Voltammetric behavior of selected genotoxic nitro compounds (2-nitrofluorene, 2,7-dinitrofluorene, 2-nitro-9-fluorenone and 2,7-dinitro-9-fluorenone) has been investigated using direct current voltammetry (DCV), differential pulse voltammetry (DPV) and adsorptive stripping differential pulse voltammetry (AdSDPV) at a mercury meniscus modified silver solid amalgam electrode (m-AgSAE). The optimum conditions have been found for their determination in a 1 : 1 mixture of methanol and aqueous Britton -Robinson buffer solution, with the limits of quantification, (LOQ), 2, 0.3, 0.5, and 0.5 mmol L À1 (DCV at m-AgSAE) and 0.2, 0.2, 0.4, and 0.2 mmol L À1 (DPV at m-AgSAE) for 2-nitrofluorene, 2,7-dinitrofluorene, 2-nitro-9-fluorenone, and 2,7-dinitro-9-fluorenone, respectively. An attempt at increasing the sensitivity using AdSDPV at m-AgSAE was successful only for 2-nitrofluorene (LOQ ¼ 2 nmol L À1 ). Practical applicability of the newly developed methods was verified on direct determination of the studied compounds in drinking and river waters with LOQs~10 À7 mol L À1 for all the studied compounds.

Elimination voltammetry with linear scan (EVLS) in connection with renewed mini-drop mercury electrodes provides valuable information about the character and kinetics of processes at electrode/electrolyte interfaces. Based on the experiment related to the hydrogen evolution, it is presented that the EVLS is more sensitive than other voltammetric methods. Using miniaturized mercury electrodes, the EVLS is capable of detecting the effect of spherical diffusion associated with both the scan rates and the size of an electrode drop.

We show that a liquid mercury drop electrode surface can be electrochemically renewed without mechanical detachment of the drop. Voltammetric experiments with a mechanically renewed stationary (hanging) mercury drop or meniscus electrode (SME) and an electrochemically renewed SME are compared. The measurements were performed with two surface active organic depolarizers, i.e., 2-aminoanthraquinone and dithiothreitol and surface inactive Cd(NO 3 ) 2 . The results show that efficient purely electrochemical renewal of the electrode surface of SME for voltammetric purposes is possible.