Recent advances in pulsed amperometric chromatographic detection with Ppatinum electrodes

ANYL 21

Jun Cheng and Petr Jandik. R & D, Dionex Corporation, 445 Lakeside Drive, Sunnyvale, CA 94085
Pulsed amperometric detection (PAD) is widely accepted as a detection method for liquid chromatography, capillary electrophoresis and flow-injection analysis. Traditionally, PAD with platinum electrodes has been limited to compounds containing hydroxyl, amine, aldehyde, methoxy and S-containing functional groups.

During our development of microfabricated platinum electrodes, we experimented with modified waveforms with the objective to limit the etch rate of the thin platinum layer deposited on a polymeric substrate. We have achieved that goal and demonstrated a reproducible detection performance of disposable thin film platinum electrodes lasting up to two weeks. When applying the newly developed waveform, we discovered that a possibility of direct pulsed amperometric detection could be extended to new classes of analytes such as ketones, ethers, carboxylic acids sulfoxides, alkenes, and alkynes.

Our report describes the development of the new waveform and presents illustrative examples of the new detection methodology.