Papers by Magdalena Jakubczyk
Elektroanaliza metyloizotiazolinonu w wodnych farbach ściennych
Przemysł Chemiczny, Jan 28, 2024
Woltamperometryczne oznaczanie tymolu w preparatach farmaceutycznych
PRZEMYSŁ CHEMICZNY
International Journal of Electrochemical Science
The unknown electrochemical properties of phenoxyethanol (PE)-the most commonly used preservative... more The unknown electrochemical properties of phenoxyethanol (PE)-the most commonly used preservative in cosmetics were studied. The measurements were performed on platinum micro-and macroelectrodes by linear sweep (LSV), cyclic (CV) and differential pulse voltammetry (DPV) in mixed solvent acetic acid-acetonitrile (20%, v/v) containing NaClO4 as a supporting electrolyte. The anodic oxidation process has proved to be quasireversible, diffusion-controlled and proceeding with exchange of one electron giving the unstable cation radical as a primary product (EqCi mechanism). Very good reproducibility of the DPV curves and the wide linearity range up to 1 mmol L-1 indicate that the proposed medium can be successfully applied to develop the first voltammetric method of this preservative determination in pharmaceutical and cosmetic products.
Molecules
Thymol and carvacrol—the components of herbal spices—are known for their broad biological activit... more Thymol and carvacrol—the components of herbal spices—are known for their broad biological activity as antimicrobials and antioxidants. For this reason, it is important to develop new methods for their determination in plant material. A simple, rapid, and sensitive method for determination of total content of these analytes in herbal spices using differential pulse voltammetry (DPV) has been developed. The basis of the research is the oxidation process of isopropylmethylphenols on a platinum microelectrode in glacial acetic acid containing acetonitrile (20%, v/v) and 0.1 mol L−1 sodium perchlorate as the supporting electrolyte. Linear voltammetric responses for thymol and carvacrol were obtained in a wide concentration range from 0.39–1105 and 0.47–640 µg mL−1, with a low detection limit of 0.04 and 0.05 µg mL−1, respectively. The analysis was performed using the multiple standard addition method. The results of the voltammetric determination are in good agreement with the data of th...
Materials
Electrochemical sensors in electroanalysis are a particularly useful and relatively simple way to... more Electrochemical sensors in electroanalysis are a particularly useful and relatively simple way to identify electroactive substances. Among the materials used to design sensors, there is a growing interest in different types of carbon. This is mainly due to its non-toxic properties, low cost, good electrical conductivity, wide potential range, and the possibility of using it in both aqueous and nonaqueous media. The electrodes made of carbon, and especially of carbon modified with different materials, are currently most often used in the voltammetric analysis of various compounds, including preservatives. The objective of this paper is to present the characteristics and suitability of different carbon materials for the construction of working electrodes used in the voltammetric analysis. Various carbon materials were considered and briefly discussed. Their analytical application was presented on the example of the preservatives commonly used in food, cosmetic, and pharmaceutical prep...
Badania i rozwój młodych naukowców w Polsce : nauki przyrodnicze cz.1
Rapid, simple, and safe for the environment voltammetric method for direct determination of total... more Rapid, simple, and safe for the environment voltammetric method for direct determination of total content of esters of p-hydroxybenzoic acid (PHB), named as parabens, in pharmaceutical preparations has been developed. Performed determinations were based on differential pulse voltammetry (DPV) at a carbon fiber disk microelectrode (CF) in glacial acetic acid containing 20% acetonitrile (v/v) and 0.1 mol L -1 sodium acetate as a supporting electrolyte. Linear calibration plots for PHB, methylparaben and propylparaben were obtained over the corresponding concentration range of 0.75 47.05, 0.89 40.73 and 1.20 36.62 mg L -1 with limit of detection of 0.07, 0.08 and 0.10 mg L -1 , respectively. This developed procedure allows the determination of parabens without the need for their separation from the matrices, and thereby aids in achieving desired accuracy, precision, and reproducibility of the results. This method has been successfully applied to their determination in commercially avai...
Open Chemistry
A simple, highly sensitive, and selective differential pulse voltammetry method for the determina... more A simple, highly sensitive, and selective differential pulse voltammetry method for the determination of α-lipoic acid (LA) in pharmaceutical preparations was developed and validated. The method is based on a quasi-reversible, diffusion-controlled, one-electron anodic oxidation of LA on a boron-doped diamond electrode (BDDE) in a McIlvaine (citrate-phosphate, C-PB) buffer solution at pH 3.0. For the first time, this environment was used for LA determination. A linear calibration curve was obtained within the concentration range 5.82 × 10−8 to 4.00 × 10−4 mol L−1 with a correlation coefficient of 0.9999. The limits of detection was estimated to be 1.94 × 10−8 mol L−1, which is one of the lowest values characteristic of voltammetric and chromatographic methods of LA determination. The proposed procedure is sensitive, accurate, and precise. Its utility was demonstrated in the determination of LA in pharmaceuticals without the need for its separation from the matrices. The results were ...
First Voltammetric Method of Phenoxyethanol Determination in Pharmaceutical and Cosmetic Preparations
Journal of The Electrochemical Society
International Journal of Electrochemical Science
Electrochemical behavior of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) was... more Electrochemical behavior of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) was investigated by cyclic (CV), linear sweep (LSV) and differential pulse voltammetry (DPV) in glacial acetic acid solutions in order to develop a new method for determination of these synthetic antioxidants. A glassy carbon electrode (GC) and a carbon fiber disk microelectrode (CF) were used as working electrodes. Voltammograms recorded at these electrodes show well-defined single waves or peaks attributed to the oxidation of BHA and BHT which proceeds with an irreversible exchange of two electrons. A separation of about 0.24 V between the peak potentials recorded using DPV in their binary mixtures was obtained. Wide linearity ranges were achieved: 0.03-594.62, 0.18-921.37 mg L-1 and low limits of detection were 0.01, 0.06 mg L-1 for butylated hydroxyanisole and butylated hydroxytoluene, respectively. The results obtained indicate that DPV at CF microelectrode allows sensitive, precise, accurate, and fast determination of BHA and BHT, alone or in their mixture in pharmaceuticals without the need for their separation from the matrices, and can be an analytical alternative for existing methods.
Molecules
Thymol and carvacrol—the components of herbal spices—are known for their broad biological activit... more Thymol and carvacrol—the components of herbal spices—are known for their broad biological activity as antimicrobials and antioxidants. For this reason, it is important to develop new methods for their determination in plant material. A simple, rapid, and sensitive method for determination of total content of these analytes in herbal spices using differential pulse voltammetry (DPV) has been developed. The basis of the research is the oxidation process of isopropylmethylphenols on a platinum microelectrode in glacial acetic acid containing acetonitrile (20%, v/v) and 0.1 mol L−1 sodium perchlorate as the supporting electrolyte. Linear voltammetric responses for thymol and carvacrol were obtained in a wide concentration range from 0.39–1105 and 0.47–640 µg mL−1, with a low detection limit of 0.04 and 0.05 µg mL−1, respectively. The analysis was performed using the multiple standard addition method. The results of the voltammetric determination are in good agreement with the data of th...
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Papers by Magdalena Jakubczyk