Supplementary material for the article: Stanković, D. M. Electroanalytical Approach for Quantification of Pesticide Maneb. Electroanalysis 2017, 29 (2), 352–357. https://doi.org/10.1002/elan.201600268

Supporting Information for: [https://doi.org/10.1002/elan.201600268]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2420

Supplementary material for the article: Stanković, D. M. Electroanalytical Approach for Quantification of Pesticide Maneb. Electroanalysis 2017, 29 (2), 352–357. https://doi.org/10.1002/elan.201600268

Supporting Information for: [https://doi.org/10.1002/elan.201600268]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2420

Fabrication of bismuth-oxychloride supported carbon paste electrode for sensitive Quinine sensing

Quinine is a natural white crystalline cinchona alkaloid that belongs to the aryl amino alcohol group of drugs, and it has antipyretic (fever reducing), antimalarial, analgesic, anti-inflammatory properties and a bitter taste. Today, quinine is considered as the best antimalarial drug since it is chiefly used in the treatment of falciparum malaria resistant to other antimalarials. Quinine is preferred where the disease has become highly resistant to other antimalarial drugs [1]. Quinine has a low therapeutic index, and it is potentially toxic and causes several side effects including nausea, blurred vision, diarrhea, abdominal pain, headache, fever, renal failure and asthma [2]. Since quinine is widely used as a bittering agent in tonic type drinks, a sensitive and discriminatory system for the discovery of quinine is essential for human health. In this work, a modified bismuth-oxychloride (BiOCl) carbon paste electrode was prepared for the detection of quinine. BiOCl nanoparticles were synthesized by the chemical coprecipitation method. The electrochemical properties of quinine at this electrode were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV), and differential pulse voltammetry (DPV). In addition, electrochemical impedance spectroscopy (EIS), inductively coupled plasma–optical emission spectrometry (ICP-OES), transmission and scanning electron microscopy (TEM and SEM) and X-ray diffraction (XRD) were used to characterize the synthesized materials. The prepared electrode showed better electrocatalytic response than the bare carbon paste electrode. After square wave voltammetry (SWV) optimization, the electrode showed a wide linear working range from 20 to 200 μM at pH 6 of Britton–Robinson buffer solution (BRBS) as the supporting electrolyte. The excellent selectivity of the proposed method, with good repeatability and reproducibility, strongly suggests a potential application of the method for the determination of quinine in pharmaceuticals. The practicality with good recoveries indicates that the morphology of the materials is closely related to other parameters, which in turn suggests that the developed approach can provide a cost effective, rapid, selective, and sensitive method for quinine monitoring

Preparation of NiO supported carbon paste electrode for sensitive and selective determination of Gallic acid in plant samples

In this work, nickel oxide (NiO) nanoparticles were synthesized by the chemical coprecipitation method and used for modification of the carbon paste electrode for GA detection and determination. Morphological properties of prepared material were investigated using ICP-OES (inductively coupled plasma–optical emission spectrometry), XRD (X-ray diffraction), SEM and TEM (Scanning and Transmission Electron Microscopy). The electrochemical properties of the prepared electrode and the behavior of GA over the modified electrode were examined using CV (Cyclic Voltammetry), EIS (Electrochemical impedance spectroscopy), and SWV (Square Wave Voltammetry)

Significant honey species Lamiaceae family

Medonosne biljne vrste porodice Lamiaceae pripadaju samoniklim biljkama, ali su mnoge i kulturne biljne vrste koje se uzgajaju. Na području Republike Hrvatske raste 230 vrsta i podvrsta te porodice. Lako se uzgajaju, a primjena im je vrlo široka. Cilj ovog rada je opisati građu cvijeta najbrojnije skupine biljaka, predstaviti najznačajnije medonosne biljke iz porodice Lamiaceae i odabranih vrsta: Lavandula angustifolia L., Salvia officinalis L., Rosmarinus officinalis L., Mentha sp. i Lamium sp.Honey species of Lamiaceae family belong to selfgrown plants, but many of them are also cultured plant species that are grown. In the territory of the republic of Croatia there are 230 species and subspecies of this family. They are easy to grow and their use is very wide. The goal of this final work is to describe the flower structure of the most numerous group of plants, to present the most significant honey plants from the Lamiaceae family and the selected species: Lavandula angustifolia L., Salvia officinalis L., Rosmarius officinalis L., Mentha sp. and Lamium sp

Significant honey species Lamiaceae family

Medonosne biljne vrste porodice Lamiaceae pripadaju samoniklim biljkama, ali su mnoge i kulturne biljne vrste koje se uzgajaju. Na području Republike Hrvatske raste 230 vrsta i podvrsta te porodice. Lako se uzgajaju, a primjena im je vrlo široka. Cilj ovog rada je opisati građu cvijeta najbrojnije skupine biljaka, predstaviti najznačajnije medonosne biljke iz porodice Lamiaceae i odabranih vrsta: Lavandula angustifolia L., Salvia officinalis L., Rosmarinus officinalis L., Mentha sp. i Lamium sp.Honey species of Lamiaceae family belong to selfgrown plants, but many of them are also cultured plant species that are grown. In the territory of the republic of Croatia there are 230 species and subspecies of this family. They are easy to grow and their use is very wide. The goal of this final work is to describe the flower structure of the most numerous group of plants, to present the most significant honey plants from the Lamiaceae family and the selected species: Lavandula angustifolia L., Salvia officinalis L., Rosmarius officinalis L., Mentha sp. and Lamium sp

Application of methyl-3,5-bis[(di(2-pikolil)amino)methyl]benzoate for modification of glassy carbon electrode

Cilj ove doktorske disertacije jeste razvoj novog tipa modifikovane elektrode na bazi staklastog ugljenika i njene optimizacije za odredjivanje sadržaja mikroelemenata u uzorcima iz životne sredine. Ova elektroda bi se bez prethodne pripreme koristila za određivanja sadržaja mikroelemenata u vodi, kao i u biološkim uzorcima i uzorcima zemljišta nakon mikrotalasne digestije.Razvoj ovakve elektrode unapredio bi današnje elektroanalitičke tehnike koje se zasnivaju na određivanju sadržaja mikroelemenata na visećoj kapi žive kao radnoj elektrodi, kao i na elektrodi od tankog živinog filma, iako ove imaju veoma nisku granicu detekcije i odličnu reproduktivnost. Zbog toksičnosti žive i njenih soli, elektrode od nje sve manje se koristi kao radne elektrode, a u nekim zemljama upotreba žive je potpuno zabranjena. Zbog toga se danas razvija veliki broj različitih tipova modifikovanih elektroda koje bi u budućnosti mogle da zamene živine electrode, a koje bi imale iste ili bolje karakteristike od ovih, što se pre svega odnosi na granicu detekcije, osetljivost i postizanje veće selektivnosti (zbog specifičnosti modifikovanih electroda). Najčešći primer modifikovanih elektroda predstavljaju elektrode modifikovane organskim jedinjenjima, koja mogu biti specifične i selektivne jonofore, ugrađene u polimernu matricu. Takve jonofore se mogu koristiti kao senzitivni elementi na radnim elektrodama prilikom elektroanalitičkih merenja. Na ovom principu razvijen je novi tip elektrode gde je kao polimerna matrica korišćen nafion a kao selektivna jonofora za modifikaciju kompleks metil-3,5-bis[(di(2- pikolil)amino)metil]benzoata sa bakrom (Cu-DPABA) na elektrodi od staklastog uglejnika (Cu-DPABA–NA/GCE). U cilju postizanja optimalnih rezultata, prvenstveno u pogledu granice detekcije i selektivnosti, ispitani su sledeći parametri: – debljina filma, – potencijal depozicije, – vreme depozicije i – pH opseg, elektrolit i stabilnost elektrode.The aim of this dissertation is the development of a new type of modified electrode based on glassy carbon, and its optimization for the determination of trace elements in environmental samples. This electrode would be used without prior preparation for the determination of trace elements in water, and in biological and soil samples prepared with microwave digestion. The development of such electrode would improve the present electroanalytical technique, which are based on the determination of trace elements on the hanging mercury drop as working electrode, and thin film of mercury electrode, although these electrodes have very low detection limit and excellent reproducibility. Because of the toxicity of mercury and its salts, mercury electrodes are less and less is use as working electrodes, and in some countries the use of mercury is completely forbidden. Now is a number of different types of modified electrodes in develop, that may eventually replace mercury electrode, and have the same or better performance, primarily related to the detection limit, sensitivity and greater selectivity (due to the specificificity of modified electrode). The most common example of modified electrodes are electrodes modified with organic compounds, which can be specific and selective ionophore, embedded in the polymer matrix. Such ionophores can be used as sensitive elements of the working electrodes in electroanalytical measurements. Based on this, a new type of electrode was developed. Nafion was used as polymer matrix, and as a selective ionophore for modification a complex methyl-3 ,5- bis [(di (2-pikolil) amino) methyl] benzoate with copper (Cu-DPABA) on a glassy carbon electrode was used (Cu-DPABA-NA/GCE). In order to achieve optimal results, especially in terms of detection limits and selectivity, following parameters were investigated: - Thickness of the film, - The potential of deposition, - Time of deposition, and - pH range, the electrolyte and electrode stability

Determination of Enalapril in Pharmaceuticals using Electrochemical Sensing with Amperometric Detection

In this work a new electrochemical method will be presented for the determination of enalapril in pharmaceutical tablets using unmodified screen printed electrode (SPE). The studies were done using amperommetric detection. Enalapril provides well defined, ovalshape oxidation peak at +1.05 V (vs. Ag/AgCl, 3.0 M KCl) in Britton-Robinson buffer solution (BRBS) at pH 5.0. After optimization of the experimental conditions, the influence of most common interferent compounds was tested. Under optimized experimental conditions, the signals were linearly proportional to the concentration of enalapril in the range from 2.5 to 90 mu M with a detection limit of 0.9 mu M. Repeatability of ten replicate measurements of 5 mu M enalapril was estimated to be 1.5%. Proposed method was successfully applied for the determination of the total amount of enalapril content in pharmaceutical preparations. Nevertheless, proposed method could be beneficial for the quick quantifications of enalapril in drugs using unmodified SPE electrode without any further treatment

Triangle-Shaped Cerium Tungstate Nanoparticles Used to Modify Carbon Paste Electrode for Sensitive Hydroquinone Detection in Water Samples

In this study, we propose an eco-friendly method for synthesizing cerium tungstate nanoparticles using hydrothermal techniques. We used scanning, transmission electron microscopy, and X-ray diffraction to analyze the morphology of the synthesized nanoparticles. The results showed that the synthesized nanoparticles were uniform and highly crystalline, with a particle size of about 50 nm. The electrocatalytic properties of the nanoparticles were then investigated using cyclic voltammetry and electrochemical impedance spectroscopy. We further used the synthesized nanoparticles to develop an electrochemical sensor based on a carbon paste electrode that can detect hydroquinone. By optimizing the differential pulse voltammetric method, a wide linearity range of 0.4 to 45 µM and a low detection limit of 0.06 µM were obtained. The developed sensor also expressed excellent repeatability (RSD up to 3.8%) and reproducibility (RSD below 5%). Interferences had an insignificant impact on the determination of analytes, making it possible to use this method for monitoring hydroquinone concentrations in tap water. This study introduces a new approach to the chemistry of materials and the environment and demonstrates that a careful selection of components can lead to new horizons in analytical chemistry

A novel carbon paste electrode modified by NP-Y2O3 doped with the g-C3N4 for sensitive electrochemical detection of herbicide bentazone in river, soil, and vegetable samples

Pesticides have a significant role in the world food chain in the setting of rising agricultural output demand and rising climate change impacts on agricultural productivity. Pesticide contamination across the world is not just a pressing issue; it also has the potential to get worse, for instance, because of movements in global production to nations with laxer environmental regulations [1]. In this work, we have designed a new electrochemical sensor for detecting bentazone (BZT) by using NP-Y2O3/g-C3N4 modified carbon paste electrode (CP). For the first time, the Pechini method was employed to synthesize the Y2O3 nanocomposite. The nanomaterial was characterized by Xray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In order to create an analytical technique for identifying and measuring BZT, the electrocatalytic characteristics of the suggested Y2O3/g-C3N4 modified CP electrode were examined. Using the CV and DPV approaches, the electrochemical behavior of BZT at the Y2O3/gC3N4 sensor was investigated. The proposed electrochemical sensor exhibited excellent electrochemical response toward BZT with a wide linear range of 1 to 100 µM, with a detection limit of 0.68 µM. The effect of possible interfering agents is negligible, confirming the good selectivity of the method. The sensor also displayed excellent sensitivity, reproducibility, and stability. Additionally, the Y2O3/g-C3N4 sensor was utilized for the detection of BZT in water and soil samples, and also in red and green pepper samples, and it exhibited good recovery results