Journal of separation science最新文献

Supercritical fluid chromatography (SFC)-based chiral separation has been considered as one of the green, highly efficient, and precise methods for the resolution of new chiral pharmaceuticals. Herein, a comparative study of chiral separation of afoxolaner on polysaccharide-based chiral stationary phases (CSPs) by SFC and high-performance liquid chromatography (HPLC) has been conducted. First, effects of chromatographic conditions on chiral separation of afoxolaner by SFC, including CSPs, modifier types and ratios, flow rate, column temperature, and back pressure, have been discussed in detail. Cellulose tris(4-methylbenzoate)-coated CSP demonstrated the best separation performance for afoxolaner by SFC with the resolution of 2.37 among five CSPs. Afoxolaner enantiomers were eluted at 3.53 min and 4.54 min under the optimized SFC conditions, respectively, and the total analysis time was less than 6 min, much shorter than that by HPLC. Subsequently, molecular docking studies revealed that hydrogen bonds and halogen bonds formed by afoxolaner and CSPs dominated the selective interaction for the separation of afoxolaner. Additionally, hydrophobic effects and π-π stacks between afoxolaner and chiral selectors enhanced the resolution of afoxolaner. Moreover, quantitative determination results of afoxolaner by SFC showed good linearity relationships (R² > 0.999) between concentration of enantiomers and the corresponding chromatographic peak area in the range from 0.025 to 0.800 mg/mL, and the limit of quantification of enantiomers was 0.025 mg/mL. In brief, SFC separation would offer a green alternative to overcome potential technical bottlenecks in the resolution of new chiral pharmaceuticals.

Countercurrent separation (CCS) is a powerful technique for natural products purification in which the components of the sample are partitioned between two immiscible liquids. Iridoids are natural compounds with remarkable biological and pharmacological activities that have been purified by CCS, with high potential to be scaled up. This review provides CCS fundamentals, a critical consideration of existing studies focused on iridoid purification, and elucidating factors that can improve the processing, such as solvent system selection, processing parameters, and sample pretreatment, which are highly relevant for separation. This review highlights the use of CCS in the purification of iridoids, providing fundamental insights to better understand the CCS technique's contribution to purification improvement. By identifying the process key parameters and addressing issues, the implementation on an industrial scale of CCS for iridoid recovery could be facilitated, with high potential in the food, pharmaceutical, and cosmetic fields.

An efficient strategy was developed for the enrichment of kaempferol-3-O-sophoroside from saffron petal extract. The macroporous resin of XAD-1600N was selected due to its highest adsorption and desorption capacities for kaempferol-3-O-sophoroside. Static adsorption characteristics and dynamic enrichment parameters of this resin were systematically investigated through scientific experiments and analysis. The adsorption characteristics were found to be in good agreement with the pseudo-second-order model, as well as the Freundlich and Langmuir models. The thermodynamics analysis exhibited that this adsorption process was a spontaneous exothermic reaction. Furthermore, the dynamic enrichment for kaempferol-3-O-sophoroside was optimized using a combination of analytical hierarchy process—entropy weight method—response surface methodology, and the comprehensive scores based on desorption rate, recovery rate, and purity. The recommended operation parameters included sample loading rates (2.3–3.7 BV/h), ethanol concentrations (49%–69%), and elution flow rates (1–3 BV/h). After the enrichment process, the purity of kaempferol-3-O-sophoroside from saffron petals extract increased over fivefold after enrichment with acceptable recovery. It is anticipated that this study will contribute to the large-scale development and utilization of kaempferol-3-O-sophoroside from the saffron petals, thereby providing a theoretical basis for natural products enrichment.

The illegal use of β-agonists as feed additives can harm animal-derived food safety. In this study, a detection method for β-agonists in swine urine was established by the combination of azo-linked covalent organic polymer-miniaturized magnetic solid-phase extraction. The main factors that affect the extraction procedure were optimized. The designed adsorbent had good reusability, reproducibility, and stability. Under optimal conditions, the method achieved a good linear correlation coefficient (> 0.99) and a low detection limit (0.01 µg/L). The recoveries of the proposed method in swine urine samples for the simultaneous determination of β-agonists were in the range of 84.3%–99.4%, and the relative standard deviations were less than 6.5%.

The Congming decoction (CMD) is a classic traditional Chinese medicine formula, composed of Poria cocos (Schw.) Wolf, Polygalae Radix, and Acori Tatarinowii Rhizoma. The material basis for the rationality of CMD's compatibility remains unclear in both in vitro and in vivo studies. The relationship between its components and therapeutic efficacy still presents a research gap. Therefore, this study aims to reveal the co-extraction dissolution patterns, metabolic regularity in vitro, and absorption and distribution characteristics in vivo of CMD, thereby exploring the scientific connotation of formulation. Utilizing ultra-high-performance liquid chromatography coupled with quadrupole-orbitrap mass spectrometry technology, a total of 183 constituents were identified in CMD, with 72 recognized as differential compounds before and after combination, suggesting that co-boiling enhances the solubility of active ingredients. In vitro intestinal microbiota results indicated that combination reduced metabolism rates, allowing for greater absorption as the prototype. In vivo analysis identified 62 constituents within rat plasma and tissues; comparing content differences among groups found that the combinations regulate hepatic metabolism and enhance distribution of effective components, potentially serving as a significant material basis for treating Alzheimer's disease (AD). Furthermore, a targeted network pharmacology strategy was established to explore the mechanism of CMD in treating AD. This study clarified the chemical composition, metabolic patterns in vitro, and distribution rules in vivo regarding CMD, and also compared variations before and after composition. It provided new insights into the rationality of CMD's compatibility in the treatment of AD from multiple dimensions and levels.

The quality of quantitative results in bioanalysis requires not only a validated analytical method but also a rigorous estimation of measurement uncertainty. This study examines the challenges associated with the implementation of two distinct approaches in equine anti-doping control for the assessment of uncertainty associated with an ultra-high-performance liquid chromatography-high resolution mass spectrometry quantitative method for caffeine and lidocaine in horse urine. The bottom-up approach, based on the ISO Guide to the Expression of Uncertainty in Measurement (ISO GUM), was compared to the top-down approach using β-content, γ-confidence tolerance intervals (β,γ-CCTI) via F-test. The key limitation of the ISO GUM method was accurately quantifying the various uncertainty components; it gives standardized uncertainty estimates but requires detailed assumptions and modeling about error sources. The direct application of the GUM method imposes the beforehand correction of the matrix effect to provide reliable results. Parallelly, the chemometric approach β,γ-CCTI offers more flexible and realistic estimations. Four combinations of β and γ were investigated to assess their influence on uncertainty interval width: β = 66.7% and 80%; γ = 90% and 95%; and the method was evaluated under repeatability and intermediate precision conditions through the use of advanced computation that adjusts for matrix effects and proves more straightforward for capturing variability inherent in experimental data. The top-down approach is a reliable alternative for routine use and, particularly, for ensuring compliance with regulatory requirements, with the fact that a known proportion β of future results will be within predefined acceptance limits.

The studies have shown that glucosamine (GluN) and mannosamine (ManN) are important nutrients for the formation of chondrocytes, while galactosamine (GalN) is a hepatotoxin with high selectivity. Therefore, the separation and detection of aminosaccharide isomers are of critical significance for pharmaceutical quality monitoring. In this work, a novel method was established for the separation and direct determination of GluN and its isomers (GalN and ManN) based on capillary electrophoresis with amperometric detection. The critical factors affecting electrophoretic separation and electrochemical detection were investigated in detail. Under the optimum conditions, three aminosaccharide isomers and their precursor monosaccharides (glucose, galactose, and mannose) can achieve baseline separation. The limits of detection reached 0.070–0.23 µg/mL (S/N = 3), showing good linearity within two orders of magnitude (R² > 0.99), and the recovery data were in the range of 96.0%-107.8%. This developed method has been applied for the analysis of aminosaccharide pharmaceuticals in different dosage forms. This proposed method is simple to operate, requires no derivatization, and is environmentally friendly, providing an alternative method for the direct determination of aminosaccharides in pharmaceutical formulations. Furthermore, the greenness and eco-friendliness of this developed method were assessed by the green analytical procedure index, analytical greenness, and analytical eco-scale tools.

Adhesives were used by prehistoric humans for attaching a handle to a stone tool, to improve tool use. Remains of these adhesives preserve on stone tools until today. Chemical analysis of these residues is essential for an improved understanding of how humans exploited their natural environment, stone tool manufacturing and use. However, chemical analysis is not straightforward, the highly degraded residue and the precious artefacts impose limitation. In this study a novel (semi-) non-destructive identification technique for prehistoric hafting adhesives is reported; dynamic headspace sampling coupled to comprehensive two-dimensional GC-MS. The dynamic sampling results in a full characterization of the volatile profile of the adhesives. A major advantage is that the whole stone tool, with the adhering adhesive, can be analyzed. Moreover, good results are obtained using only slightly elevated temperatures, which avoids heat damage to the stone tools. Nonetheless, the established biomarkers for prehistoric adhesives are not extracted with this method. Therefore, a non-targeted analytical approach combined with multivariate analysis is utilized. In this approach, the chromatogram of an unknown sample is compared to a database of known samples. In this study a start of an adhesive database is made with 14 different adhesives divided over 4 adhesive classes. The identification capability of this technique is further evaluated using six experimental stone tools, with different adhesives adhered to them and subjected to UV-induced degradation. The large stone pieces could not fit in the automated sampling station, thus, a manual sampling set-up was build. It was found that the sampling strategy did not affect the volatiles extracted and that comparison with the database was possible. The tar samples were the least affected and could be easily identified while the resin samples were more degraded and identification was difficult. This technique is promising for non-destructive adhesive identification on prehistoric stone tools.