J Chromatogr A [JOURNAL]
Sun
200 papers
HILIC-like separation on a base-deactivated C column for ion-pair-free LC-MS/MS analysis of 16 aminoglycosides in foods.
He J, Shen L, Xu D … +5 more , Sun T, Chen Y, Hu J, Ji Y, Yan L
J Chromatogr A · 2026 Aug · PMID 42314504 · Publisher ↗
An LC-MS/MS method was developed for the simultaneous determination of 16 aminoglycosides (AGs) in pork, chicken, milk, and eggs using a conventional Hypersil base-deactivated silica (BDS) C column operated under HILIC-l...
An LC-MS/MS method was developed for the simultaneous determination of 16 aminoglycosides (AGs) in pork, chicken, milk, and eggs using a conventional Hypersil base-deactivated silica (BDS) C column operated under HILIC-like conditions. Unlike typical C-based methods that rely on ion-pairing reagents in the LC mobile phase, separation was achieved with an ion-pair-free mobile phase consisting only of 0.1% formic acid and acetonitrile under gradient elution. Column comparison, aqueous-fraction experiments, and SRM 870 probe testing indicated a mixed retention mechanism involving hydrophilic partitioning into a water-enriched interfacial layer and reversible interactions with accessible residual silanol sites. Because the method prioritizes MS compatibility and reproducible multi-residue quantification, compound-specific MRM transitions and matrix-matched calibration were used to ensure selectivity and quantitative reliability. The method showed good linearity (R² > 0.99), satisfactory accuracy (71.2-99.8%) with reported standard deviations, acceptable precision (CV ≤ 11.3%), and low detection limits (LODs 3-15 μg/kg; LOQs 10-50 μg/kg). Overall, this work demonstrates that a conventional C column can exhibit pronounced hydrophilic selectivity under high-organic conditions, offering a practical, MS-friendly alternative for aminoglycoside residue analysis and informing future stationary-phase development for hydrophilic separations.
Electrically driven elution in digital protein a membrane chromatography: An alternative to traditional low-pH elution.
Kaur S, Kick J, Frech C
J Chromatogr A · 2026 Aug · PMID 42314503 · Publisher ↗
Digital Protein A Membrane Chromatography (DMC) introduces an innovative antibody purification method that enables gentle elution using electrical fields rather than conventional low-pH buffers. By eliminating acidic con...
Digital Protein A Membrane Chromatography (DMC) introduces an innovative antibody purification method that enables gentle elution using electrical fields rather than conventional low-pH buffers. By eliminating acidic conditions, DMC mitigates antibody degradation and aggregation associated with traditional Protein A chromatography. In this study, we investigated electrically driven elution in preparative Protein A membrane chromatography with the i3 DMC device (i3 Membrane GmbH, Radeberg, Germany). The effects of applied voltage, buffer composition, and salt type and concentration were systematically evaluated to clarify the underlying elution mechanisms. Effective elution occurred only with low-conductivity buffers and solutions, requiring specific salts at appropriate concentrations, for example 0.15 mM Na₂SO₄ or 1.0 mM NaCl, which yielded high antibody recovery. Applying voltage to induce elution, showed consistent pH shifts. When the electric field was oriented from anode to cathode, the pH increased, representing the optimal condition for voltage-driven elution; reversing polarity decreased the pH. The results support the hypothesis that the elution mechanism is primarily driven by electrochemical reactions at the electrodes, leading to water electrolysis. Hydroxide ions resulting from cathodic hydrogen evolution reactions (HER) increase pH, while protons from anodic oxygen evolution reactions (OER) likely induce conformational changes in Protein A and IgG, initiating elution. These reactions are strongly influenced by the applied voltage as well as the chemical composition and ionic properties of the buffers. Collectively, these parameters exert a significant impact on elution efficiency and reproducibility. This work demonstrates that electrically driven elution provides a promising alternative to low-pH based methods, enabling milder purification of antibodies through electrochemical modulation.
Methodological challenges in machine learning and deep learning applied to food analysis: A critical review.
Felizzato G, Bagnulo E, Tapparo G … +4 more , Botta G, Cordero C, Liberto E, Caratti A
J Chromatogr A · 2026 Aug · PMID 42314502 · Publisher ↗
Artificial Intelligence (AI) is increasingly applied for food quality control, authenticity assessment, and chemical profiling. However, the reliability and industrial applicability of Machine Learning (ML) and Deep Lear...
Artificial Intelligence (AI) is increasingly applied for food quality control, authenticity assessment, and chemical profiling. However, the reliability and industrial applicability of Machine Learning (ML) and Deep Learning (DL) models critically depend on how the datasets are constructed, validated, and interpreted. Among the different analytical techniques used in food analysis, chromatographic fingerprints and chromatographic hyphenated techniques typically generate high-dimensional datasets characterised by structured peak distributions, retention time variability, and strong multicollinearity among adjacent variables, making model development and validation more challenging. These features, combined with limited sample sizes typical of food studies, pose significant challenges for model generalisation and transferability across analytical batches and industrial settings. This work provides a critical evaluation of methodological practices in ML and DL, supported by a systematic review of 165 peer-reviewed studies published between 2015 and 2025. Particular attention is given to common issues such as class imbalance, the misuse of analytical replicates, and the widespread reliance on internal cross-validation without independent test sets. To experimentally assess these factors, a chromatographic dataset on coffee origins was used as a case study to examine how unbalanced class distributions, varying training set sizes, and replicate handling affect model performance. Our results show that high-fold cross-validation and Leave-One-Out Cross-Validation consistently overestimate model accuracy compared to external validation, while treating analytical replicates as independent samples artificially inflates performance without improving true predictive power. Learning curves reveal that most ML models plateau with moderate training sizes, whereas DL models require substantially larger datasets to avoid overfitting. The findings highlight that rigorous validation strategies and careful management of chromatographic data are essential for developing robust, reproducible, and industrially transferable ML models in food chromatography.
Normalized peak distribution uniformity metrics for chromatographic evaluation.
Buff M, Guillarme D, Kormány R … +1 more , Fekete S
J Chromatogr A · 2026 Aug · PMID 42308668 · Publisher ↗
Peak distribution uniformity (DU) has been introduced as a dimensionless descriptor to characterize the global distribution of chromatographic peaks across the elution window and to complement resolution-based separation...
Peak distribution uniformity (DU) has been introduced as a dimensionless descriptor to characterize the global distribution of chromatographic peaks across the elution window and to complement resolution-based separation metrics. However, the original DU formulation may assume negative values in chromatograms exhibiting pronounced peak clustering, even when all peak pairs remain baseline-resolved, thereby limiting its interpretability and practical use in composite quality metrics. In this study, the behavior of the original DU definition is critically examined using simulated chromatograms, and two revised DU formulations are proposed. Both revised metrics are based on the statistical dispersion of inter-peak spacing and ensure that the metric remains within a suitable interval [0,1]. Their numerical behavior is evaluated using representative peak distributions and sensitivity analyses in model peak systems of varying complexity. The results demonstrate that the revised DU formulations have continuous, bounded, and physically meaningful behavior across a wide range of peak-clustering scenarios. Note that DU is one of the parameters proposed to calculate the overall quality of a separation (SQF).
3D simulation of flow field heterogeneity impact on mass transfer for emodin recovery in a packed adsorption column.
Qian W, Wang P, Huang Y … +4 more , Tang J, Shi C, Yang J, Lin X
J Chromatogr A · 2026 Aug · PMID 42302627 · Publisher ↗
This study presents a comprehensive 3D computational fluid dynamics (CFD) framework, coupled with a linear driving force (LDF) model, to investigate the impact of flow field heterogeneity on the dynamic adsorption of emo...
This study presents a comprehensive 3D computational fluid dynamics (CFD) framework, coupled with a linear driving force (LDF) model, to investigate the impact of flow field heterogeneity on the dynamic adsorption of emodin (EMO) in packed columns. The packed column has an inner diameter of 19.98 mm and a bed height of 0.05 cm, packed with DX06 adsorbent particles having an average diameter of 0.662 mm. Combined with steady Darcy-Brinkman flow and transient mass transfer equation, the model was validated through seven fixed-column experiments using lab-synthesized DX06 resin under varying operational conditions. 3D simulations revealed significant spatial velocity variations, including near-wall oscillations, interstitial high-velocity corridors, and quasi-stagnant zones, creating heterogeneous distributions of local mass transfer coefficients. Parametric analysis showed that increasing inlet EMO concentration accelerated breakthrough and exhaustion times. An optimal flow rate of 1 mL/min was identified, balancing external film resistance and residence time to maximize the overall mass transfer coefficient (K = 3.57 × 10⁻ m/s). Furthermore, the mass transfer zone (MTZ) evolution was characterized in three distinct stages: formation (0 to 41 min, HMTZ = 3.02 cm), migration (41 to 86 min), and moving-out (86 to 235 min). Molecular docking revealed that π-π stacking interactions dominate the EMO/DX06 adsorption mechanism. Reusability tests confirmed stable performance over three cycles. This 3D CFD-LDF approach provides a robust tool for the design and optimization of industrial packed-bed adsorption systems.
Rapid quantification of per- and polyfluoroalkyl substances (PFAS) in complex wastewater matrices via online SPE-LC-MS/MS method.
Guerra de Navarro M, Cuchimaque Lugo C, Quinete N
J Chromatogr A · 2026 Aug · PMID 42302626 · Publisher ↗
Expanding monitoring requirements for per- and polyfluoroalkyl substances (PFAS) in water systems require high-throughput analytical methods capable of processing large numbers of environmental samples. These needs have...
Expanding monitoring requirements for per- and polyfluoroalkyl substances (PFAS) in water systems require high-throughput analytical methods capable of processing large numbers of environmental samples. These needs have intensified following the Final National Primary Drinking Water Regulation established by the United States Environmental Protection Agency. Conventional PFAS extraction and workflow typically require multistep procedures exceeding six hours and large sample volumes (up to 500 mL), limiting laboratory throughput. This study presents a rapid online solid-phase extraction liquid chromatography mass spectrometry (SPE-LC-MS/MS) method for the quantification of 37 PFAS aligned with EPA Method 1633. The method requires minimal sample preparation consisting of centrifugation, filtration and five-fold dilution, resulting in a final analyzed volume of 2 mL. Online SPE using a weak anion exchange (WAX) sorbent coupled with LC-MS/MS analysis on a pentafluorophenyl (PFP) column enabled a total analysis time of 30 min per sample. Validation demonstrated linearity, precision, and accuracy, with method detection limits as low as 1.74 ng/L for PFOA and 3.65 ng/L for PFOS. Application to municipal wastewater samples from Miami-Dade, FL, including influents, effluents, and septage, indicated short-chain PFAS prevalence. PFBA (77-1908 ng/L) was detected in all samples. Seasonal trends showed significantly higher concentrations in the efluent during the wet season (∑PFAS = 467 ng/L dry and 1251 ng/L wet). Removal efficiency varied by season: during the dry season, only PFPeA and PFHpA showed measurable removal, whereas compounds such as 5:3 FTCA, N-MeFOSE, and PFDS were completely removed in the wet season, likely due to precursor transformation under aerated conditions.
Editorial VSI: Nucleic acids based drugs.
Studzińska S, Rentel C
J Chromatogr A · 2026 Aug · PMID 42297671 · Publisher ↗
Abstract loading — click title to view on PubMed.
A study of pragmatic hazard-informed triage workflow intervention for occupational hygiene risk governance: Routine GC-FID chromatographic fingerprints as exposure-intelligence early-warning signals.
Zhang Z, Guo K, Shen Y … +3 more , Ma K, Zhang J, Sun H
J Chromatogr A · 2026 Aug · PMID 42296846 · Publisher ↗
BACKGROUND: Occupational hygiene practices often treat compliance with occupational exposure limits (OEL) as an operational endpoint. However, OEL-compliant processes can still harbor preventable risks when hazard lists...
BACKGROUND: Occupational hygiene practices often treat compliance with occupational exposure limits (OEL) as an operational endpoint. However, OEL-compliant processes can still harbor preventable risks when hazard lists are incomplete or processes are upset. METHODS: We evaluated a novel, pragmatic governance intervention workflow that repurposes routine gas chromatography-flame ionization detection (GC-FID) chromatograms as 'exposure-intelligence' early-warning signals that can trigger prioritized confirmation and preventive action. Decisions are thus reordered from 'assume hazards then quantify targets' toward 'detect anomalous fingerprints, triage by hazard priority, confirm selectively, act, and remonitor.' With explicit handling of unknowns via a precautionary principle that assigns highest hazard potential and maximum uncertainty by default. The workflow comprises Tier-1 screening, Tier-2 hazard-informed triage and confirmation screening, and Tier-3 confirmation and action. Accordingly, we applied standardized GC-FID analysis to thermal desorption and solvent desorption samples from across automotive, electronics, and pharmaceutical manufacturing, which we converted into retention-time-aligned fingerprints. Anomalies were flagged against site-by-task baselines (robust statistics) and prioritized by signal magnitude, recurrence, candidate hazard band, and quality control (QC) uncertainty, triggering targeted gas chromatography-mass spectrometry (GC-MS) confirmation and action logging. RESULTS: From 45,765 chromatograms (237 sites and 37 tasks), screening flagged anomalies in 16.4% (2.3% false alarms, primarily QC/background artifacts). Targeted confirmation averaged 57 GCMS- analyses per month. Implementation was associated with shorter time-to-action (median 28 to 11 days; Cox hazard ratio, 2.4), higher confirmation positive predictive value for actionable high-concern leads (47%vs 23%), and reduced unexplained peak burden after controls (median -22% peaks/windows; -17% unexplained area fraction). CONCLUSION: Routine GC-FID fingerprints can therefore operationalize scalable early warnings and risk-prioritized confirmation, complementing OEL-based compliance with faster, auditable preventive governance.
Rapid spatial distribution analysis of lipids in wheat grain using DESI/PI mass spectrometry imaging.
Pan Y, Wang Y, Wen Z … +5 more , Wang W, Li N, Sun Q, Liu C, Pan Y
J Chromatogr A · 2026 Aug · PMID 42287838 · Publisher ↗
Wheat is an important cereal grain. Understanding lipid composition and distribution in wheat grain is valuable for plant, food and nutritional research. Conventional methods can analyze lipid composition and content in...
Wheat is an important cereal grain. Understanding lipid composition and distribution in wheat grain is valuable for plant, food and nutritional research. Conventional methods can analyze lipid composition and content in wheat grain, while the spatial native distribution of lipids is inevitably lost. In this paper, an effective mass spectrometry imaging (MSI) analysis protocol combining desorption electrospray ionization/post-photoionization (DESI/PI) with high-resolution mass spectrometer was established. To overcome the hardness of wheat grains and fragility of wheat grain sections, a rapid hand plane sectioning (HPS) method was developed. By employing accurate mass spectrometry peak identification, the HPS samples detection results achieved ∼23 % similarity with cryosectioning sample (same compounds). DESI/PI has good sensitivity for both non-polar and polar lipids. A small mass spectrum database for wheat grain was established which may provide strong data support for wheat grain component analysis. The rapid MSI analysis protocol was further used to explore the spatial distribution changes of lipids in wheat grain with different storage years, indicating that DESI/PI was a potential means of studying wheat grain aging. This study provides a convenient sectioning method, a comprehensive identification checklist, and spatial distribution information of lipids in wheat grains, which holds potential significance for guiding improvements in wheat grain processing & storage, slowing down the aging, and ensuring grain quality.
N, N-diethylhydroxylamine, morpholine, and cyclohexylamine analysis in steam turbine water by gas chromatography with chemiluminescence detection.
Luong J, Hawryluk M, Gras R
J Chromatogr A · 2026 Aug · PMID 42287837 · Publisher ↗
We have developed a fast, reliable, and cost-effective analytical method for determining N,N-diethylhydroxylamine, morpholine, and cyclohexylamine in aqueous matrices. These compounds are essential oxygen scavengers used...
We have developed a fast, reliable, and cost-effective analytical method for determining N,N-diethylhydroxylamine, morpholine, and cyclohexylamine in aqueous matrices. These compounds are essential oxygen scavengers used in several industrial applications including boiler water treatment to prevent corrosion in steam turbines. By leveraging gas chromatography coupled with nitrogen chemiluminescence detection, our technique offers exceptional sensitivity, selectivity, and ease of use. A 30 m × 0.32 mm i.d. × 3 µm column, composed of 5% phenyl and 95% dimethylpolysiloxane, specifically optimized for nitrogen-containing compounds, was used for separating the analytes. A co-solvent approach with 1:1 ratio of 2-propanol and water was used to enhance chromatographic peak symmetry in highly polar matrix likes water. Nitrogen chemiluminescence detection advantageously yields a compound-independent response for nitrogen, enabling the quantification of analytes with any organic nitrogen chemicals detectable by gas chromatography, with an accuracy of ±5%. This method streamlines the workflow and reduces operational costs. Method performance metrics include a detection limit of 0.1 ppm (w/w) N, a relative standard deviation (RSD) of <3% at 100 ppm (w/w), and an analysis time of under 11 min while maintaining a high degree of selectivity. Validated with real-world samples from steam turbine condensate and commercial car wash water, this method demonstrates robust performance and reproducibility. The rapid turnaround, minimal maintenance, and low cost of ownership make this technique an optimal solution for routine monitoring in industrial settings. This research work represents a significant advancement in boiler water analysis, combining analytical rigour with practical efficiency to support asset integrity and operational reliability.
Green and integrated recovery of luteolin from peanut shells using ionic liquid-microwave extraction and macroporous resin purification.
Si X, Zhang S, Li L … +1 more , Sheng Z
J Chromatogr A · 2026 Aug · PMID 42287836 · Publisher ↗
Peanut shells, an abundant agricultural by-product, represent a promising source of the bioactive flavonoid luteolin. This study developed a green and efficient strategy for luteolin recovery by integrating ionic liquid-...
Peanut shells, an abundant agricultural by-product, represent a promising source of the bioactive flavonoid luteolin. This study developed a green and efficient strategy for luteolin recovery by integrating ionic liquid-based microwave-assisted extraction (IL-MAE) with macroporous resin purification. The IL-MAE process was optimized using response surface methodology (RSM), achieving a maximum yield of 3.36 mg/g under optimal conditions: [BMIM][BF₄] concentration of 2 mol/L, liquid-to-solid ratio of 27 mL/g, microwave power of 800 W, and irradiation time of 120 s. Molecular dynamics simulations revealed that hydrogen bonding between luteolin and the ionic liquid governs the extraction mechanism. The crude extract was further purified using NKA-9 macroporous resin, which exhibited high adsorption capacity (2.10 mg/g) and desorption efficiency (93.57%). Dynamic adsorption studies established optimal conditions: sample pH 3.0, loading volume of 1.95 bed volumes (BV), flow rate of 2 BV/h, and temperature of 25 °C. Efficient desorption was achieved by sequential elution with water, 50% ethanol, and 70% ethanol (5 BV each), yielding a final luteolin purity of 84.1%. Notably, the ionic liquid was successfully recycled with over 90% of its initial extraction efficiency retained after multiple cycles. This integrated approach offers a sustainable and scalable pathway for valorizing agricultural waste into high-value bioactive compounds within a circular bioeconomy framework.
Resolving measurement artifacts of field-flow fractionation coupled to conventional dynamic light scattering detection by using phase and spatially-resolved dynamic light scattering to improve size accuracy.
Marioli M, Wang Y, Besseling R … +2 more , Verhoeven MCM, Schuurmans CCL
J Chromatogr A · 2026 Aug · PMID 42284668 · Publisher ↗
The use of dynamic light scattering (DLS) as an online detector in asymmetrical flow field-flow fractionation (AF4 ‒ DLS) for size characterization is known to introduce measurement bias for particles with hydrodynamic s...
The use of dynamic light scattering (DLS) as an online detector in asymmetrical flow field-flow fractionation (AF4 ‒ DLS) for size characterization is known to introduce measurement bias for particles with hydrodynamic size exceeding ∼100 nm. This study demonstrates that the accuracy of hydrodynamic size measurements in AF4 ‒ DLS is significantly improved by applying advanced phase and spatially-resolved DLS (PhaSR-DLS) detection. PhaSR-DLS overcomes two limitations of conventional DLS: (i) overestimation of particle size due to 'number fluctuations' at low particle concentrations, causing 'U-turn' shaped size profiles and (ii) underestimation of particle size due to the flow through the detector flow cell. These improvements are demonstrated by analyzing mixtures of 100 nm and 200 nm polystyrene particles at different concentrations and detector flow rates using AF4 coupled online to both PhaSR-DLS (AF4 ‒ PhaSR-DLS) and conventional DLS (AF4 ‒ DLS) simultaneously for comparison. Accuracy improvements with AF4 ‒ PhaSR-DLS are most significant at the highest flow rate (0.80 mL/min), where the large biases are removed or significantly reduced (from -19% to 0% error for the 100 nm standard and from -36% to -5% error for the 200 nm standard). Furthermore, using direct concentration measurements from AF4 ‒ PhaSR-DLS, it is shown that accurate particle size can be achieved at concentrations as low as 10 particles/mL. Since the measurement accuracy depends on the particle size, particle concentration, and detector flow rate, these findings show that use of PhaSR-DLS in AF4 can significantly improve accuracy and robustness for a range of applications using nanoparticles of different compositions and morphologies.
A deep eutectic solvent-assisted green synthesis of advanced three-dimensional covalent organic framework based stationary phase for dual-mode liquid chromatography.
Fang N, Long H, Du H … +4 more , Liu Y, Zhang Y, Chen W, Tang S
J Chromatogr A · 2026 Aug · PMID 42284667 · Publisher ↗
Two-dimensional covalent organic frameworks (2D COFs) are widely used as stationary phases in liquid chromatography, yet their simple pore structures often mandate surface modifications to attain the necessary separation...
Two-dimensional covalent organic frameworks (2D COFs) are widely used as stationary phases in liquid chromatography, yet their simple pore structures often mandate surface modifications to attain the necessary separation selectivity. In contrast, three-dimensional COFs (3D COFs) feature customizable hierarchical channel systems with complex pore structures, high specific surface areas, and spatially diversified active sites, enabling superior separation selectivity and enhanced column efficiency. Furthermore, their rigid frameworks prevent structural collapse of stationary phase, offering unique advantages for advanced separations. Therefore, the development of innovative 3D COF@silica stationary phase represents a promising strategy that leverages the established benefits of silica supports while incorporating the tunable porosity and functionality of 3D COFs. This work presents an eco-friendly deep eutectic solvent-mediated synthesis of an imine-linked 3D-Azo-TFPM-COF@silica stationary phase, which eliminates hazardous solvents and reduces reaction time. The synthesized material demonstrated excellent chromatographic performance in separating polar compounds and positional isomers. Meanwhile, the 3D-Azo-TFPM-COF@silica column was applied to cosmetic analysis for quantifying nicotinamide content in commercial whitening essences with high accuracy (recovery: 95.82-102.92%) and good precision (RSD < 0.4%). This work presents a straightforward and green synthetic approach for 3D COF based stationary phases, broadening their application in chromatographic separations and demonstrating their potential for advanced analytical techniques.
Corrigendum to "In-line spectroscopic measurement of pH profiles using methyl orange: Application to pH transients in protein A chromatography" [Journal of Chromatography A 1782 (2026) 467106].
Moser AR, Zha RH, Cramer SM
J Chromatogr A · 2026 Aug · PMID 42276942 · Publisher ↗
Abstract loading — click title to view on PubMed.
Online monitoring of catechin compounds transformation by the stationary phase of star phenylalanine cyclodextrin polymer.
Bai H, Zhao Y, Zhang S … +1 more , Chen L
J Chromatogr A · 2026 Aug · PMID 42275811 · Publisher ↗
The active ingredients of natural products represent a critical source for innovative drug discovery. However, the poor stereochemical stability and transformation of stereoisomers during storage directly influence thera...
The active ingredients of natural products represent a critical source for innovative drug discovery. However, the poor stereochemical stability and transformation of stereoisomers during storage directly influence therapeutic efficacy and safety. Therefore, the development of new chiral stationary phases (CSPs) with high chiral and structural selectivity is imperative for reliable quality control of natural products. Here, a star phenylalanine cyclodextrin (CD) polymer, Star-Phe-CD, was designed and synthesized. It features a CD parent nucleus, with Phe-derivatized CD as the sidechain monomers. Subsequently, a mixed-mode Sil-Star-Phe-CD CSP was fabricated with Star-Phe-CD as the chiral ligand, which exhibited significant fluorescence enhancement effects and multiple mixed-mode chromatographic retention mechanisms. The Sil-Star-Phe-CD CSP exhibits exceptional shape selectivity and stereoselectivity towards structurally similar analytes, demonstrating outstanding stereoseparation selectivity for analytes with rigid structures or multiple benzene rings with α = 1.90 and α = 1.55, respectively. Coupled with LC-MS analysis, an online approach was established to simultaneously separate two pairs of catechin epimers and monitor their epimerization process. Molecular docking studies revealed the mechanism of chiral recognition, which relies on the cooperative effects of diverse intermolecular interactions, including hydrogen bonding, π-π interactions, and hydrophobic interactions. These interactions are crucial for recognizing structurally similar stereoisomers in complex systems.
Separation of radium and actinium in acetic acid/acetate solutions using TK101 resin.
Kmak KN, Despotopulos JD, Coupannec M … +1 more , Huynh TL
J Chromatogr A · 2026 Aug · PMID 42269549 · Publisher ↗
The uptake and elution behavior of Ra and Ac was studied on TK101 resin using acetic acid and acetate buffer (acetic acid/lithium acetate) solutions. There is high extraction of Ra (>10) over a wide range of acetic acid...
The uptake and elution behavior of Ra and Ac was studied on TK101 resin using acetic acid and acetate buffer (acetic acid/lithium acetate) solutions. There is high extraction of Ra (>10) over a wide range of acetic acid concentrations (0.02 to 4 M) with slightly lower extraction (>10) in the acetate buffer solutions (pH 3.9 to 5.6). The Ac extraction is considerably lower with a maximum D of ∼100, and negligible extraction at high acetic acid concentrations (> 1 M) and in the acetate buffer solutions. The difference in D can be leveraged for highly efficient separations of Ac from Ra, with no detectable Ra in the Ac fractions and high Ac yields (∼100%). These separations may be useful for radiopharmaceutical applications as the Ac purity is extremely high and the elution conditions can be optimized to be biologically safe and appropriate for chelation to molecules relevant to targeted alpha therapy.
Pyridines in food samples: Recent updates on pretreatment and analytical methods.
Yang HY, Zhang Y, Wen ZF … +2 more , Zhu J, Feng XS
J Chromatogr A · 2026 Aug · PMID 42269548 · Publisher ↗
Pyridines, a kind of vital heterocyclic organic compounds, find extensive applications across various industries, including their use as flavoring agents in food products, as well as in the formulation of pesticides and...
Pyridines, a kind of vital heterocyclic organic compounds, find extensive applications across various industries, including their use as flavoring agents in food products, as well as in the formulation of pesticides and herbicides. Notably, pyridines are a key component of a wide range of food volatile compounds. However, due to their prevalent usage patterns, pyridine residues frequently persist on food products. The accumulation of pyridine beyond safe thresholds may potentially jeopardize human health through multiple exposure pathways, including inhalation, ingestion, and dermal absorption. Furthermore, variations in pyridine concentration can significantly alter the volatile odor profile of food items. Consequently, there is a pressing demand for analytical methods capable of accurate, rapid, and sensitive detection of pyridine, along with efficient sample pretreatment protocols to handle diverse food samples. This review critically assesses recent advancements. While novel solid-phase extraction materials, such as molecularly imprinted polymers and magnetic nanomaterials, enhance selectivity and recovery, their cost and synthesis complexity warrant consideration. For detection, mass spectrometry (MS) platforms -notably gas chromatography-MS and high-performance liquid chromatography-MS- remain the gold standard for trace analysis due to their sensitivity and specificity, though they are laboratory-bound. Emerging sensor technologies present a promising, though often less sensitive, pathway for rapid on-site screening, potentially bridging the gap between the lab and the field.
Detailed analysis of ACETEM emulsifiers and emulsifier products.
Schuster K, Wernlein T, Wang T … +3 more , Kunz C, Hölzle E, Oellig C
J Chromatogr A · 2026 Aug · PMID 42269547 · Publisher ↗
Only a few methods are currently available for the qualitative and quantitative analysis of ACETEM emulsifiers, which are defined as acetic acid esters of mono- and diacylglycerols of edible fats and oils. These emulsifi...
Only a few methods are currently available for the qualitative and quantitative analysis of ACETEM emulsifiers, which are defined as acetic acid esters of mono- and diacylglycerols of edible fats and oils. These emulsifiers are structurally closely related to fats, making their analysis particularly challenging in fat-containing matrices. In the present study, an ACETEM emulsifier and an ACETEM-containing product selected by stratified random sampling are characterized using different analytical techniques such as high-performance thin-layer chromatography-fluorescence detection (HPTLC-FLD) and coupling to mass spectrometry (TLC-MS), high-performance liquid chromatography coupled to MS (HPLC-MS), direct infusion electrospray ionization tandem MS (DI-ESI-MS/MS), and nuclear magnetic resonance spectroscopy (NMR). Furthermore, a method for the semi-quantitative determination of selected ACETEM compounds by HPLC-MS/MS was developed, which involved the synthesis of four analytical standards (mono- and diacetylated glycerol 1-monopalmitate and glycerol 1-monostearate). The determination of these substances in six ACETEM emulsifiers showed that these compounds make up 16-97% of the analyzed emulsifiers, with considerable variation in the proportion of mono- and diacetylated species.
Supercritical fluid chromatography for Diastereoselective resolution of Cyclopentane Diol core: a scalable approach to chiral purity.
Murugesan S, Madam R, Dodda CAR … +7 more , Vinod T, Suda L, Beeregowda R, Bhattasali D, Mathur A, Gupta A, Jarugu LB
J Chromatogr A · 2026 Aug · PMID 42269546 · Publisher ↗
Preparative supercritical fluid chromatography (SFC) method was successfully developed and implemented for the large-scale resolution of four closely related diastereomers of a cis-cyclopentane diol intermediate, a key s...
Preparative supercritical fluid chromatography (SFC) method was successfully developed and implemented for the large-scale resolution of four closely related diastereomers of a cis-cyclopentane diol intermediate, a key structural fragment in a lead discovery candidate. The separation leveraged the unique physicochemical properties of supercritical CO₂, whose low viscosity and high diffusivity enable high linear velocities while maintaining column efficiency, thereby facilitating rapid and scalable separations. Diastereomeric resolution was achieved on a polysaccharide-based chiral stationary phase, where differential hydrogen bonding, steric fit, and dipole-dipole interactions between the multiple hydroxyl functionalities of the analytes and the chiral selector governed selectivity. Fine control of the mobile-phase composition-specifically the percentage and nature of the polar organic modifier (e.g., methanol or ethanol), along with basic or acidic additives-proved critical for modulating analyte solubility, peak shape, and resolution. From a scalability perspective, challenges such as sample solubility limits, pressure drop management, and consistent retention behaviour during column scale-up were systematically addressed through solvent strength optimization and loading studies. The resulting preparative SFC process delivered high throughput, excellent recovery, and reproducible stereochemical purity, underscoring the suitability of SFC as a robust and efficient platform for multigram to kilogram-scale diastereomer separations in early pharmaceutical development.
A comparison of mathematical models in the plate and rate theory of chromatography.
Hao W, Li B, Jiang L … +4 more , Qi X, Deng Y, Tang J, Cai L
J Chromatogr A · 2026 Aug · PMID 42258991 · Publisher ↗
The mathematical models in the plate theory of chromatography are solved by using a statistical approach. An equation for the number of theoretical plates is proposed which can unify the equations that are deduced from t...
The mathematical models in the plate theory of chromatography are solved by using a statistical approach. An equation for the number of theoretical plates is proposed which can unify the equations that are deduced from the continuous flow (CF) and discontinuous flow (disCF) model respectively. The models are compared with those in the rate theory of chromatography such as the equilibrium dispersive (ED), transport (TR), Wade-Lucy-Carr (WLC), transport dispersive (TD) and general rate (GR) model. In the case of high column efficiency, expressions are given to account for the relationship between the parameters in the CF and ED model and those in the disCF and TR model. A ratio parameter is proposed to account for the contribution to peak variance of the finite rate of the equilibrium or the mass transfer kinetics between mobile and stationary phase. It is used to calculate the plate height and can be measured in experiments by changing mobile phase composition slightly. It is also demonstrated that the TR and WLC model will be equivalent when the adsorption isotherm is linear. When the adsorption isotherm is nonlinear, a nonlinear driving force equation is deduced from the Langmuir kinetics equation, which can explain the concentration dependence of the rate coefficient in the TR model which has been reported in literature.
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