Controllable preparation of a hydrophilic/ion‐exchange mixed‐mode stationary phase by surface‐initiated atom transfer radical polymerization using a mixture of two functional monomers

Recent applications of retention modelling in liquid chromatography (2015–2020) are comprehensively reviewed. The fundamentals of the field, which date back much longer, are summarized. Retention modeling is used in retention‐mechanism studies, for determining physical parameters, such as lipophilicity, and for various more‐practical purposes, including method development and optimization, method transfer, and stationary‐phase characterization and comparison. The review focusses on the effects of mobile‐phase composition on retention, but other variables and novel models to describe their effects are also considered. The five most‐common models are addressed in detail, i.e. the log‐linear (linear‐solvent‐strength) model, the quadratic model, the log–log (adsorption) model, the mixed‐mode model, and the Neue–Kuss model. Isocratic and gradient‐elution methods are considered for determining model parameters and the evaluation and validation of fitted models is discussed. Strategies in which retention models are applied for developing and optimizing one‐ and two‐dimensional liquid chromatographic separations are discussed. The review culminates in some overall conclusions and several concrete recommendations.

Section: Methodsmentioning

confidence: 99%

Recent applications of retention modelling in liquid chromatography

Uijl

Schoenmakers

Pirok

et al. 2020

“…Most recently, the above mentioned authors grafted a mixture of two different monomers, glycidyl methacrylate, and 2‐dimethylaminoethylmethacrylate, onto the silica via the same protocol with the goal to obtain HILIC/anion‐exchange sorbent . The retention of various analytes was found to change with the ratio of the two monomers.…”

Section: Hybrid Mixed‐mode Stationary Phasesmentioning

confidence: 99%

Recent advances in mixed‐mode chromatographic stationary phases

Sýkora

Řezanka

Záruba

et al. 2018

Mixed‐mode phases have become very popular in the last decade, and the number of new mixed/multi‐mode sorbents is growing fast. Unlike single‐mode stationary phases, perfectly suited for the separation of the analytes possessing similar physicochemical properties, for instance reversed‐phase chromatography for hydrophobic solutes, mixed‐mode sorbents providing multimodal interactions can render better separation selectivity for complex mixtures of solutes differing significantly in their physicochemical characteristics. The most frequent modern mixed‐mode stationary phases are di/tri‐mode sorbents embracing the following interactions, hydrophobic, electrostatic (coulombic), and hydrophilic. According to their structures, it is possible to distinguish silica‐based, polymer‐based, hybrid, and monolithic mixed‐mode stationary phases. Herewith, newly synthesized mixed‐mode sorbents developed within the last two and half years are categorized, discussed, and summarized. The main attention is devoted to the description of the synthetic routes and characterization methods applied for the new stationary phases.

“…IEC and RPLC . Subsequently, mixed‐mode stationary phases prepared by SI‐ATRP were also reported . For instance, vinyltetrazole was grafted onto polymer beads by SI‐ATRP to obtain a hydrophilic interaction/cation‐exchange stationary phase for the separation of proteins .…”

Section: Introductionmentioning

confidence: 99%

Preparation and evaluation of diblock copolymer‐grafted silica by sequential surface initiated‐atom transfer radical polymerization for reverse‐phase/ion‐exchange mixed‐mode chromatography

Wang

Wei

2017

Self Cite

A novel approach that involved the grafting of diblock copolymer with two types of monomer onto substrate by sequential surface initiated-atom transfer radical polymerization was proposed to prepare a mixed-mode chromatographic stationary phase. The distinguishing feature of this method is that it can be applied in the preparation of various mixed-mode stationary phases. In this study, a new reverse-phase/ion-exchange stationary phase was prepared by grafting hydrophobic styrene and cationic sodium 4-styrenesulfonate by the proposed approach onto silica surface. The chromatographic properties of the prepared stationary phase were evaluated by the separation of benzene derivatives, anilines, and β-agonists, and by the effect of pH values and acetonitrile content on the retention. Compared with typical RP columns, the prepared stationary phase achieved the better resolution and higher selectivity at a shorter separation time and lower organic content. Moreover, the application of the prepared column was proved by separating widely distributed polar and charged compounds simultaneously.