Enhanced electroanalytical performance for diclofenac detection through optimizing voltammetric operating conditions

In this study, the influence of the operating conditions of the voltammetric techniques, i.e., differential-pulsed voltammetry (DPV) and square-wave voltammetry (SWV) on the electroanalytical performance of fullerene-carbon nanofiber paste electrode (Full-CNF) for diclofenac (DCF) determination is studied. The optimization of the step potential (SP) and the modulation amplitude (MA) were achieved for DPV, which were further applied for SWV technique. The influence of frequency was tested and the SP of 25 mV, an MA of 200 mV, at the scan rate of 0.1 V·s-1 and frequency of 5 Hz were found as optimized voltammetric operating conditions related to the sensitivity for the determination of DCF in aqueous solution

Simultaneous/selective voltammetric detection of diclofenac and tetracycline in water on graphene modified-boron-doped diamond electrode

The graphene oxide modified boron-doped diamond electrode (GO/BDD) was obtained electrochemically and tested by cyclic voltammetry (CV) to detect diclofenac (DCF) from antiinflammatory pharmaceuticals class and tetracycline (TC) from antibiotics one, which belongs to emerging pollutants from water. Graphene reduced electrochemically from its oxide showed enhanced sensitivity in determining individual and selective or simultaneous of DCF and TC. The cyclic voltammetry method - based protocol for selective/simultaneous detection of DCF and TC was developed in this study using a commercial boron-doped diamond (BDD) electrode modified with graphene oxide (GO)

Voltammetric detection of tetracycline in water at boron-doped diamond electrode

In this work a voltammetric based protocol for detection of tetracycline (TC), considered as emergent pollutant in water, was developed. The electrochemical behavior of TC studied by cyclic voltammetry was considered to optimize operating conditions of advanced voltammetric tehniques, e.g., differential-pulsed voltammetry (DPV) and square-wave voltammetry (SWV). The best electroanalytical parameters for TC detection of 2,29 µA/µM sensitivity and limit of detection (LOD) were achieved using SWV under SP of 0.05V, MA of 0.1V and frequency of 10 Hz

The role of temperature in the bioaccumulation processes of mangan from surface water, in species Salvinia natans (L.) All.

In this article we wanted to demonstrate the influence that temperature has on the processes of manganese accumulation in the species Salvinia natans (L.) All. In order to reach the proposed objective, different concentrations of manganese present in the water were tested at different temperature levels (15°, 25° and 35° C) and the samples of plant material were analyzed at different time intervals (0h, 24h, 72h and 120h)

Electrochemical denitrification of water for drinking purpose

Electrocoagulation was used as method of groundwater denitrification for the purpose of obtaining drinking water. The experiments were carried out by using both synthetic solutions and groundwater from the West of Romania. The sacrificial anode was made of aluminium and the cell was equipped either with stainless steel or aluminium cathodes. Also, Linear Scan Voltammetry (LSV) experiments were carried out in order to know the behaviour of aluminium sacrificial anode during the anodic process

Development of groundwater management by using electrocoagulation for removal of fluoride and coexisting anions

The electrocoagulation was applied to removal of fluoride and coexisting anions from simulated groundwater. The concentration of fluoride, chloride and sulfate was of 5 ppm, 347 ppm and 199 ppm, respectively. The influence of pH, current density, electrolysis time and sulfate presence were studied. Fluoride and sulfate removal efficiency, chloride concentration and specific energy consumption were calculated

Diatoms and their role in aquatic ecosystems

The present article aimed to determine diversity and abundance of diatoms in the river basin of the Cerna River. In order to achieve the objective, samples were taken from the entire course of the river, from 9 specific points (I, II, III, IV, V, VI, VII, VIII, IX) in spring-summer of 2020. 53 species of diatoms classified in 21 genera were determined

Influence of phosphorus and nitrates on the species development of Lemna minor L.

In this paper we wanted to determine the influence of phosphorus and nitrates in the development of Lemna minor L. To achieve this purpose, eight different growth variants were proposed, starting from the Hoagland culture medium, where the concentration of these two compounds varied. The growth rate in the eight experimental variants, ranges between 150% - 325%, with a minimum in the control sample and a maximum at the highest concentration of phosphorus in water

Graphene Oxide Electroreduced onto Boron-Doped Diamond and Electrodecorated with Silver (Ag/GO/BDD) Electrode for Tetracycline Detection in Aqueous Solution

A new electrochemical sensor designed by modifying the commercial boron-doped diamond (BDD) electrode with graphene oxide (GO) reduced electrochemically and further electrodecorated with silver (Ag), named the Ag/GO/BDD electrode, was selected among a series of the BDD, GOelectroreduced onto BDD (GO/BDD) and silver electrodeposited onto BDD (Ag/BDD) electrodes for the detection of tetracycline (TC) in aqueous solution. The best results regarding the sensitivity of 46.6 µA·µM−1·cm−2 and the lowest limit of detection of 5 nM was achieved using square-wave voltammetry (SWV) operated at the step potential of 5 mV, modulation amplitude of 200 mV and the frequency of 10 Hz in alkaline medium. The application of the alkaline supporting electrolyte-based procedure is limited for water monitoring due to the presence of chloride that interferes with TC detection; however, it can be applied for quantitative determination of pharmaceutical formulations. 0.1 M Na2SO4 supporting electrolyte eliminated chloride interference and can be used for the application of Ag/GO/BDD in practical detection of TC in water

Graphene Quantum Dots and Cu(I) Liquid Crystal for Advanced Electrochemical Detection of Doxorubicine in Aqueous Solutions

Two paste electrodes based on graphene quantum dots and carbon nanotubes (GRQD/CNT) and one modified with a homoleptic liquid crystalline Cu(I) based coordination complex (Cu/GRQD/CNT) were obtained and morphostructurally and electrochemically characterized in comparison with simple CNT electrode (CNT) for doxorubicine (DOX) detection in aqueous solutions. GRQD/CNT showed the best electroanalytical performance by differential pulse voltammetry technique (DPV). Moreover, applying a preconcentration step prior to detection stage, the lowest limit of detection (1 ng/L) and the highest sensitivity (216,105 µA/mg·L−1) in comparison with reported literature data were obtained. Cu/GRQD/CNT showed good results using multiple pulse amperometry technique (MPA) and a favorable shifting of the potential detection to mitigate potential interferences. Both GRQD-based paste electrodes have a great potential for practical utility in DOX determination in water at trace concentration levels, using GRQD/CNT with DPV and in pharmaceuticals formulations using Cu/GRQD/CNT with MPA