Voltammetric Determination of Trace Amounts of 2‐Aminofluoren‐9‐one at a Mercury Meniscus Modified Silver Solid Amalgam Electrode

Abstract

Voltammetric behavior of the genotoxic environmental pollutant 2‐aminofluoren‐9‐one (2‐AFN) was 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). Optimum conditions were found for its DCV and DPV determination in a methanolBrittonRobinson buffer pH 4.0 (1 : 9, v/v) medium (in a concentration range from 0.1 to 100 µmol L−1 of 2‐AFN) and for its AdSDPV determination in a 0.2 mol L−1 acetate buffer pH 4.0 medium (from 0.01 to 0.1 µmol L−1 of 2‐AFN), with limits of quantification (LQs) of 0.2, 0.1 and 0.005 µmol L−1 for DCV, DPV and AdSDPV, respectively. For comparison, the UV spectrophotometric (measured at 274 nm) and fluorimetric (measured at 460 nm, using the excitation wavelength of 314 nm) determination of 2‐AFN were carried out in methanol, with LQs of 0.1 and 2 µmol L−1, respectively. Practical applicability of the newly developed voltammetric methods was verified on direct determination of 2‐AFN in model samples of drinking and river water, with the lowest LQs in the range of 5–10 nmol L−1.

Ultrasensitive electrochemical determination of metronidazole based on polydopamine/carboxylic multi-walled carbon nanotubes nanocomposites modified GCE

“…7 B), indicating two different reaction mechanisms of metronidazole. According to previous reports [39] , [48] , the reaction mechanisms of metronidazole are listed below: In pH values of 5·0–9·0: R−NO 2 + e − → R−NO 2 · − (slow step) R−NO 2 · − + 4H + + 3e − → R−NHOH + H 2 O (rapid step) In pH values of 9·0–11·0: R−NO 2 + e − → R−NO 2 · − (slow step) R−NO 2 · − + 3H 2 O + 3e − → R−NHOH + 4OH − (rapid step)

Fig. 7 (A) CVs of 500 µmol/dm 3 metronidazole in 0.1 M PBS (pH = 10) buffer solution at different pH values at the polydopamine/MWCNTs–COOH nanocomposites/GCE.

…”

Voltammetric determination of genotoxic 4‐nitroindane at a mercury meniscus modified silver solid amalgam electrode

“…Conventional types of electrodes, such as a dropping mercury electrode and a hanging mercury drop electrode, can be successfully substituted by electrodes containing small amounts of liquid mercury or non-toxic mercury amalgams [10,11] (e. g., polished [12][13][14], mercury meniscus modified [12,13,15,16], mercury film modified [12,17], bismuth film modified [18,19], or carbon film modified silver solid amalgam electrodes [20][21][22], silver solid amalgam paste electrodes with an organic pasting liquid [23,24], silver amalgam paste electrodes [25,26], polished silver solid amalgam composite electrodes [27,28], single crystal amalgam electrodes [29,30], or renewable silver amalgam film electrodes [31,32]). Novel silver amalgambased electrode materials combine unrivalled properties of mercury electrodes (broad cathodic potential window and relatively high sensitivity [33][34][35]) with requirements of Green Analytical Chemistry (GAC) (non-toxicity and environmental friendliness [36]).…”

“…A mercury meniscus modified silver solid amalgam electrode (m-AgSAE) was shown to be the most convenient alternative to mercury electrodes regarding the sensitivity of determination, limits of quantification, repeatability of measurements, and mechanical robustness for flow systems [23,33,34]. Most of the benefits of amalgam electrodes are discussed in reviews [9][10][11]37].…”