Special Issues-05-02-2019

Click the title above to open the LCGC Europe May 2019 supplement, Recent Developments in HPLC and UHPLC, Volume 32, Number s5, in an interactive PDF format.

Special Issues
Introduction

May 01, 2019

An introduction from the guest editor of this special supplement from LCGC Europe revealing recent developments in high performance liquid chromatography (HPLC) and ultrahigh-pressure liquid chromatography (UHPLC).

This article demonstrates how a user-friendly vacuum-jacketed column (VJC) has been designed without the need of a large internal diameter vacuum chamber and low- and high-vacuum pumps.

Ultrahigh-efficiency separations based on the presence of one deuterium in benzene, toluene, and naphthalene were achieved by recycle chromatography using C18 silica columns. Larger isotopic separation factors, α(H/D), were observed in methanol–water than in acetonitrile–water, when the mobile phases provided similar retention factors (k), or similar methylene selectivity, α(CH2). Isotopic resolutions between nondeuterated and perdeuterated aromatic hydrocarbons at long separation times were estimated by using the plate counts obtainable by recycle operation as a function of a cycle time, along with the retention factors and the separation factors experimentally observed.

Special Issues
Features

May 01, 2019

This article gives a brief overview of the advantages and limitations of recently introduced mathematical procedures such as the Fourier deconvolution of extracolumn effects, iterative curve fitting, multivariate curve resolution, modified power law, and use of first and second derivatives in enhancing resolution. High-throughput analyses in gas chromatography (GC), LC, and supercritical fluid chromatography (SFC) could benefit from these simple and effective approaches in many challenging separations applications.

Characterization of mAbs and related products requires the identification of chromatographic peaks with MS. However, the conventional salt- and pH-gradient elution techniques used in IEX are inherently incompatible with MS. Ammonium acetate- and ammonium carbonate-based mobile phase systems have been recently applied in IEX-MS, but the influence of the eluent composition on peak shape and retention has not been discussed nor studied systematically until now. The aim of the present study was to understand the impact of ionic strength, buffer capacity, and pH-response on the retention behaviour and peak shape of mAb species.