ABSTRACT Capillary high-performance anion-exchange with pulsed amperometric detection (HPAE-PAD) is a technique that uses capillary columns (e.g., 0.4 mm i.d. columns) packed with ion-exchange resin and a newly designed capillary amperometric cell with a gold working electrode and a palladium hydrogen (PdH) reference electrode. The cell body is made of titanium and serves as a counter electrode. An electrolytic eluent generator optimized for operation at capillary flow rates is also included in the system. To characterize the new technique, the authors generated analytical performance data under a number of different conditions based on eluent composition and flow rate. Separation efficiency and concentration detection limits were comparable with those achieved using analytical-scale chromatography. However, the mass detection limits were significantly improved, and the range of linearity of calibration plots was broader than what is typically achieved using analytical- scale chromatography. Next, the authors used capillary HPAE-PAD for the analysis of carbohydrates in cell cultures, fermentation broths, protein hydrolyzates, beverages, and food samples. Because of its low flow rates (5–10 μL/min), capillary HPAE-PAD offers the convenience of extremely low eluent usage (1 L of water lasts approximately 2 months). An additional advantage is that the system requires only very small injection volumes (0.4 μL). Analytical Performance of Capillary High-Performance Anion-Exchange with Pulsed Amperometric Detection Jun Cheng, Petr Jandik, Yan Liu, Victor Barreto, and Christopher Pohl, Dionex Corporation, Sunnyvale, CA, USA EXPERIMENTAL Instrument: Dionex ICS-5000 Ion Chromatography System, including: • Autosampler with low-volume injector valve (0.40 µL) • Dual pump (DP) with flow range from 1 to 100 µL/min • Capillary Eluent Generator (Cap EG) • Continuously Regenerated–Capillary Anion Trap Column (CR-ATC) • IC Cube™ cartridge with capillary CarboPac ® PA 20 column (0.40 × 150 mm) • Capillary ED cell (130 nL dead volume) equipped with palladium hydrogen reference electrode and disposable gold working electrode (1 mm diamter) System Control and Data Processing: Dionex Chromeleon ® 6.8 Chromatography Data System Software Chromatographic Conditions: see figures for detail. Figure 1. Block diagram of a Capillary Reagent-Free ™ HPAE-PAD system with electrochemical detection. 28345 Sample Injector (Autosampler) Separation Column Waste Amperometric Detector Data Management Cell Effluent H 2 0 High-Pressure Nonmetallic Pump Electrolyic Eluent Generator (OH - ) CR-TC Degasser