Voltammetry of a Novel Antimycobacterial Agent 1-Hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide in a Single Drop of a Solution
Abstract
The aim of this study is the development of a miniaturized voltammetric method for the determination of an antimycobacterial agent 1-hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide (HNN) in a single drop (20L) of a solution by cathodic and anodic voltammetry at a glassy carbon electrode. Cyclic voltammetry was used to investigate its redox properties followed by the optimization of differential pulse voltammetric determination in a regular 10mL volume.
The optimal medium for the analytical application of both cathodic and anodic voltammetry was found to be Britton-Robinson buffer pH7.0 and dimethyl sulfoxide (9:1, v/v). HNN gave one cathodic peak at around -0.6V and one anodic peak at around +0.2V vs.
Ag|AgCl (3molL(-1) KCl) reference electrode. Determination of HNN in a 10mL volume gave the limit of quantification around 10nmolL(-1) by both adsorptive stripping anodic and cathodic voltammetry.
Afterwards, miniaturized voltammetric methods in a single drop of solution (20L) were investigated. This approach requested some modifications of the cell design and voltammetric procedures.
A novel method of removing dissolved oxygen in a single drop had to be developed and tested. Developed miniaturized voltammetric methods gave parameters comparable to the determination of HNN in 10mL.
The applicability of the miniaturized method was verified by the determination of HNN in a drop of a bacterial growth medium.