Journal of separation science最新文献

This work designs a titanium dioxide@covalent organic framework composite material (TiO₂-COF), which optimizes the distribution of lead adsorption sites by adjusting the position of hydroxyl groups in the COF, thereby enhancing the separation efficiency of trace Pb²⁺ ions. The composite material integrates the advantages of metal oxides and porous materials, optimizing the separation performance of Pb²⁺ ions through a synergistic enhancement effect. Additionally, its multi-interface structural characteristics provide the material with multidimensional selectivity, resulting in a highly selective separation material. In selectivity experiments, the material demonstrated high adsorption selectivity for Pb²⁺ ions compared to several other metal ions. Thermodynamic and kinetic simulation results prove that the adsorption of Pb²⁺ ions by TiO₂-COF conforms to the pseudo-second-order kinetics and the Langmuir adsorption model. After multiple cycles of use, the material still maintains high adsorption efficiency, demonstrating its potential clean and green application value in the highly selective separation of metal pollutants. The constructed material was used for the separation and preconcentration of Pb²⁺ ions, establishing a detection system for trace Pb²⁺ ions. The detection limit of the method is 0.073 µg L⁻¹ (3σ/K, n = 9), with precision ranging from 0.55% to 11.7% (n = 11), and a linear range of 0.2–5 µg L⁻¹, exhibiting strong anti-interference capability. The constructed method achieves the determination of lead ions in real samples, with recoveries ranging from 95% to 103%. Moreover, the standard material GBW08607 was analyzed through the constructed system, and the t-test shows that the calculated t-value is 2.01, which is less than the tabulated t-value of 2.57 (n = 6), proving the reliability of the method. It provides a potential alternative material for the separation and analysis of other environmental pollutants.

The Complementary Developing Solvent technique, originally developed for high-performance thin-layer chromatography, employs solvent systems with distinct polarity ranges to achieve enhanced chromatographic resolution while covering a broad chemical space. This study demonstrates the successful adaptation of low polarity developing solvent and high polarity developing solvent systems to normal-phase flash chromatography for systematic fractionation. The system suitability test used in high-performance thin layer chromatography, namely the Universal HPTLC Mix, enabled direct comparisons between high-performance thin layer chromatography and flash chromatography, demonstrating a conserved polarity-driven retention hierarchy across chromatographic scales. To confirm compound identities and elution order, each chromatographic peak was collected and analyzed by tandem mass spectrometry, with MS/MS spectra manually matched against reference standards. Quantitative chromatographic performance was benchmarked using effective peak capacity (Pc), yielding a value of 16.41 for the high-polarity developing system, indicative of a globally balanced separation. In addition, a systematic isocratic step fractionation strategy was implemented by segmenting each elution gradient (low polarity developing solvent and high polarity developing solvent) into seven predefined polarity windows. This strategy was applied on a crude methanolic extract of Sideritis scardica Griseb., confirming robust and reproducible fractionation boundaries in a complex botanical matrix. Collecting a single fraction per isocratic step significantly reduces the number of samples for subsequent analysis such as bioassays and untargeted metabolomic profiling, thereby accelerating natural product discovery and dereplication workflows.

In this study, we addressed the longstanding challenge of elucidating the complex material basis of traditional Chinese medicine (TCM) formulas by establishing an integrated, multi-platform UHPLC-QTOF MS^E data-analysis workflow for Tongqiao Huoxue Decoction (THD), a prescription widely used in the clinical treatment of cerebral infarction. Unlike conventional single-software pipelines that often suffer from incomplete spectral libraries, limited algorithmic coverage, and platform-dependent biases, our strategy combined UNIFI, MS-DIAL, QI, and FBMN to jointly process the data, thereby reducing the analytical blind spots and interference inherent to any single tool. This multi-angle identification system enabled a high-confidence characterization of 235 chemical constituents in THD and 101 in vivo metabolites detected in serum and urine samples of rats, while also revealing predominant metabolite classes potentially associated with THD's pharmacodynamic mechanisms in cerebral infarction. The resulting workflow demonstrated high accuracy, reproducibility, and efficiency, offering a rigorous and comprehensive solution for biological and medicinal sample analysis. Overall, this work not only deepens the understanding of THD's therapeutic material foundation, but also provides a novel, generalizable methodological paradigm that advances mass-spectrometry-based characterization of multi-component TCM prescriptions and their in vivo transformation profiles.

In this contribution, an efficient high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of four impurities in trihexylphe idyl hydrochloride. The developed HPLC method was based on an octadecylsilane-bonded silica gel column (Agilent TC-C18 250 mm × 4.6 mm, 5 µm) as the stationary phase, and the solvents were sodium hexafluorophosphate 0.05 mol/L and methanol for the gradient elution at a flow rate of 1.0 mL/min, with the injection volume of 20 µL, the ultraviolet (UV) detection at a wavelength of 210 nm, and the column temperature of 30°C. Under the established chromatographic conditions, all four target impurities were completely eluted within 30 min. The proposed method demonstrates good specificity, precision, robustness, and accuracy for the quantification of the four critical impurities in trihexyphenidyl hydrochloride, and was successfully applied for the analysis of trihexyphenidyl hydrochloride in a pharmaceutical preparation.

Shaoyao Ruangan Decoction (SYRGD), a classic traditional Chinese medicine (TCM) preparation composed of over a dozen herbs, is widely used in the clinical treatment of liver cancer, hepatitis, and liver cirrhosis. In this study, we elucidated the chemical basis of SYRGD and, for the first time, its in vivo metabolic pathways and dynamic gastrointestinal changes by combining ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-Q-Orbitrap-MS/MS) with the Simulator of the Human Intestinal Microbial Ecosystem (SHIME) model. Results revealed the identification of 101 constituents in SYRGD, primarily including flavonoids, terpenoids, organic acids, and alkaloids. Within the SHIME digestive fluids, 69 prototype components and 67 metabolites were identified, with the metabolic pathways primarily involving hydroxylation, oxidation, sulfation, and glucuronidation. Dynamic analysis showed that most prototype components were gradually absorbed or transformed, exhibiting a decreasing concentration gradient from the stomach to the colon. In contrast, many metabolites showed significant enrichment in the stomach and small intestine prior to their absorption or further transformation, indicating that metabolic reactions occurred throughout the entire digestive process. This study provides a comprehensive reference for the clinical application and further development of SYRGD. The systematic methodology is rapid, reproducible, overcomes the limitations of conventional animal or clinical trials, and establishes a precise research strategy for investigating the metabolism of other complex herbal medicines.

A molecularly imprinted polymer (MIP) was successfully synthesized through precipitation polymerization for the purpose of selectively extracting ketoconazole (KCZ) from cosmetic shampoo matrices. The polymerization process employed methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, azobisisobutyronitrile as the initiator, and KCZ as the template within an acetonitrile/acetic acid (9:1, v/v) solvent system. Conditions for synthesis were optimized to enhance efficiency. Material characterization, conducted via Fourier-transform infrared spectroscopy, scanning electron microscopy, and Brunauer-Emmett-Teller analysis, confirmed the successful formation of the polymer. The MIP demonstrated a maximum adsorption capacity of 1.90 mg/g and a recovery rate of 94.98%, which were significantly higher compared to those of the non-imprinted polymer (0.47 mg/g and 39.67%, respectively). The material exhibited high selectivity for KCZ over structurally similar compounds. A high-performance liquid chromatography method with ultraviolet detection was developed and validated utilizing the synthesized MIP as a selective sorbent. The method displayed excellent linearity over a concentration range of 0.05–500 µg/mL, with a limit of detection of 0.193 µg/g, and a limit of quantification of 0.643 µg/g. These parameters indicate approximately a tenfold enhancement in sensitivity relative to previously reported ultrasound-assisted extraction methods. The method demonstrated excellent precision (relative standard deviation ≤ 6.06%) and high recovery rates (80.41%–98.86%) in real samples. Consequently, this study establishes a cost-effective, selective, and highly efficient approach for the determination of trace levels of KCZ in cosmetic products.