HIGHLY SENSITIVE DETECTION OF CATECHOLAMINE WITH INTERDIGITATED ARRAYMICROELECTRODES IN HPLC

The highly sensitive detection of catecholamine has been achieved by u sing an interdigitated array (IDA) microelectrode as an electrochemica l detector in a microbore high-performance liquid chromatography (HPLC ) system. The current responses for catecholamine are measured for IDA electrodes with different gaps between their adjacent band electrodes . An IDA electrode with a narrow pp produces a high current density an d reduces the influence of the auxiliary electrode position on the cur rent response. The current response measured for an IDA electrode inco rporated in the microbore HPLC system is about four times greater than that measured for a combination of the same IDA electrode and an ordi nary sized column due to current enhancement by redox cycling in the s lower stream.