Anodic oxidation of parabens in acetic acid–acetonitrile solutions

Abstract

The electrochemical properties of esters of p-hydroxybenzoic acid, called parabens, were investigated on a carbon fiber microelectrode and on a glassy carbon macroelectrode in glacial acetic acid containing 20 % acetonitrile (v/v) and sodium acetate as a supporting electrolyte. The anodic oxidation of parabens in this medium proceeds in a single stage giving well-shaped peaks or waves in the same potential region of above 1.0 V (vs. Ag/AgCl). The electrode process was characterized as being quasireversible, diffusion-controlled, and proceeds with the exchange of one electron and one proton. Phenoxyl radicals as products of the electrode process are chemically unstable and participate in the successive irreversible homogenous reactions resulting in electroinactive products (E q C i mechanism). Smaller oxidation potentials for parabens in comparison to such unsaturated fatty acids as oleic, linoleic, and linolenic ones indicate that these compounds can show antioxidative properties. Since parabens are often used as preservatives in many products, the results presented can be found useful in the determination of their total content in real samples.

Review on Life Cycle of Parabens: Synthesis, Degradation, Characterization and Safety Analysis

“…Most of parabens, existing in surface water, household water and the waste water, can be decomposed during water treatments in reservoirs [19]. 5). Some water containing parabens are irrigated, which means that the soils retain some parabens [20].…”

“…Nature is smart and discovered these functions of parabens thousands of years ago. Parabens occur naturally in carrots, blueberries, olives, strawberries and mangoes, containing similar preservation properties as synthetic parabens; helping them to defend themselves against various micro-organisms [5][6][7]. Human started to discover these functions of parabens about 100 years ago, which means that parabens are among the most welldocumented ingredients [8] in the market.…”

Voltammetric analysis of nitroxoline in tablets and human serum using modified carbon paste electrodes incorporating mesoporous carbon or multiwalled carbon nanotubes

“…6). 29,47 Quantification studies Voltammograms of 5.0 Â 10 À6 M bulk nitroxoline were recorded in different supporting electrolytes {B-R universal buffers (pH 2.0-8.0), acetate buffers (pH 3.5-5.6), phthalate buffer (pH 4.0) and in 0.01 M HCl} using LS-AdSV and SW-AdSV methods. This phenomenon suggests that preconcentration by adsorptive accumulation of the drug at developed CP electrodes can improve the surface concentration of nitroxoline and nally enhance its oxidation signal.…”

“…So, the oxidation peak (O 1 ) may be attributed to oxidation of phenolic hydroxyl group of nitroxiline 29,30 while the reduction peaks (R 1 & R 2 ) may be attributed to reduction of its nitro group. 30,31 The absence of another irreversible oxidation peak at more positive potential than peak O 1 in the 1st forward scan or a redox couple at less positive in the subsequence scans indicate that the reduction of OH group takes place via one proton and one electron to form stable phenoxyl radical 29,[32][33][34] that did not further oxidize 35 or react with water [32][33][34] to form quinone derivatives that is reversibly reduced, in another pathway. However, the reduction peaks R 1 and R 2 may be attributed to reduction of nitro group to the hydroxyl amine stage and then to amine stage via consumption of 4 and 2 electrons, respectively, 36,37 not to the hydroxyl amine only.…”

A Boron‐Doped Diamond Anode for the Electrochemical Removal of Parabens in Low‐Conductive Solution: From a Conventional Flow Cell to a Solid Polymer Electrolyte System

“…Previous studies have proven that parabens can be successfully removed from aqueous solutions through different advanced oxidation processes (AOPs) including Fenton processes, ozonation, catalytic and/or photocatalytic ozonation, sonolytic degradation, photosonolysis, photodegradation, photocatalytic degradation, and electrochemical oxidation …”