LCGC Asia Pacific-11-01-2018

LCGC Asia Pacific

Vol 21 No 4 LCGC Asia Pacific November/December 2018 Regular Issue PDF

November 01, 2018

Issue PDF

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Click the title above to open the LCGC Asia Pacific November 2018 regular issue in an interactive PDF format.

Pressure Tuning: Increasing the Flexibility of Comprehensive Two-Dimensional Gas Chromatography

November 01, 2018

Features

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Comprehensive two-dimensional gas chromatography (GC×GC) offers significant improvement for volatile chemical separation. Selecting suitable first (1D) and second dimension (2D) columns normally requires consideration of the chemical composition of a sample. Replacing one of these dimensions with a two-column ensemble (for example, 1D1 + 1D2 for the 1D column), provided with a pressure tuning makeup gas between them, varies the relative retentions of compounds before the modulation step according to the junction pressure. This makes it possible to alter the apparent polarity of the 1D ensemble, and this alters peak positions in the 2D GC×GC space. This article presents an account of studies that suggest this offers potential for improved operation for a GC×GC laboratory.

Analyzing Phosphorylated N-Glycans with Full Recovery on Bio-Inert LC Systems and PEEK-Lined HILIC Columns

November 01, 2018

Cover Story

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Glycosylation is a critical quality attribute (CQA) that can impact on product safety and efficacy of protein biopharmaceuticals. Characterization of N-glycans is therefore of paramount importance for the pharmaceutical industry. Hydrophilic interaction liquid chromatography (HILIC) combined with fluorescence detection (FLD) and 2-aminobenzamide (2-AB) labelling is the golden standard for the analysis of N-glycans enzymatically liberated from biopharmaceuticals. However, for phosphorylated N-glycans, that is, those attached on lysosomal enzymes, irreproducible data and recovery issues are observed on conventional liquid chromatography (LC) instrumentation and columns, which can be attributed to the interaction of the phosphate moieties with stainless steel components in the flow path. This article demonstrates the analysis of phosphorylated glycans with full recovery on a bio-inert LC system and PEEK-lined HILIC column.

Highlights from the HPLC 2018 Symposium

November 01, 2018

Columns

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The 47th International Symposium on High Performance Liquid Phase Separations and Related Techniques (HPLC 2018), chaired by Norman Dovichi, was held from 29 July to 2 August in Washington, D.C., USA. This instalment of “Column Watch” covers some of the highlights observed at the symposium. In addition, trends and perspectives on future developments in HPLC noted from the conference are presented.