Recent contributions for improving sensitivity in chiral CE

Abstract

The flexibility and versatility of the chiral CE are unrivaled and the same instrumentation can be used to separate a diverse range of analytes, both large and small molecules, whether charged or uncharged. However, one of the disadvantages is generally thought to be the poor sensitivity of ultraviolet (UV) detection, which is the most popular among CE detectors. This review focuses on methodologies and applications regarding improvements of sensitivity in chiral CE published in the last 2 years (June 2015 until May 2017). This contribution continues to update this series of biannual reviews, first published in Electrophoresis in 2006. The main body of the review brings a survey of publications organized according to different approaches to detect a low amount of analytes, either by sample treatment procedures or by in-capillary sample preconcentration techniques, both using UV detection, or even by employing detection systems more sensitive than UV absorption, such as LIF or MS. This review provides comprehensive tables listing the new approaches in sensitive chiral CE with categorizing by the fundamental mechanism to enhance the sensitivity, which provide relevant information on the strategies employed. The concluding remarks in the final part of the review evaluate present state of art and the trends for sensitivity enhancement in chiral CE.

Recent progress of sample stacking in capillary electrophoresis (2016–2018)

“…During the reviewed period, no other methodological review on electrophoretic sample stacking appeared; the below mentioned reviews have broader or narrower scopes, or are focused on specific aspects. General reviews were aimed at enrichment techniques and enhancement of sensitivity in CE , their application in chiral CE , in CE‐MS and in the analysis of alkaloids . Electrophoretic stacking was also included in specialized reviews on CE analyses of peptides and proteins , pharmaceuticals , pesticides , antibiotics , food , and biologically important thiols .…”

Chiral Capillary Electrokinetic Chromatography: Principle and Applications, Detection and Identification, Design of Experiment, and Exploration of Chiral Recognition Using Molecular Modeling

“…Laser-induced fluorescence (LIF) detection did not show popularity in CEKC, due to the drawback of the molecular labeling used for enantiomeric drug derivatization. Degradation products of the fluorophores can generate fluorescent side products, which can interfere with the detection signal of the labeled low concentration target enantiomer [ 120 , 121 ].…”

A Two-Dimensional Affinity Capture and Separation Mini-Platform for the Isolation, Enrichment, and Quantification of Biomarkers and Its Potential Use for Liquid Biopsy

“…Promisingly, efforts to improve the analytical sensitivity of CE thus far have led to successful improvements in the limits of detection of substances found at low concentrations. Some of these methods include field-amplified sample stacking, large-volume sample stacking, pH-mediated sample stacking, on-column isotachophoresis, chromatographic preconcentration, sample stacking for micellar electrokinetic chromatography, sweeping, and derivation of analytes with fluorescent chromophores [ 25 , 47 , 54 , 55 , 61 , 62 , 63 , 64 , 65 , 66 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 ]. One technology in particular is the combination of solid-phase extraction methods, using affinity-based ligands, with CE.…”