色谱最新文献

Carbon dioxide (CO₂) absorption and capture is an effective measure to achieve the "dual carbon" goal of carbon peak and carbon neutrality in China. Organic amine compounds are widely used in the industrial separation and recovery of CO₂. Thus, the establishment of analytical methods for organic amine compounds is of great significance for the research and development of carbon capture and storage (CCS) technology and carbon capture, utilization and storage (CCUS) technology. In this study, a method was developed for the determination of nine organic amine compounds in CO₂ absorption liquid by hydrophilic interaction liquid chromatography (HILIC)-electrostatic field orbitrap high resolution mass spectrometry. The sample was diluted with water and filtered through a 0.22 μm nylon membrane before sampling and analysis. An Accucore HILIC column (100 mm×2.1 mm, 2.6 μm) was used for separation at 30 ℃. Gradient elution was conducted using 90% acetonitrile aqueous solution containing 5 mmol/L ammonium formate and 0.1% formic acid as mobile phase A and 10% acetonitrile aqueous solution containing 5 mmol/L ammonium formate and 0.1% formic acid as mobile phase B. Determination was performed using an electrospray ion source (ESI) in the positive ion mode. The quantitative analysis was carried out by standard addition method. The chromatographic retention performance of different chromatographic columns and the influence of different mobile phases on the separation of the organic amine compounds were compared, and the method was validated. The results showed that the linear ranges of the nine organic amine compounds were 0.04-25000 ng/mL with the linear correlation coefficients (R²) greater than 0.9910. The limits of detection (LODs) of the method were in the range of 0.0004-0.0080 ng/mL, and the limits of quantification (LOQs) of the method were in the range of 0.0035-0.0400 ng/mL. The average recoveries of the method ranged from 85.30% to 104.26% with relative standard deviations (RSDs) of 0.04%-7.95% at the spiked levels of 1, 1.5 and 3 times sample concentration. The established method was applied to detect the absorption waste liquid of a cement plant, and nine organic amine compounds could be effectively detected. The stability of the actual sample was tested, and the RSDs were 0.10%-6.35% in 48 h at 4 ℃. The method is sensitive, rapid and accurate for the determination of the nine organic amine compounds in industrial waste water. It can provide reference for the detection of organic amine compounds, and provide strong technical support for the research and industrial application of CO₂ capture technology.

Excessive sugar consumption is associated with metabolic health problems. Rare sugars are gradually being used as substitutes for sugar, and their consumption is increasing daily, raising food-safety issues such as false advertising, adulteration, and overdosing. The determination of rare-sugar compounds has attracted considerable attention in recent years. However, no standard method for the simultaneous determination of six rare sugars (allulose, tagatose, trehalose, isomaltulose, erythritol, and mannitol) in solid foods is available. Therefore, establishing a suitable analytical method for these sugars is necessary. In this study, high performance liquid chromatography coupled with evaporative light-scattering detection was used to determine rare sugars in solid foods. The optimum chromatographic and detector conditions were determined by evaluating the instrument parameters. Analysis was carried out on a Zorbax Original NH₂ column (250 mm×4.6 mm, 5 μm) via flow-rate gradient elution (0-15 min, 1.0 mL/min; 15-18 min, 1.0-2.0 mL/min; 18-25 min, 2.0 mL/min) with acetonitrile-water (80∶20, v/v) as the mobile phase. Sharp and symmetric chromatographic peaks were obtained under these conditions. The resolutions for all the six rare sugars were greater than 1.5. Optimization of the evaporative light-scattering detector was extremely important to the responses of the rare-sugar compounds. The two most significant parameters were the nebulizer carrier gas flow rate and drift tube temperature. The detection system was operated under the following conditions: the drift tube temperature was set to 50 ℃, the nebulizer carrier gas was high-purity nitrogen, the carrier gas flow rate was 1.0 mL/min, the nitrogen pressure was regulated to 275.79 kPa, and the gain factor was set to 3. The sample was extracted with 25 mL of water, shaken and vortexed for 10 min, purified with 200 μL of zinc acetate solution and 200 μL of potassium ferricyanide solution, and centrifuged at 4500 r/min for 10 min. Next, 1 mL of the supernatant was passed through a 0.22 μm aqueous-phase filter membrane, and the filtrate obtained was analyzed using the evaporative light-scattering detector. The six rare sugars were quantitatively analyzed using the external standard method and showed good linearity with coefficients of determination (R²) greater than 0.9985. The limits of detection and quantification were 0.020-0.60 and 0.60-1.8 g/100 g, respectively. In addition, when blank solid food samples were spiked with the analytes at three levels, the average recoveries of the six rare sugars were 92.6%-103.2%, with relative standard deviations (RSDs) of 0.7%-4.4%. An RSD of <5% indicated that the method had good precision. Interference experiments were performed to determine whether the sugars and artificial sweeteners commonly found in solid foods affected the targets. The method established in this study was used to analyze the contents of the six rare

Hydrogel microfibers, which are characterized by flexible mechanical properties, a uniform spatial distribution, large surface areas, and excellent biocompatibility, hold great potential for various biomedical applications. However, the fabrication of heterogeneous hydrogel microfibers with high cell-loading capacity and the ability to carry multiple components via an environmentally friendly method remains challenging. In this study, we developed a novel pneumatic pump-assisted all-aqueous microfluidic system that enables the one-step fabrication of all-aqueous droplet-filled hydrogel microfibers with unique morphologies and adjustable configurations. By designing a pump-valve cycling system and selecting two immiscible fluids with stable water interfaces (dextran and polyethylene glycol), we successfully fabricated alginate microfibers with equidistantly arranged droplets through the ionotropic gelation reaction between sodium alginate and calcium chloride. The droplet size, interdroplet spacing, and microfiber dimensions could be flexibly controlled by adjusting the flow rates of the inner-phase, middle-phase, and outer-phase inlets. The results showed that the system enabled the high-throughput in situ formation of functional three-dimensional cell spheroids. The generated cell spheroids exhibited excellent cell viability and drug-testing functionality, indicating their potential applications in cell cultures. The developed technique offers strong support for future biomedical research and applications, and provides a new approach for the preparation of multifunctional hydrogel microfibers for materials science, tissue engineering, and drug testing.