative determination of multiple OTCs, providing reliable technical support for the quality and safety monitoring of dietary supplements. (2) Methods: After cryogenic extraction, sorbent cleanup, and derivatization with sodium tetraethylborate, samples were subjected to n-hexane extraction and further purification usiss identification and quantified using the internal standard method. This approach significantly improved separation efficiency and detection throughput through systematic optimization of pretreatment and instrumental conditions. (3) Results: Results showed that using 3% acetic acid-acetonitrile for the extraction of 0.5 g spiked fish oil improved efficiency by over 20% compared to single solvents. A dual-stage cleanup using 0.2 g HCC18 combined with a Florisil column provided optimal delipidation, with recoveries remaining above 80%. The nine organotins exhibited good linearity (R² ≥ 0.99) in the range of 2.0-750.0 μg/L. The limits of detection (LOD) and quantification (LOQ) were 0.151-0.439 μg/kg and 0.453-1.317 μg/kg, respectively. Spiked recoveries ranged from 81.1% to 105% with RSDs of 0.99-5.73%. (4) Conclusions: This study significantly enhanced the performance of GC-MS for detecting organotin compounds in fish oil by introducing a systematically optimized dual-stage cleanup strategy combining HCC18 and Florisil. This approach effectively eliminated lipid interference, thereby improving accuracy and sensitivity. Method validation demonstrated the method's reliability and practicality. These findings provide a high-sensitivity, anti-interference detection solution for the dietary supplement industry, holding significant public health implications for reducing consumer exposure to neurotoxic substances.
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