Cathodic Electrochemical Determination of Herbicides in Acid Media Using a Bismuth Film Electrode

Abstract

A revised procedure for the preparation of bismuth film electrodes (BiFEs), adapted to improve its performance in acid media, is presented and applied for the analysis of herbicides under these conditions. Common carbon-based substrates have been studied for the preparation of ex situ BiFE as well as the influence of relevant parameters upon the bismuth film formation (plating solution, deposition potential and deposition time). A plating solution consisting of 0.60 mM Bi(NO 3 ) 3 in 0.10 M H 2 SO 4 and a careful selection of the plating potential (equal to the cathodic peak potential in this solution) applied during 360 s yields to a suitable BiFE in terms of stability and electroanalytical performance. The applicability of the BiFE was investigated for the analysis of the herbicides metamitron, metribuzin, maleic hydrazide and atrazine in nondeaerated solutions by square-wave voltammetry (SWV). In all cases the enhanced electrochemical performance of the BiFE over bare glassy carbon electrode (GCE) is evident. Herbicides signals at BiFE have improved sensitivity and a positive potential shift is observed when compared to bare GCE. The herbicide metribuzin (4-amino-6-tert-4,5-dihydro-3-methyl-thio-1,2,4-triazin-5-one) was determinated in nondeaerated solutions by square-wave voltammetry (SWV) using BiFE. Under optimal conditions, the dynamic linear range of concentrations is comprised between 10 and 200 mM and the detection limit is 6 mM.

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].…”

“…Further metal ions and species then are: Tl(I) in spiked model solutions [191], Sn(II) in canned fruit juices [188], Sb(V/III) in river and seawater [189], Co(II) in river water [175], Cr(VI) in dissolved polypropylene and sewerage [181], Ti(IV) in model solutions [173], V(V) in river water [179], and Te(IV) in natural water [187]. Finally, analytes of organic and biological origin are again of minor concern, represented by a series of herbicides (Metamitron, Metribuzin, Maleic Hydrazide, and Atrazine [165]), or pharmaceuticals from the family of aminosalycilate drugs (Sulfasalazine and Olsalazine [182]). …”

Determination of Atrazine in Natural Water Samples by Differential Pulse Adsorptive Stripping Voltammetry Using a Bismuth Film Electrode

“…However, few papers are described in the literature using BiFE to determine organic compounds such as drugs [15,16] and pesticides [17][18][19][20]. The application of a BiFE using a GCE substrate was recently carried out to determine the herbicide metribuzin by square-wave voltammetry [19]. Figueiredo-Filho et al [17] determined Paraquat in natural water samples using a bismuth film electrodeposited onto a copper electrode by differential pulse voltammetry (DPV).…”

Voltammetric Determination of Glucose at Bismuth‐Modified Mesoporous Platinum Microelectrodes

“…However, a survey of the literature indicates that the detection of metal ions is the major type of applications, whereas much less attention has been devoted to the use of bismuth-coated electrodes for the detection of organic compounds [14,15]. For the latter applications, the relatively high overpotential for hydrogen evolution that applies to the bismuth-coated electrodes has been exploited to widen the cathodic window, such that electroactive species, which reduce at rather high negative potentials, can be investigated even in very acidic media [14].…”