Journal of Chromatography A最新文献

In this work, a novel sulfonic acid-functionalized microporous organic network-coated SiO₂ composite (SiO₂@MON-SO₃H-2) was synthesized for efficient solid-phase extraction (SPE) of quaternary ammonium alkaloids (QAAs) from complex traditional Chinese medicine (TCM) samples. The material exhibits a high specific surface area (381.4 m² g^-1), superhydrophilicity, and excellent stability. These properties, combined with synergistic interactions such as electrostatic attraction, hydrophobic effects, and π-π stacking, enabled the adsorbent to demonstrate outstanding extraction performance toward four typical QAAs. The developed method owns wide linear ranges (0.88-1000 μg L^-1) with good linearity (R² > 0.999), high sensitivity (limits of detection: 0.26-1.02 μg L^-1), satisfactory precision (intra- and inter-day RSDs < 6.3%), high enhancement factors (> 91), and insignificant matrix effects (86.6-115.3%). The material maintained excellent reusability, with recoveries remaining above 89% after 50 extraction-desorption cycles. When applied to spiked herbal matrices, the method provided recoveries of 92.7-112.0%. SiO₂@MON-SO₃H-2 also gave higher recovery than commercial C18, activated carbon, macroporous adsorption resin AB-8, and the cation-exchange resin Amberlite 732. The present work demonstrates the prospect of SiO₂@MON-SO₃H-2 for trace QAAs extraction from complex samples and provides a reliable approach for TCM analysis and quality control.

Lipids produced by different organisms are preserved as fossils in sediments and soils. These so-called lipid biomarkers and related organic proxies represent valuable tools to reconstruct past changes in ecosystems. For example, C₃₇ alkenones produced by microalgae (Isochrysidales) represent biomarkers specific for these organisms. Furthermore, an index based on C₃₇ alkenones can be used as proxy to estimate past changes in surface water temperature. However, before analysis by gas or liquid chromatography and mass spectrometry, biomarkers extracted from the sediment are treated by solid phase extraction (SPE), a process which is time-consuming and requires the use of organic solvents which can be harmful to health and environment. Here, we compared a routinely applied manual SPE (mSPE) analytical method with an automated SPE (aSPE) method using a PrepLinc platform automated sample preparation system (J2 Scientific). The analysis of marine sediments from the North Sea and the Southeast Pacific conducted with both mSPE and aSPE resulted in mainly statistically similar results, although care has to be taken when compound co-elution occurs. aSPE resulted in a higher recovery rate, but consumed more solvents, mainly for rinsing. The use of the PrepLinc platform for automated SPE, which can process up to 27 samples in a single run, allows saving not only time, but also fume hood space as the PrepLinc platform has a completely closed circuit. The PrepLinc platform represents, thus, a valuable instrument to perform automated SPE for the analysis of environmental lipid biomarkers with a high repeatability.

Developing sustainable and efficient separation technologies is crucial for achieving a green transformation in the bioprocessing industry. This study proposes an innovative chromatographic material that utilizes abundant pine wood as raw material. It employs a dextran grafting strategy to functionalize the substrate, resulting in the preparation of high-capacity anion-exchange monolithic columns. This method serves as a robust sustainability strategy, converting low-value biomass into high-value separation media. The optimized monolithic material exhibits a static adsorption capacity of 122.1 mg g^-1 for bovine serum albumin and a dynamic capacity of over 97 mg g^-1. Leveraging the natural convective channels within wood, the material achieves rapid binding kinetics and exhibits excellent column permeability of 1.12 × 10^-10 m². Its exceptional reusability (over 100 cycles) and long-term stability further demonstrate its practicality and economic viability. We validated its practical application value by successfully purifying target proteins from complex mixtures. This work integrates fundamental material innovation with scalable bioprocessing technology to provide a sustainable, high-performance, and cost-effective platform for purifying proteins and other high-value bioproducts.

As a class of the most prevalent broad-spectrum antibiotics, quinolones (QNs) are ubiquitous in various environmental matrices (in particular marine sediment). However, determination of multiple QNs in marine sediment is a challengeable task due to matrix complexity and strong QNs-sediment adsorption. Herein we presented an efficient quantification strategy for accurate measurement of 15 QNs in marine sediment based on ultrasonic extraction with 0.2 M Na₂HPO₄ in 50 v/v % acetonitrile, followed by automated solid-phase clean-up and ultra-performance liquid chromatography-tandem mass spectrometry with isotope dilution calibration. The method demonstrated negligible matrix effect, satisfactory recoveries (85 %-119 %), and low limits of detection (2-15 pg/g). Five QNs were detected in marine sediment from Yueqing Bay and Daiquyang with total concentrations of 5.6-12.1 μg/kg and 0.2-1.0 μg/kg, respectively, where four QNs including norfloxacin (NOR), enrofloxacin, ciprofloxacin, and ofloxacin were found in all samples, and NOR was the predominant compound both in Yueqing Bay and Daiquyang. Overall, the presented method is highly sensitive and reliable for routine quinolone analysis in marine sediment.

A rapid, convenient, and efficient dispersive solid-phase extraction approach, integrating ultraperformance liquid chromatography-tandem mass spectrometry and pretreated pine pollen, was developed for sensitive quantification of 13 heterocyclic amines (HCAs) in sesame oil. Critical parameters, namely sorbent type and dosage, adsorption mode and duration, detergent dosage, eluent additive and volume, and elution cycles, were systematically optimized to evaluate their effects on the HCA recovery. The proposed method was verified for all the 13 HCAs, demonstrating favorable analytical characteristics with remarkable linear relationships (coefficient of determination, R² ≥ 0.998), adequate recoveries (64.2%-99.4%), acceptable intra- and inter-day precision (relative standard deviations ≤ 10.4%), and low limits of detection (0.02-0.83 μg/kg) and quantification (0.07-2.70 μg/kg). The proposed approach offers distinct advantages, including rapidity, simplicity, cost-effectiveness, and minimized organic solvent consumption, demonstrating great potential for accurately analyzing HCAs in complex food matrices.

New equation expressing the optimal efficiency and optimal dimensionless solvent velocity of LC column of an arbitrary structure are derived. The use of the equations for evaluating and comparing performance of several differently structured columns has been illustrated.

Chiral separation is critical in pharmaceutical analysis, as enantiomers often exhibit distinct pharmacological activities, metabolic behaviors, and toxicity profiles. Cyclodextrins have been widely employed in capillary electrophoresis (CE) owing to their well-defined cavities and strong inclusion capabilities that facilitate effective chiral recognition. However, their relatively high cost, moderate aqueous solubility, and limited compatibility with certain analytes remain important drawbacks. In contrast, maltodextrins are inexpensive and highly soluble but display restricted chiral selectivity. To overcome these limitations, this study introduces phosphated maltodextrin (PMD), a novel anionic derivative designed to enhance enantiomeric resolution through the combined influence of electrostatic and hydrophobic interactions. PMD was synthesized via a simple aqueous method and characterized by standard spectroscopic and elemental analyses. Its chiral recognition capability in CE was systematically assessed using five model drugs: tramadol, citalopram, hydroxyzine, amlodipine, and fluoxetine. Compared with native maltodextrin, PMD markedly improved enantiomeric resolution-for example, Rs increased from 0.44 to 1.33 (tramadol), 3.37 to 7.54 (citalopram), 0.58 to 1.73 (amlodipine), and 1.88 to 4.23 (hydroxyzine). These enhancements were achieved with only minor changes in migration time (-0.75 to +2.7 min across analytes). The optimized CE conditions employed a 50 mM phosphate buffer at pH 3 containing 5% (m/v) PMD, under 20 kV and 25 °C. Method validation for citalopram and hydroxyzine confirmed excellent linearity (r² > 0.983), precision (RSD < 10.2%), and accuracy (recoveries 93.09-108.56%). The method reached quantification limits as low as 10 mg/L and was successfully applied to the enantiomeric assay of commercial tablets, yielding recoveries of 97.57-102.46% of the label claim. PMD is a new anionic chiral selector combining affordability, solubility, and enhanced selectivity. Major resolution gains without longer analysis times demonstrate PMD's promising potential for routine pharmaceutical applications, with broader chiral separations to be explored in future studies.