Determinations of organic acids in fruit juices are used by the beverage industry for flavor characterization, identification of spoilage, identification of adulteration by a less costly juice, and product labeling. In this study, inorganic anions and organic acids in diluted filtered apple and orange juice samples were determined on a Dionex IonSwift MAX-100 anion-exchange column using electrolytically generated hydroxide gradient from 0.1–65 mM KOH over 25 min at 15 μL/min.

A platform using Dionex ion chromatography (IC) coupled to triple quadrupole mass spectrometry (MS) was developed to measure various metabolites in Brassica napus seeds. The IC tandem mass spectrometry (IC-MS/MS) technique provides a good tool to identify and quantify metabolites in a complex matrix.

Here, the author describes an ion-exchange system that provides good separation of the polar metabolities with on-line desalting to allow MS detection. This technique will allow studies of key metabolites that do not separate well on traditional reversed-phase columns. Some ionic metabolites may be positional isomers adjacent to each other in a synthetic pathway and as such, are isobaric. In such cases, MS is not sufficient to differentiate the two compounds. There is clearly a need for adequate separation techniques for isomeric metabolites.

The characteristic aroma, acidity, and flavor of a coffee are attributed to the inorganic anions, organic acids, chlorogenic acid, and monosaccharides content. In this study, inorganic anions and organic acid anions in caffeinated and decaffeinated brewed coffee samples are separated within 20 min by anion-exchange chromatography on a capillary Dionex IonSwift MAX-100 (0.25 × 250 mm) column set using a gradient of potassium hydroxide eluent at 12 μL/min.

Fermentation broths are complex mixtures of nutrients, waste products, cells and cell debris, and desired products. Fermentation monitoring is important for many industries because carbon sources and metabolic by-products can impact the yield of the desired products. This application note describes the use of two different anion-exchange columns, IonPac AS11 and IonPac AS11-HC, with suppressed conductivity detection, to analyze common organic and inorganic anions in yeast and bacterial fermentation broths.