Preparation of polysaccharide-based chiral stationary phases on SiO2@Ag core–shell particles by means of coating and intermolecular polycondensation and comparative liquid chromatography enantioseparations

Surface modified nanoparticles and their applications for enantioselective detection, analysis, and separation of various chiral compounds

The development of efficient enantioselective detection, analysis, and separation relies significantly on molecular interaction. In the scale of molecular interaction, nanomaterials have a significant influence on the performance of enantioselective recognitions. The use of nanomaterials for enantioselective recognition involved synthesizing new materials and immobilization techniques to produce various surface-modified nanoparticles that are either encapsulated or attached to surfaces, as well as layers and coatings. The combination of surface-modified nanomaterials and chiral selectors can improve enantioselective recognition. This review aims to offer engagement insights into the production and application of surface-modified nanomaterials to achieve sensitive and selective detection, better chiral analysis, and separation of numerous chiral compounds.

Recent progress in the development of chiral stationary phases for high-performance liquid chromatography

Separations and analyses of chiral compounds are important in many fields, including pharmaceutical production, preparation of chemical intermediates, and biochemistry. High-performance liquid chromatography using a chiral stationary phase is regarded as one of the most valuable methods for enantiomeric separation and analysis because it is highly efficient, is broadly applicable, and has powerful separation capability. The focus for development of this method is the identification of novel chiral stationary phases with superior recognition performance and good stability. The present article reviews recent progress in the development of new chiral stationary phases for high-performance liquid chromatography between January 2018 and June 2021. These newly reported chiral stationary phases are divided into three categories: small organic molecule-based (cyclodextrin and its derivatives, macrocyclic antibiotics, cinchona alkaloids, and other low molecular weight chiral molecules), macromolecule-based (cellulose and amylose derivatives, chitin and chitosan derivatives, and synthetic helical polymers) and chiral porous material-based (chiral metal-organic frameworks, chiral covalent organic frameworks, and chiral inorganic mesoporous silicas). Each type of chiral stationary phase is discussed in detail.

On-column quantification of amino functionalities bonded to solid porous matrices packed within high performance liquid chromatography columns

Stationary phases (SPs) based on silica matrices functionalized with amino groups linked to their surface through alkyl chains of various length have found remarkable success in performing HILIC separations, showing really effective resolution towards a wide typology of compounds of biological interest, such as carbohydrates, nucleosides, purine and pyrimidine bases. Recently, we developed an operationally simple procedure, named DNBA-M, non-destructive for the analysed SP, designed to quantify the density of basic groups (typically amino groups) chemically bonded to the surface of porous solids. In the present study the DNBA-M procedure has been suitably modified to allow the quantification of any typology of amino groups present on silica matrices packed into HPLC columns. The new approach, named OC-DNBA-M, has been successfully validated through analysis of two HPLC columns packed with aminopropyl-silica matrices. Afterwards, it was also demonstrated as the OC-DNBA-M procedure may allow the effective and in-depth analysis of the structural composition characterizing SPs packed inside HPLC columns, in which amino-groups have been differently and only partially involved in following ureidic functionalizations. It was also proved how the analysed columns can be readily re-employed for the chromatographic applications for which they have been designed, without appreciable deterioration of the respective discrimination abilities.

Chiral Recognition for Chromatography and Membrane-Based Separations: Recent Developments and Future Prospects

With the rapid development of global industry and increasingly frequent product circulation, the separation and detection of chiral drugs/pesticides are becoming increasingly important. The chiral nature of substances can result in harm to the human body, and the selective endocrine-disrupting effect of drug enantiomers is caused by differential enantiospecific binding to receptors. This review is devoted to the specific recognition and resolution of chiral molecules by chromatography and membrane-based enantioseparation techniques. Chromatographic enantiomer separations with chiral stationary phase (CSP)-based columns and membrane-based enantiomer filtration are detailed. In addition, the unique properties of these chiral resolution methods have been summarized for practical applications in the chemistry, environment, biology, medicine, and food industries. We further discussed the recognition mechanism in analytical enantioseparations and analyzed recent developments and future prospects of chromatographic and membrane-based enantioseparations.

Chiral Stationary Phases for Liquid Chromatography: Recent Developments

The planning and development of new chiral stationary phases (CSPs) for liquid chromatography (LC) are considered as continuous and evolutionary issues since the introduction of the first CSP in 1938. The main objectives of the development strategies were to attempt the improvement of the chromatographic enantioresolution performance of the CSPs as well as enlarge their versatility and range of applications. Additionally, the transition to ultra-high-performance LC were underscored. The most recent strategies have comprised the introduction of new chiral selectors, the use of new materials as chromatographic supports or the reduction of its particle size, and the application of different synthetic approaches for preparation of CSPs. This review gathered the most recent developments associated to the different types of CSPs providing an overview of the relevant advances that are arising on LC.