School of Chemistry and Chemical Engineering, Southwest University, Beibei, Chongqing, 400715, PR China.
School of Chemistry and Chemical Engineering, Southwest University, Beibei, Chongqing, 400715, PR China.
Anal Chim Acta. 2024 Sep 8;1321:343018. doi: 10.1016/j.aca.2024.343018. Epub 2024 Jul 24.
Food safety has become an essential aspect of public concern and there are lots of detection means. Liquid chromatography plays a dominating role in food safety inspection because of its high separation efficiency and reproducibility. However, with the increasing complexity of real samples and monitoring requirements, conventional single-mode chromatography would require frequent column replacement and cannot separate different kinds of analytes on a single column simultaneously, which is costly and time-consuming. There is a great need for fabricating mixed-mode stationary phases and validating the feasibility of employing mixed-mode stationary phases for food safety inspection.
This work fabricated multifunctional stationary phases for liquid chromatography to determine diverse food additives under the mixed mode of RPLC/HILIC/IEC. Two dicationic ionic liquid silanes were synthesized and bonded onto the silica gel surface. The functionalized silica was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and elemental analysis. Both columns provide satisfactory separation performance towards 6 hydrophilic nucleosides, 4 hydrophobic polycyclic aromatic hydrocarbons, and 5 anions. Great repeatability of retention (RSD <0.1 %) and column efficiency (100330 plate/m) were obtained. Thermomechanical analysis and linear solvation energy relationship investigated the retention mechanism. Finally, the better in two prepared columns was employed to separate and determine the contents of NO and NO in vegetables(highest 4906 mg kg NO in spinach), preservatives in bottled beverages (180.8 mg kg sodium benzoate in soft drink), and melamine in milk with satisfactory performance and recovery rates ranging from 96.4 % to 105.6 %.
This work developed a novel scheme for preparing mixed-mode stationary phases by dicationic ionic liquid which provides great separation selectivity. Most importantly, this work proved the superiority of employing mixed-mode stationary phases for food safety inspection, which might avoid high-cost and frequent changes of columns and chromatography systems in the near future.
食品安全已成为公众关注的重要问题，有许多检测手段。由于其高分离效率和重现性，液相色谱在食品安全检测中发挥着主导作用。然而，随着实际样品和监测要求的日益复杂，传统的单模式色谱需要频繁更换色谱柱，并且不能在单个色谱柱上同时分离不同种类的分析物，这既昂贵又耗时。因此，非常需要制备混合模式固定相，并验证采用混合模式固定相进行食品安全检测的可行性。
本工作制备了用于液相色谱的多功能固定相，以在反相色谱/亲水相互作用色谱/离子交换模式下测定多种食品添加剂。合成了两种二价离子液体硅烷并键合到硅胶表面。功能化硅胶通过傅里叶变换红外光谱、X 射线光电子能谱和元素分析进行了表征。两种色谱柱均对 6 种亲水性核苷、4 种疏水性多环芳烃和 5 种阴离子提供了满意的分离性能。保留的重现性（RSD<0.1%）和柱效（100330 板/m）均很好。热机械分析和线性溶剂化能量关系研究了保留机制。最后，在所制备的两种色谱柱中选择更好的一种分离和测定蔬菜中 NO 和 NO 的含量（菠菜中最高 4906mg/kg 的 NO）、瓶装饮料中的防腐剂（软饮料中 180.8mg/kg 的苯甲酸钠）和牛奶中的三聚氰胺，具有令人满意的性能和回收率在 96.4%至 105.6%之间。
本工作开发了一种通过二价离子液体制备混合模式固定相的新方案，该方案提供了很大的分离选择性。最重要的是，本工作证明了采用混合模式固定相进行食品安全检测的优越性，这可能在不久的将来避免高成本和频繁更换色谱柱和色谱系统。
