ELECTROCHEMICAL PRETREATMENT OF CARBON-FIBER MICROELECTRODES FOR THE DETERMINATION OF FOLIC-ACID

An electrochemical pretreatment regime was optimised for the determination of folic acid at cylindrical carbon fibre microelectrodes. The effects of pretreatment on the functional characteristics of the microelectrode were examined. The pretreated electrode gave rise to higher faradaic and capacitive currents, presumably due to the presence of new surface functionalities. Differential pulse voltammograms of folic acid recorded in 0.1 M perchloric acid at the activated electrode exhibited a very well defined reduction peak resulting in a detection limit of 1 x 10(-8) M with a linear range of 2 x 10(-8) M to 1 x 10(-6) M folic acid.