Voltammetric Determination of Selected Nitro Compounds at a Polished Silver Solid Amalgam Composite Electrode

Abstract

Voltammetric behavior of selected biologically active organic nitro compounds, namely 2-nitrofluorene, picric acid (2,4,6-trinitrophenol) and metronidazole, has been investigated using direct current voltammetry (DCV) and differential pulse voltammetry (DPV) at a polished silver solid amalgam composite electrode (p-AgSA-CE). The optimum conditions have been found for their determination in a 1 : 1 mixture of methanol and aqueous Britton-Robinson buffer of pH 5.0 for 2-nitrofluorene and in the aqueous Britton-Robinson buffer solutions of pH 2.0 and 4.0 for picric acid and metronidazole, respectively, with the limits of quantification (L Q s) 4, 0.1 and 2 mmol L À1 (DCV at p-AgSA-CE) and 3, 1 and 4 mmol L À1 (DPV at p-AgSA-CE) for 2-nitrofluorene, picric acid and metronidazole, respectively. An attempt to increase the sensitivity using adsorptive stripping voltammetry was not successful for all three test substances. For comparison, the UV-vis spectrophotometric determinations of studied compounds have also been carried out in methanol for 2-nitrofluorene (L Q % 1 mmol L À1) and in deionized water for picric acid). Practical applicability of the newly developed voltammetric methods was verified on direct determination of the studied compounds in drinking and river waters with L Q s around 10 À6 mol L À1 for all the studied compounds.

Effect of nano- and micro-alumina fillers on some properties of poly(methyl methacrylate) denture base composites

“…As reported by Topouzi et al, this phenomenon (i.e., decreasing fracture toughness) could be attributed to improper dispersion of the filler in the PMMA matrix, resulting in agglomeration and the formation of microcracks. 56 The improvement in fracture toughness could be attributed to incorporation of high-strength fillers 57 and silanization. 58 In addition, resistance to crack propagation increased as a result of toughening mechanisms, such as, crack deflection, 59-61 crack pinning/bowing, 59 matrix-filler interactions 59,62 and crack bridging.…”

Electroanalysis of Nitro and Amino Derivatives of Polycyclic Aromatic Hydrocarbons

“…Polarographic or voltammetric behavior, very similar to that described above, have been observed for some NPAHs at different types of electrode materials enabling the nitro reduction, e.g., at mercury electrodes [115,[119][120][121], silver amalgam based electrodes [122][123][124], carbon based electrodes [125] or boron-doped diamond film electrode (BDDFE) [126]. Dinitro-substituted NPAHs such as dinitronaphthalenes or dinitrofluorenes give usually rise to two, more or less split, four-electron waves/peaks in the protic media [113,121].…”

Silver Solid Amalgam Electrode as a Tool for Monitoring the Electrochemical Reduction of Hydroxocobalamin

“…These electrodes have been already utilized as an effective tool in voltammetric analysis of, e.g. heavy metals [24,[26][27][28], inorganic anions [27,29], organic nitrocompounds [30][31][32][33][34][35][36], carcinogens [33,[37][38][39], antineoplastic drugs [40][41][42], DNA [43][44][45], peptides [46], vitamins [32] or folate structure compounds [40,42,47,48].…”