No abstract

In this study, diamino moiety functionalized silica nanoparticles with the size of 118 ± 12 nm were successfully synthesized and directly introduced into a chiral capillary electrophoresis system to improve the enantioseparation of 9-fluorenyl methoxycarbonyl derivatized amino acids using norvancomycin as chiral selector. Under acidic background electrolyte conditions, functional silica nanoparticles can be readily adsorbed onto the inner surface of bare silica capillary column through electrostatic interaction to form a dynamic coating, resulting in a reversed anodic electro-osmotic flow (i.e. from cathode to anode). As expected, chiral amino acid derivatives (usually negatively charged) can be rapidly separated under co-electro-osmotic flow conditions in the current separation system. Furthermore, the column performance and detection sensitivity for the enantioseparation were also obviously improved because the adsorption of chiral selector of norvancomycin to the capillary wall was greatly suppressed. Some important factors influencing the separation, such as the coating thickness, background electrolyte concentration, functional silica nanoparticles concentration, and the organic modifier were also investigated and the optimized separation conditions were obtained.

Chirality is one of the intrinsic attributes of the nature. Chiral separation and analysis are of great importance in many research fields, such as life science, environmental science, biological engineering and pharmaceutical engineering. Currently, chiral capillary electrophoresis technique used for the enantioselective resolution of different kinds of racemates has become one of the most distinctive research and application fields. However, the adsorption of the analytes (or chiral selectors) on the inner wall of the capillary is a common problem in capillary electrophoresis chiral separation. Coating technology, namely modification of the inner wall of the capillary, is the simplest and most effective way to suppress disadvantageous adsorption, and to improve the separation efficiency and analysis repeatability. In this review, the recent applications of different coating procedures in chiral analysis are presented, and the future developments in this field are also prospected.

In this work, a simple, facile, and sensitive magnetic solid-phase extraction method was developed for the extraction and enrichment of three representative steroid hormones before high-performance liquid chromatography analysis. Gold-modified Fe O nanoparticles, as novel magnetic adsorbents, were prepared by a rapid and environmentally friendly procedure in which polydopamine served as the reductant as well as the stabilizer for the gold nanoparticles, thus successfully avoiding the use of some toxic reagents. To obtain maximum extraction efficiency, several significant factors affecting the preconcentration steps, including the amount of adsorbent, extraction time, pH of the sample solution, and the desorption conditions, were optimized, and the enrichment factors for three steroids were all higher than 90. The validity of the established method was evaluated and good analytical characteristics were obtained. A wide linearity range (0.8-500 μg/L for all the analytes) was attained with good correlation (R ≥ 0.991). The low limits of detection were 0.20-0.25 μg/L, and the relative standard deviations ranged from 0.83 to 4.63%, demonstrating a good precision. The proposed method was also successfully applied to the extraction and analysis of steroids in urine, milk, and water samples with satisfactory results, which showed its reliability and feasibility in real sample analysis.

Ｆｏｕｎｄａｔｉｏｎ ｉｔｅｍ： Ｎａｔｉｏｎａｌ Ｎａｔｕｒａｌ Ｓｃｉｅｎｃｅ Ｆｏｕｎｄａｔｉｏｎ ｏｆ Ｃｈｉｎａ (Ｎｏ． ２１００５０５４) ； Ｓｔａｔｅ Ｋｅｙ Ｌａｂｏｒａｔｏｒｙ ｏｆ Ｍｅｄｉｃｉｎａｌ Ｃｈｅｍｉｃａｌ Ｂｉｏｌｏｇｙ (Ｎｏ． ２０１６０３００４) ． 聚多巴胺表面改性技术在分离科学领域中的应用 柴微波 １ ， 王会娟 １ ， 安学涵 １ ， 丁国生 １，２，３ *