Chris Pohl

The disinfectants commonly used to treat public drinking water can react with naturally occurring organic and inorganic matter in the source water to form disinfection byproducts such as haloacetic acids. Here, we describe the use of two-dimensional matrix-elimination ion chromatography (MEIC) for haloacetic acid analysis. This method minimizes the impact of matrix ions.

Accounting for the inherent heterogeneity of monoclonal antibodies is essential to ensure production of consistent and safe therapeutics and, in light of this, there is an array of chromatographic and supporting regulatory systems. Robust characterization and analysis of monoclonal antibodies is becoming a fast and straightforward process thanks to the myriad technological advances underpinning this rapidly evolving area.

This article describes the analysis of fluorescently labelled N-glycans released from proteins by liquid chromatography–mass spectrometry (LC–MS).

A summary of the latest in new ion-exchange phases for ion chromatography, with a focus on general aspects of phase design and then a review of anion-exchange and cation-exchange columns introduced in the past few years

The new 1 mm i.d. ProSwift strong cation-exchange (SCX) column is a polymethacrylate-based monolithic column with sulfonate functionality.

Dionex Application Note

In this article, Chris Pohl summarizes some of the stationary phases that have been developed for modern ion-exchange and ion chromatography.

Carbonyl compounds, including low molecular weight aldehydes and ketones, have environmental and health concerns; for example, short-term exposure to aldehydes can irritate the eyes, skin, and upper respiratory tract. Motor vehicles emit reactive hydrocarbons that undergo photochemical oxidation in the atmosphere, which generates formaldehyde and other carbonyls. In addition, formaldehyde contributes to the formation of photochemical ozone. California Air Resources Board (CARB) Method 1004 (1) provides an analytical method for the automotive industry to monitor 13 carbonyl compounds in engine exhaust. US EPA Method TO-11A (2) and Method 8315 (3) monitor atmospheric formaldehyde and 14 other carbonyl compounds and are used for a variety of environmental and occupational health purposes. In these methods, carbonyl compounds are trapped as the dinitrophenylhydrazine (DNPH) derivatives before analysis by HPLC.

The new reversed-phase ProSwift® 1 mm i.d. column is a divinylbenzene-based monolithic column for routine chromatography of proteins and other biomolecules. It is available in two different lengths. The shorter (1 Ã- 50 mm) format is designed for fast separations and the longer (1 Ã- 250 mm) format is intended for high resolution analytical separations. However, depending on the application, either can be used for separation of proteins and for coupling with mass spectrometry.

Ion exchange is one of the older of the chromatographic techniques yet each year new products continue to hit the market. In this paper, Chris Pohl of Dionex will summarize some of the stationary phases that have been developed for modern ion-exchange and ion chromatography. He will focus on phase design and then turn his attention to new anion and cation columns introduced in the last couple of years.