Voltammetric determination of 2-amino-6-nitrobenzothiazole at two different silver amalgam electrodes

Abstract

Voltammetric behavior of genotoxic 2-amino-6-nitrobenzothiazole (ANBT) has been investigated using direct current voltammetry (DCV) and differential pulse voltammetry (DPV) at a polished silver solid amalgam electrode (p-AgSAE) and at a mercury meniscus modified silver solid amalgam electrode (m-AgSAE). The optimum conditions have been found for its determination in the concentration range of 0.2–100 μmol l −1 in a 9:1 (v/v) mixture of aqueous Britton–Robinson buffer solution (pH 10.0) and methanol, with the limits of quantification ( L Qs) 0.10 μmol l −1 (DCV at p-AgSAE), 0.19 μmol l −1 (DPV at p-AgSAE), 0.17 μmol l −1 (DCV at m-AgSAE) and 0.12 μmol l −1 (DPV at m-AgSAE). An attempt at increasing the sensitivity using adsorptive stripping DCV or DPV at both p-AgSAE and m-AgSAE was not successful. Practical applicability of the newly developed methods was verified on direct determination of ANBT in spiked samples of drinking and river water, with L Qs ∼ 10 −7 mol l −1.