Voltammetric Determination of Genotoxic 4-Nitroindane at a Mercury Meniscus Modified Silver Solid Amalgam Electrode

A silver solid amalgam electrode modified with mercury meniscus (m-AgSAE) was used as a non-toxic replacement of mercury electrodes in the voltammetric determination of genotoxic environmental pollutant 4-nitroindane (4-NI). The m-AgSAE was used to characterize of the overall electrode process during the 4-NI conversion using cyclic voltammetry (CV), and it was shown that the electrochemical reduction of 4-NI is an irreversible process controlled by both diffusion and adsorption. Techniques of direct current voltammetry (DCV) and differential pulse voltammetry (DPV) at the m-AgSAE were optimized for the development of a method for the sensitive determination of 4-NI. The application of the more convenient DPV method was proven on authentic drinking and river water samples. Limits of quantification (LQs) obtained under the following optimal conditions were 0.1 mu mol L-1 for DCV at the m-AgSAE (Britton-Robinson (BR) buffer pH 5.0-methanol (1 : 1); regeneration potentials E1,reg=-200 mV, E2,reg=-1100 mV) and 0.1 mu mol L-1 for DPV at the m-AgSAE (BR buffer pH 9.0-methanol (1 : 1); regeneration potentials E1,reg=-300 mV, E2,reg=-1300 mV). An attempt to decrease the LQ of the 4-NI determination by differential pulse adsorptive stripping voltammetry at the m-AgSAE was not successful. The LQs for DPV at the m-AgSAE in authentic samples of drinking and river water were 1.0 mu mol L-1 and 2.0 mu mol L-1 (BR buffer pH 9.0-drinking or river water (1 : 9); regeneration potentials E1,reg=-300 mV, E2,reg=-1300 mV), respectively. image