NOVEL MERCURY-COATED CARBON-FIBER VOLTAMMETRIC DETECTOR FOR USE IN ADSORPTIVE STRIPPING FLOW-ANALYSIS

The preparation and application of a novel mercury-coated carbon fibre flow microelectrode are reported. The possibility to use this device in a flow system combined with alternating current (ac) stripping voltammetry is also demonstrated using mitoxantrone (MXT) as probe compound. The electrode is easy to prepare. Special analytical advantages have been observed when a.c. stripping voltammetry is applied to the adsorbed molecule on the electrode due to the reversibility of the electrochemical process. Once the operating system has been optimized a limit of detection for mitoxantrone of 4.5 x 10(-11) M was found. Manipulation of flow conditions allows the study of different concentration ranges. The direct analysis of serum samples without sample pretreatment, is also discussed and provided a linear calibration range between 4.5 X 10(-7) M and 4.5 x 10(-6) M.