色谱最新文献

Hypercrosslinked porous organic polymers (HCPs), a novel type of porous materials synthesized via the Friedel-Crafts reaction, are widely used in gas storage, heterogeneous catalysis, chromatographic separation, and organic pollutant capture. HCPs have the advantages of a wide monomer source, low cost, mild synthesis conditions, and easy functionalization. In recent years, HCPs have shown great application potential in solid phase extraction. Given their high specific surface area, excellent adsorption properties, diverse chemical structures, and easy chemical modification, HCPs have been successfully applied to the extraction of different types of analytes with efficient extraction performance. Based on the chemical structure of HCPs, their target analytes, and the adsorption mechanism, HCPs can be classified as hydrophobic, hydrophilic, and ionic species. Hydrophobic HCPs are usually constructed as extended conjugated structures by overcrosslinking aromatic compounds as monomers. Common monomers include ferrocene, triphenylamine, triphenylphosphine, etc. This type of HCPs shows good adsorption effects on nonpolar analytes such as benzuron herbicides and phthalates through strong π-π and hydrophobic interactions. Hydrophilic HCPs are prepared by introducing polar monomers or crosslinking agents, or by modifying polar functional groups. This type of adsorbent is commonly used to extract polar analytes such as nitroimidazole, chlorophenol, tetracycline, etc. In addition to hydrophobic forces, polar interactions, such as hydrogen-bonding and dipole-dipole interactions, also occur between the adsorbent and analyte. Ionic HCPs are mixed-mode solid phase extraction materials formed by introducing ionic functional groups into the polymer. Mixed-mode adsorbents usually have a dual reversed-phase/ion-exchange retention mechanism, which helps control the retention behavior of the adsorbent by adjusting the elution strength of the eluting solvent. In addition, the extraction mode can be switched by controlling the pH of the sample solution and eluting solvent. In this manner, matrix interferences can be removed while the target analytes are enriched. Ionic HCPs present a unique advantage in the extraction of acid-base drugs in water. The combination of new HCP extraction materials with modern analytical techniques, such as chromatography and mass spectrometry, has been widely used in environmental monitoring, food safety, and biochemical analyses. In this review, the characteristics and synthesis methods of HCPs are briefly introduced, and the application progress of different types of HCPs in cartridge-based solid phase extraction is described. Finally, the future outlook of HCP applications is discussed.

Covalent organic frameworks (COFs) are a type of crystalline porous polymers. It firstly prepared by thermodynamically controlled reversible polymerization to obtain chain units and connecting small organic molecular building units with a certain symmetry. These polymers are widely used in gas adsorption, catalysis, sensing, drug delivery, and many other fields. Solid-phase extraction (SPE) is a fast and simple sample pretreatment technology that can enrich analytes and improve the accuracy and sensitivity of analysis and detection; it is extensively employed in food safety detection, environmental pollutant analysis, and several other fields. How to improve the sensitivity, selectivity, and detection limit of the method during sample pretreatment have become a topic of great interest. COFs have recently been applied to sample pretreatment owing to their low skeleton density, large specific surface area, high porosity, good stability, facile design and modification, simple synthesis, and high selectivity. At present, COFs have also attracted extensive attention as new extraction materials in the field of SPE. These materials have been applied to the extraction and enrichment of diverse types of pollutants in food, environmental, and biological samples, such as heavy metal ions, polycyclic aromatic hydrocarbons, phenol, chlorophenol, chlorobenzene, polybrominated diphenyl ethers, estrogen, drug residues, pesticide residues, etc. COFs can be synthesized from different materials and exert different effects on different extracts. New types of COFs can also be synthesized via modification to achieve better extraction effects. In this work, the main types and synthesis methods of COFs are introduced, and the most important applications of COFs in the fields of food, environment and biology in recent years are highlighted. The development prospects of COFs in the field of SPE are also discussed.

Bisphenols are endocrine disruptors that are characterized with bioaccumulation, persistence, and estrogenic activity. Even low contents of bisphenols can exert adverse effects on human health and the ecological environment. Herein, a method combining accelerated solvent extraction and solid-phase extraction purification with ultra performance liquid chromatography-tandem mass spectrometry was developed for the accurate detection of bisphenol A (BPA), bisphenol B (BPB), bisphenol F (BPF), bisphenol S (BPS), bisphenol Z (BPZ), bisphenol AF (BPAF), and bisphenol AP (BPAP) in sediments. The mass spectrometric parameters of the seven bisphenols were optimized, and the response values, separation effects, and chromatographic peak shapes of the target compounds were compared under three different mobile phase conditions. The sediment samples were pretreated by accelerated solvent extraction, and orthogonal tests were used to optimize the extraction solvent, extraction temperature, and cycle number. The results showed that the use of 0.05% (v/v) ammonia and acetonitrile as the mobile phase for gradient elution could rapidly separate the seven bisphenols on an Acquity UPLC BEH C₁₈ column (100 mm×2.1 mm, 1.7 μm). The gradient program was as follows: 0-2 min, 60%A; 2-6 min, 60%A-40%A; 6-6.5 min, 40%A; 6.5-7 min, 40%A-60%A; 7-8 min, 60%A. Orthogonal experiments indicated that the optimal extraction conditions were as follows: extraction solvent of acetonitrile, extraction temperature of 100 ℃, and cycle number of three. The seven bisphenols showed good linearity in the range of 1.0-200 μg/L, with correlation coefficients (r²) greater than 0.999, and the limits of detection were 0.01-0.3 ng/g. The recoveries for the seven bisphenols ranged from 74.9% to 102.8% at three spiking levels (2.0, 10, 20 ng/g), with relative standard deviations ranging from 6.2% to 10.3%. The established method was applied to detect the seven bisphenols in sediment samples collected from Luoma Lake and its inflow rivers. BPA, BPB, BPF, BPS, and BPAF were detected in the sediments of the lake, and BPA, BPF, and BPS were detected in the sediments of its inflow rivers. The detection frequency of BPA and BPF was 100%, and the contents of these bisphenols in the sediment were 11.9-38.0 ng/g and 11.0-27.3 ng/g, respectively. The developed method is simple, rapid with high accuracy and precision, and is suitable for the determination of the seven bisphenols in sediment.