O. Niwa et al., IMPROVED DETECTION LIMIT FOR CATECHOLAMINES USING LIQUID-CHROMATOGRAPHY ELECTROCHEMISTRY WITH A CARBON INTERDIGITATED ARRAY MICROELECTRODE, Journal of chromatography B. Biomedical applications, 670(1), 1995, pp. 21-28
Citations number
21
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Journal title
Journal of chromatography B. Biomedical applications
The detection limit of catecholamines can be lowered by using a carbon
-based interdigitated array (IDA) microelectrode as a detector for liq
uid chromatography (LC). The IDA electrode is more sensitive than conv
entional glassy carbon electrodes due to the high current density caus
ed by radial diffusion at each microband, and redox cycling between tw
o microband arrays. Since the number of redox cycles increases at lowe
r flow-rates, the carbon IDA is particularly useful for microbore LC.
In an LC system with a l-mm microbore column and a carbon IDA electrod
e, the peak height of dopamine (DA) and DOPAC did not decrease with de
creasing flow-rate because of this redox cycling. A low detection limi
t of 5 fg (32 amol) and 9.6 fg (57 amol) was obtained for DA and DOPAC
due to the high current density and low background noise level (0.1 p
A) at the carbon IDA electrode. The total charge generated by oxidizin
g DA at the anodic array was more than the value calculated by assumin
g that all the DA molecules were oxidized.