Anion-exchange chromatography is a liquid-chromatographic separation in which negatively charged analytes compete for positively charged sites on a stationary phase and are eluted by a competing anion in the mobile phase ^[1][2]. In the chromatography of natural products and related ionic species the concept is bounded by that electrostatic retention mechanism: the stationary phase is an anion exchanger (typically a quaternary ammonium or related cationic group), and the solutes that are retained are anions. Essential features are a charged surface whose ion-exchange capacity sets the load, a buffered eluent whose pH controls the charge state of weakly acidic analytes, and a salt or pH gradient that displaces bound anions in order of their effective affinity ^[2][3]. High-performance anion-exchange chromatography of carbohydrates, often paired with pulsed amperometric detection, exploits the weak acidity of sugar hydroxyl groups at high pH to retain otherwise neutral monosaccharides and polysaccharides as oxyanions ^[2][3][4]. The technique is distinguished from cation-exchange chromatography by the sign of the exchanged ion, from reversed-phase chromatography by the electrostatic rather than hydrophobic retention mechanism, and from ion-exclusion chromatography by the direction of the electrostatic interaction. Conceptual limits exclude electrophoretic separations that do not employ a packed or immobilized ion-exchange bed.