Monitoring of Photocatalytic Degradation of Selected Neonicotinoid Insecticides by Cathodic Voltammetry with a Bismuth Film Electrode

Abstract

An electroanalytical method has been developed for the determination of two water soluble pyridine based neonicotinoid insecticides (imidacloprid and acetamiprid) by differential pulse voltammetry with a bismuth film electrode in aqueous Britton -Robinson buffer solution as supporting electrolyte. The bismuth film electrode preparation was optimized for cathodic voltammetric application. The reduction peaks of the neonicotionids appeared at potentials more negative than À 0.5 V (BiFE vs. Ag/AgCl/3.0 M KCl) and the signal characteristics depended on the pH of the supporting electrolyte. The best analysis conditions were found to be pH 8.0 for imidacloprid and pH 3.0 for acetamiprid at the following measurement parameters: pulse amplitude 50 mV, pulse width 50 ms and scan rate 25 mV. Calibration curves were linear in the concentration range of 2.43 -51.1 mg/cm 3 for imidacloprid and 2.95 -47.3 mg/cm 3 for acetamiprid, while the detection limits were 0.73 mg/cm 3 and 0.88 mg/cm 3 for imidacloprid and acetamiprid, respectively. The electroanalytical method has allowed monitoring the heterogeneous photocatalytic (O 2 /TiO 2 /UV) degradation of the two insecticides via their disappearance. The dynamics and the reaction rate determined on the basis of the electrochemical data were validated with HPLC/DAD and FTIR measurements.

A Decade with Bismuth‐Based Electrodes in Electroanalysis

“…Even though the vast majority of practically orientated research into bismuth electrodes has focused on the determination of inorganic ions, there has also been increasing effort towards the determination of organic compounds. The analysis of organic compounds represents approximately 15% of the total research activity into BiEs and can be split into four main areas, namely (i) fundamental investigations into the analysis of model organic compounds including nitrophenols [17,32]; (ii) determination of pharmaceutical substances including aminosalicylate drugs [182], Daunomycin [48], Tetracycline [97] and Diclofenac [117]; (iii) the determination of pesticides [80,123,127,144,165]; and (iv) the determination of various compounds of biological relevance [19,84,107,111].…”

“…Of permanent interest was the reliable configuration of the bismuth film-plated glassy carbon electrode ("BiF-GCE"; e.g. [127,133,138,142,144,160,162]), other reports offered the newly proposed combinations ("BiFPtE" [163] and "BiF-CuE" [132]), or even the alreadydescribed arrangements such as "BiBE" [130] (with its mixed variant, "Bi/Au-BE" [131]), bismuth film-plated and bismuth powder-modified carbon paste electrodes ("BiFCPEs" and "Bi-CPEs" [147,164], including a new zeolitedoped configuration [143]), Bi-nanopowder-containing boron-doped diamond or thick-film graphite electrode, Bi(n)-BDDE [130] and Bi(n)-TFGE [149], respectively, plus some innovative miniaturized constructions [148,161]. Together with routine electroanalytical testing and application, in focus were the bismuth microlayers [128 -130, 132, 148, 151], when using UV-vis reflectant spectroelectrochemistry (SPEC [138]), or electrochemical impedance spectroscopy (EIS [144]).…”

“…However, organic substances were predominantly represented by environmental pollutants such as pesticides from the neonicotinoid family (Imidacloprid and Acetamiprid [127]), or nitroaromate derivatives (Methylparathion [144], known also as organophosphate, and 4-amino-3-nitrophenol [164]). Finally, a couple of papers contributed to biological/clinical analysis, which was the case of the determination of cysteine [147] or glucose sensing in selected wine samples [150].…”

Removal of 1,4-dioxane from industrial wastewaters: Routes of decomposition under different operational conditions to determine the ozone oxidation capacity

“…Fourier transform infrared (FTIR) spectroscopy is an alternative method to analyze different molecule groups and structures [33,34]. Recently, Merayo et al [35] demonstrated the advantages of on-line FTIR spectroscopy to monitor the evolution of reaction intermediates during the Fenton oxidation of aqueous 1,4-dioxane, showing that a good calibration could provide valuable information in situ, avoiding expensive and time-consuming sample preparation and analyses.…”

Sensitive Electrochemical Determination of Folic Acid Using ex–situ Prepared Bismuth Film Electrodes

“…By using of an "environmentally friendly" electrode material -bismuth (mostly as electrodeposited bismuth film as it is well known resemblance in electrochemical behavior between Bi and Hg) in electrochemical "stripping" analysis, [20,21,22] it is possible to overcome issues related to mercury based materials. Although conventional and micro bismuth film electrodes have been widely used in electrochemical analysis of various organic compounds [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] their relevance for folic acid determination has been very poorly exploited. Only Ananthi et al [38] reported determination of folic acid using glassy carbon electrode modified with an electrodeposited bismuth nanowires by square wave voltammetry.…”