Journal of separation science最新文献

This study introduces a green approach to sample preparation by applying natural deep eutectic solvents (NADES) to determine phthalates in carbonated soft drinks using high-performance liquid chromatography with diode array detector (HPLC-DAD). The method employs hollow fiber-microporous membrane liquid-liquid microextraction combined with a 96-well plate system, utilizing fatty-acid-based DES in the pores of the membranes. This methodology substantially reduces the use of organic solvents, and its efficiency is comparable to or better than conventional methods. Fatty acids with chain lengths ranging from 6 to 12 carbons were investigated for the determination of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and benzyl butyl phthalate (BBP). The optimized approach used a NADES of decanoic and nonanoic acids (2:3 molar ratio), with 60 min of extraction and 30 min of desorption in acetonitrile:methanol (1:1 ratio). Limits of detection were reported as 8.2 µg/L for DMP, 7.6 µg/L for DEP and DBP, and 3.0 µg/L for BBP. Intraday precision ranged from 2.2% to 18.6% and inter-day precision from 8.8% to 18.8%. Relative recovery across 3 levels ranged from 83.1% to 113.5%. The methodology was evaluated by two tools with green metrics to indicate sustainability. Analytes are extracted, quantified, and confirmed as phthalates in two brands of carbonated soft drinks.

Disinfection by-products (DBPs) have received considerable focus due to potential teratogenic, carcinogenic, and mutagenic effects; however, there is an evident gap in the availability of analytical methodologies for the simultaneous determination of DBPs in fish, especially iodinated DBPs. This paper developed an innovative analytical method for the simultaneous determination of 12 DBPs, including four trihalomethanes (THMs), three haloacetonitriles, and five iodinated THMs (I-THMs), in fish muscle, utilizing solvent extraction followed by gas chromatography with electron capture detection. The method incorporates tert-butyl methyl ether as an extraction solvent, performing efficient vortex mixing, extraction, and centrifugation under reduced temperature conditions to facilitate the processing of physically disrupted fish tissues. It demonstrates sensitivity with detection limits from 0.21 to 4.02 ng/g, with recoveries from 58.7% to 129.7%. Applied to real fish samples, including bass (n = 7) and carp (n = 7), all contained detectable DBPs, with concentrations between 8.2 and 275.25 ng/g. Significantly, bass from aquaculture facility exhibited the highest contamination, particularly with chlorodiiodomethane at 194.57 ng/g. I-THMs present in all fish samples. Notably, this is the first paper about the analytical protocol of I-THMs in biological matrices. This developed method will facilitate further research on human exposure assessment of DBPs through consumption of fish.

Natural products play a vital role in human health because people find that they can reduce the incidence of many diseases, such as cancer and cardiovascular diseases. Therefore, researchers have developed many effective techniques for screening and separating active compounds from natural products. High-speed countercurrent chromatography is a unique unsupported liquid–liquid chromatography technology that has been widely used in the separation of natural products. In this paper, the research progress of screening and separating active components from natural products by combining high-speed countercurrent chromatography technology with other technologies is reviewed from two aspects: pre-column activity assay and post-column activity assay. The purpose of this paper is to provide some theoretical support for the screening and separation of natural active compounds by high-speed countercurrent chromatography. I hope that the contents summarized in this paper can provide more basis for the development of screening and separation of natural active compounds to realize large-scale preparation.

To achieve specific adsorption-based sample preparation for the poorly soluble veterinary drug oxibendazole, this study employed 4-vinylpyridine as the functional monomer and conducted radical polymerization on the surface of functionalized silica nanoparticles to synthesize a surface molecularly imprinted polymer (OBZMIP). This OBZMIP exhibited good adsorption capacity for oxibendazole within 30 min, with its adsorption behavior conforming to the pseudo–second-order kinetic and Langmuir models, predicting a maximum adsorption capacity of 4.93 mg/g. After five adsorption–desorption cycles, the adsorption capacity remained unchanged, demonstrating excellent reusability. In a mixed system containing eight similar compounds, the selectivity coefficients ranged from 1.3 to 16.9, indicating outstanding specific recognition ability. Utilized as an adsorbent packing material for solid-phase extraction, the prepared OBZMIP demonstrated significantly high recovery rates in the extraction of oxibendazole from four distinct meat samples. Therefore, OBZMIP holds promising applications in the selective extraction of veterinary drug oxibendazole residues during the pretreatment of meat samples.

Nanoplastics (NPs) are emerging water contaminants that threaten human health and ecological security. Developing a method for detecting NPs is significant because of their biological toxicity and mobility. In this study, magnetic solid-phase extraction (MSPE) combined with pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) was used for the pretreatment and qualitative detection of NPs in complex matrices to avoid sample dissolution and eluent usages. The developed methodology can quickly achieve low detection limits in tap and river water, with 0.7283 and 0.6474 µg/L, respectively. To enrich NPs in water, magnetic biochars derived from cornstalks (Fe₃O₄/BCs, i.e., Fe₃O₄/YMG and Fe₃O₄/YMG-ZnCl₂) were conveniently fabricated using activation and coprecipitation methods and employed as adsorbents for MSPE. The results indicated that the incorporation of Fe₃O₄ into BC not only rendered it magnetic but also enhanced the diversity of its surface functional groups and adsorption sites, making it suitable for MSPE. Fe₃O₄/YMG-ZnCl₂ demonstrated excellent extraction and enrichment capacity for polystyrene NPs (PSNPs) over various competitive species. Additionally, it exhibited good resistance to pH and anions, and its reaction mechanism was verified using adsorption kinetics and isothermal models. In addition, after extracting PSNPs from tap and river water using Fe₃O₄/YMG-ZnCl₂, they were successfully qualitatively analyzed by Py-GC/MS.

Researches regarding quality control of ginseng focusing on the lipids are rare. Herein, ultra-high-performance supercritical fluid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (UHPSFC/IM-QTOF-MS) combined with untargeted metabolomic analysis was utilized to holistically characterize and compare the lipidomic difference among 12 Panax-derived herbal medicines. The established UHPSFC/IM-QTOF-MS method, using a Torus 1-AA column with CO₂/CH₃OH (modifier) as the mobile phase, well resolved the ginseng lipidome within 30 min. The lipid isomers and those easily co-eluted by conventional reversed-phase chromatography got separated, and integrated analyses of the positive-/negative-mode MS data and IM-derived collision cross section (CCS) greatly enhanced lipids identification. By the pattern recognition chemometric analysis of 90 batches of ginseng samples, the root ginseng samples showed significant differences in lipidome composition from those stem/leaf and flower samples. In contrast, red ginseng also contained lipids significantly different from the other root ginseng. Totally 82 potential differential lipids were discovered and identified based on the positive-mode data and 90 ones in the negative mode. Some of these lipid markers might be diagnostic for their authentication. Conclusively, we first report the lipidomic difference among 12 ginseng varieties, and the information obtained can lay foundation for the accurate identification of ginseng from the lipidome level.

In this work, Guizhi Fuling Formula (GFF), as well as α_1A-adrenergic receptor (α_1A-AR) were taken as the research objects. By utilizing the ultra-affinity between Colicin L7 DNase (CL7) and its homologous immune protein 7 (Im7), CL7-tagged α_1A-AR was oriented immobilized to the Im7-coated silica gel surface. With the α_1A-AR immobilized column in hand, the active compounds in GFF targeted to α_1A-AR were screened, and the binding procedures were analyzed. The composite characterization demonstrated that the α_1A-AR can be immobilized to the chromatographic stationary phase with good specificity and stability in 3 weeks. Paeoniflorin, cinnamic acid, and paeonol were identified as the active compounds in GFF targeted to α_1A-AR. Among them, cinnamic acid and paeonol have the same binding site on α_1A-AR as the specific drug tamsulosin. The binding parameters obtained by frontal analysis and injection amount-dependent analysis were consistent in the same concentration range. Collectively, these results indicated that the α_1A-AR chromatographic column synthesized by a novel immobilized method was capable of screening and analyzing the functional compounds from the complex matrix, which provided an alternative for rapid screening and analysis to traditional ethnic drugs.

Antimicrobial peptides (AMPs) are excellent promising candidates for biomedical applications owing to their structural properties, high biocompatibility, good biodegradability, and functional diversity. Unlike conventional antibiotics, AMPs have been shown to have broad-spectrum antimicrobial activity toward Gram-positive/negative bacteria, as well as antifungal and antiviral activity. These peptides have also been found to be cytotoxic to sperm and cancer cells. A range of AMPs has been isolated from various organisms, such as bacteria, fungi, plants, and animals. This review summarizes the latest studies on AMPs, covering their isolation, purification, and characterization as well as their potential biomedical applications and beyond.