Amperometric detection of catecholamines with liquid chromatography at a polypyrrole-phosphomolybdic anion-modified electrode

✍ Scribed by Anhua Liu; Erkang Wang

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 775 KB
• Volume: 296
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)80261-0

✦ Synopsis

A conducting polypyrrole film immobilized with PMo,aO&-anion on a glassy carbon electrode was prepared by an electrochemical method. This kind of chemically modified electrode (CME) was prepared successfully by doping the polypyrrole film electrode with heteropolyacid under a cycling potential between -0.2 and + 0.6 V in 0.5 mol 1-l H,SO, containing Na,PMO,,O,O dopant. The experimental results show that an electrode modified with a heterophosphomolybdic acid-polypyrrole film has a catalytic effect on the oxidation-reduction of catecholamines. When employed with a dual-electrode arrangement in liquid chromatography with electrochemical detection using the PPy-PMo,,O&-electrodes as generating and collecting detectors, high effective collection efficiencies for catecholamines were achieved with a linear response range over three orders of magnitude and a detection limit of 5.0 x lo-' mol I-' for norepinephrine.

The amperometric response showed very good sensitivity and stability for catecholamine detection.