Abstract A new microprocessor-based voltammetric and polarographic analyzer has been developed. Its outstanding features include the use of a high-level language for programming operation sequences and an algorithm giving the derivatives of the peaks obtained in the DPV, DPP, DNPV, DNPP and SWV modes; it has been shown that the amplitude measured between the two derived peaks is proportional to the amplitude of the original peak, and inversely proportional to the potential difference between the peak extremes of the derivative curves; this potential difference is in turn proportional to RT/nF , for a reversible reaction. This calculation method allows the automatic compensation of the residual slope, due either base line current or to an overlapping peak. This new analyzer has been tested successfully, for example, in the determination of UO 2+ 2 ions by adsorbed chathodic stripping voltammetry (ACSV). Some results obtained for in vivo analysis of dopamine traces in the DNPV mode on a carbon fiber microelectrode are also given; the microfiber electrode had previously undergone a particular electrochemical treatment which improved both sensitivity and selectivity notably.