HIGHLY SENSITIVE DETECTION OF CATECHOLAMINE WITH INTERDIGITATED ARRAY MICROELECTRODES IN HPLC

The highly sensitive detection of catecholamine has been achieved by using an interdigitated array (IDA) microelectrode as an electrochemical 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 and reduces the influence of the auxiliary electrode position on the current response. The current response measured for an IDA electrode incorporated in the microbore HPLC system is about four times greater than that measured for a combination of the same IDA electrode and an ordinary sized column due to current enhancement by redox cycling in the slower stream.