In the present work, we aimed on optimizing liquid chromatography coupled with twelve channel coulometric detector to detect markers of oxidative damaging of nucleic acids. Primarily, we aimed on investigating of influence of fundamental experimental conditions such as composition of mobile phase and its flow rate, column temperature and working electrodes potential on current responses of 8-hydroxyguanosine. The optimized conditions were as follows -- mobile phase: acetate buffer with flow rate of 0.5 ml.min-1, working electrodes potential: -400 mV, column temperature: 30 degree of C. The detection limit (3 S/N) was evaluated as tens of femtomoles per injection. Based on the results obtained the technique could be used for analysis of clinical samples.