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Peak Scientific has partnered with Molecular Science Corporation to supply nitrogen gas generation systems on their first mobile laboratory aimed at rapidly expanding the cannabis testing and research sector.

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This article presents two case studies regarding the characterization of protein-DNA complexes using two complementary multi-angle light scattering (MALS) techniques, namely size-exclusion chromatography (SEC–MALS) to determine absolute molar mass of each component, and composition-gradient MALS (CG–MALS) to quantify stoichiometry and affinity at binding sites in solution.

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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.

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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.

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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.

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Supercritical fluid chromatography (SFC) and hydrophilic interaction liquid chromatography (HILIC) are suitable for screening very polar trace organic compounds in environmental water samples. The polarity range of separable compounds in SFC is as broad as the polarity range of the serial coupling of reversed‑phase liquid chromatography and HILIC (reversed-phase LC–HILIC). In this article the orthogonality of SFC and reversed-phase LC–HILIC is assessed. It is shown that both techniques are highly orthogonal and complementary. The parallel use of the two techniques offers additional benefits for the compound monitoring of, for example, pharmaceuticals in surface waters, or the identification of unknown compounds in complex samples.

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“The column is the heart of the separation.” Perhaps more accurately, the column is where the chemistry that generates a separation happens. For chemists and non-chemists alike, the chemistry that drives the utility of a column to solve a separation problem can be complex and confusing. Selectivity describes the ability of a column to effect a separation. This instalment of “GC Connections” focuses on selectivity, its definition, and its importance for generating separations and resolution. We will also see how selectivity is the concept that underlies the idea of column polarity. We begin by asking two simple questions about common observations, then extend these observations into a capillary gas chromatography (GC) column, and conclude with an introduction to methods for evaluating the quality, selectivity, and polarity of a stationary phase or column.

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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.