Special Issues June 2017

June 2017 | Volume 30, Issue 6
Introduction
An introduction from the guest editor of this special supplement from LCGC Europe and LCGC North America revealing recent developments in high performance liquid chromatography (HPLC) and ultrahigh-pressure liquid chromatography (UHPLC).
Features
In the 21st century, numerous advances have been made in liquid chromatography (LC) column technology. The best known are columns packed with sub-2-µm porous particles or sub-3-µm superficially particles, and monolithic columns. Another very novel and original development is micro-pillar array columns (µPAC). µPACs are produced by a lithographic etching process to create a perfectly ordered separation bed on a silicon chip. Although the performance in terms of efficiency has been illustrated, the applicability for analysis of real complex samples has yet to be fully demonstrated. This article illustrates that state‑of‑the‑art µPAC columns coated with octadecyl are applicable for a challenging application such as lipidomics. The performance is illustrated with the analysis of human blood plasma lipids.
Mixed-mode high performance liquid chromatography (MM-HPLC) involves the combined use of two (or more) retention mechanisms in a single chromatographic system. Many original stationary phases have been proposed in recent years with promising possibilities, while applications have only started to appear in the literature. In this review, the authors discuss mixed-mode chromatography stationary phases. An overview of applications using mixed-mode chromatography is described, as well as the increased interest in mixed-mode systems for two-dimensional chromatography.
Enantioselective high performance liquid chromatography (HPLC) is slowly adopting the modern particle technologies (sub-2-µm fully porous particles [FPPs] and sub-3-µm superficially porous silica particles [SPPs]) that have been well known in reversed-phase LC for the past decade. The most significant benefit is that enantiomer separations can be performed much faster, which is of interest in high-throughput screening applications and multidimensional enantioselective HPLC analysis. The state of the art is briefly discussed with some examples documenting the potential of core–shell particle technology and comprehensive multidimensional separations.
The aim of this article is to illustrate the current status of computer-assisted method development and retention modelling. This study focuses on the successful method development of typical small pharmaceutical compounds (impurity profiling) and large therapeutic proteins. By choosing appropriate initial conditions, the method development can be performed in less than one day. However, for small molecules possessing different physicochemical properties, the conditions can be multifarious, while for biopharmaceuticals (for example, monoclonal antibodies [mAbs], antibody–drug conjugates [ADCs]), a generic method can easily be developed. In addition to retention modelling and optimization, the potential of simulated robustness testing is also demonstrated. Depending on the applied retention model, the impact of any change among six experimental parameters (tG, T, pH, ternary composition, flow rate, and initial- and final mobile phase compositions) on the separation can be assessed using a 26 or 36 type virtual
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