TY  - JOUR
AU  - Švorc, Lubomir
AU  - Haššo, Marek
AU  - Sarakhman, Olha
AU  - Kianičkova, Kristina
AU  - Stanković, Dalibor M.
AU  - Otrisal, Pavel
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0026265X18307367
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7791
AB  - In the present paper, a miniaturized boron-doped diamond electrode (BDDE) is proposed as a progressive electrochemical sensor for simple, fast and reliable quantification of dimethylxanthine alkaloid, theobromine (TB). Using cyclic voltammetry, the studied xanthine provided one well-shaped, irreversible and diffusion-controlled oxidation peak at relatively high potentials (+1.2 V vs. Ag/AgCl/3 M KCl reference electrode) in the presence of 0.1 M H2SO4. After selection of suitable experimental conditions, the linear calibration curves for TB were obtained in the concentration range from 0.99 up to 54.5 μM with the sensitivity of 0.07 μA/μM providing both differential pulse (DPV) and square-wave voltammetric (SWV) techniques, respectively. The elaborated voltammetric protocol yielded low detection limits of 0.42 and 0.51 μM accompanied by adequate intra-day repeatability (relative standard deviation of 2.5 and 1.7%) using DPV and SWV procedure, respectively. The interference study revealed the reasonable selectivity when taking the target food samples into account. The practical applicability of the voltammetric protocol using a miniaturized BDDE was verified in the analysis of six commercially available brands of chocolate products with the determined mass percentages of TB ranging from 0.75 to 2.24% and from 0.69 to 2.15% using DPV and SWV procedure, respectively. The obtained results were also in a good agreement with those achieved by reference titration method with potentiometric indication. The progressive electrochemical sensor based on a miniaturized BDDE has appeared to be an attractive candidate for practical applications in food quality control. Besides, the proposed voltammetric protocol presents advantages when compared to others techniques (e.g. chromatography), concerning simplicity, cost, speed of analysis, waste generation (environmentally friendly) and samples pretreatment (only dilution in electrolyte solution prior to analysis). © 2018 Elsevier B.V.
T2  - Microchemical Journal
T1  - A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode
VL  - 142
SP  - 297
EP  - 304
DO  - 10.1016/j.microc.2018.07.007
ER  - 

@article{
author = "Švorc, Lubomir and Haššo, Marek and Sarakhman, Olha and Kianičkova, Kristina and Stanković, Dalibor M. and Otrisal, Pavel",
year = "2018",
abstract = "In the present paper, a miniaturized boron-doped diamond electrode (BDDE) is proposed as a progressive electrochemical sensor for simple, fast and reliable quantification of dimethylxanthine alkaloid, theobromine (TB). Using cyclic voltammetry, the studied xanthine provided one well-shaped, irreversible and diffusion-controlled oxidation peak at relatively high potentials (+1.2 V vs. Ag/AgCl/3 M KCl reference electrode) in the presence of 0.1 M H2SO4. After selection of suitable experimental conditions, the linear calibration curves for TB were obtained in the concentration range from 0.99 up to 54.5 μM with the sensitivity of 0.07 μA/μM providing both differential pulse (DPV) and square-wave voltammetric (SWV) techniques, respectively. The elaborated voltammetric protocol yielded low detection limits of 0.42 and 0.51 μM accompanied by adequate intra-day repeatability (relative standard deviation of 2.5 and 1.7%) using DPV and SWV procedure, respectively. The interference study revealed the reasonable selectivity when taking the target food samples into account. The practical applicability of the voltammetric protocol using a miniaturized BDDE was verified in the analysis of six commercially available brands of chocolate products with the determined mass percentages of TB ranging from 0.75 to 2.24% and from 0.69 to 2.15% using DPV and SWV procedure, respectively. The obtained results were also in a good agreement with those achieved by reference titration method with potentiometric indication. The progressive electrochemical sensor based on a miniaturized BDDE has appeared to be an attractive candidate for practical applications in food quality control. Besides, the proposed voltammetric protocol presents advantages when compared to others techniques (e.g. chromatography), concerning simplicity, cost, speed of analysis, waste generation (environmentally friendly) and samples pretreatment (only dilution in electrolyte solution prior to analysis). © 2018 Elsevier B.V.",
journal = "Microchemical Journal",
title = "A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode",
volume = "142",
pages = "297-304",
doi = "10.1016/j.microc.2018.07.007"
}

Švorc, L., Haššo, M., Sarakhman, O., Kianičkova, K., Stanković, D. M.,& Otrisal, P.. (2018). A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode. in Microchemical Journal, 142, 297-304.
https://doi.org/10.1016/j.microc.2018.07.007

Švorc L, Haššo M, Sarakhman O, Kianičkova K, Stanković DM, Otrisal P. A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode. in Microchemical Journal. 2018;142:297-304.
doi:10.1016/j.microc.2018.07.007 .

Švorc, Lubomir, Haššo, Marek, Sarakhman, Olha, Kianičkova, Kristina, Stanković, Dalibor M., Otrisal, Pavel, "A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode" in Microchemical Journal, 142 (2018):297-304,
https://doi.org/10.1016/j.microc.2018.07.007 . .

TY  - JOUR
AU  - Švorc, Lubomir
AU  - Strežova, Ivana
AU  - Kianičkova, Kristina
AU  - Stanković, Dalibor M.
AU  - Otrisal, Pavel
AU  - Samphao, Anchalee
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S1572665718303783
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7698
AB  - Herein, an advanced electroanalytical approach for the determination of ibuprofen based on the use of a bare and electrochemically untreated boron-doped diamond electrode is presented. Cyclic voltammetric study revealed that the electrode reaction of the analyte was manifested by the presence of well-shaped irreversible and diffusion-driven oxidation peak at very high potential (+1.75 V vs. Ag/AgCl/3 mol L−1KCl reference electrode) in 1 mol L−1perchloric acid. After optimization of experimental conditions, the peak current of ibuprofen was proportionally linear from 9.49 × 10−7to 6.69 × 10−5mol L−1providing both differential pulse (DPV) and square-wave voltammetric (SWV) techniques, respectively. The elaborated electroanalytical protocol rendered low detection limits of 4.1 × 10−7and 9.3 × 10−7mol L−1in association with favourable intra-day repeatability (relative standard deviation of 3.6 and 4.6%) using DPV and SWV procedures, respectively. The effect of interfering compounds such as ascorbic acid, dopamine, caffeine, uric acid and glucose on the current response of ibuprofen was explored in details. The usefulness of the proposed approach was verified in the analysis of a variety of commercial brands of pharmaceuticals and spiked human urine samples with the significant range of recovery percentages (for pharmaceuticals: 99.8–107.5% and 99.8–105.0% by DPV and SWV, for urine: 95–107% and 97–103% by DPV and SWV). Taking these features into account, the developed protocol may be exploited as a novel, simple and efficient tool in drug quality control analysis and analysis of biological samples. In addition, a bare and electrochemically untreated boron-doped diamond electrode may be applied as a progressive electrochemical sensor and helpful alternative to previously utilized electrochemical platforms in this field.
T2  - Journal of Electroanalytical Chemistry
T1  - An advanced approach for electrochemical sensing of ibuprofen in pharmaceuticals and human urine samples using a bare boron-doped diamond electrode
VL  - 822
SP  - 144
EP  - 152
DO  - 10.1016/j.jelechem.2018.05.026
ER  - 

@article{
author = "Švorc, Lubomir and Strežova, Ivana and Kianičkova, Kristina and Stanković, Dalibor M. and Otrisal, Pavel and Samphao, Anchalee",
year = "2018",
abstract = "Herein, an advanced electroanalytical approach for the determination of ibuprofen based on the use of a bare and electrochemically untreated boron-doped diamond electrode is presented. Cyclic voltammetric study revealed that the electrode reaction of the analyte was manifested by the presence of well-shaped irreversible and diffusion-driven oxidation peak at very high potential (+1.75 V vs. Ag/AgCl/3 mol L−1KCl reference electrode) in 1 mol L−1perchloric acid. After optimization of experimental conditions, the peak current of ibuprofen was proportionally linear from 9.49 × 10−7to 6.69 × 10−5mol L−1providing both differential pulse (DPV) and square-wave voltammetric (SWV) techniques, respectively. The elaborated electroanalytical protocol rendered low detection limits of 4.1 × 10−7and 9.3 × 10−7mol L−1in association with favourable intra-day repeatability (relative standard deviation of 3.6 and 4.6%) using DPV and SWV procedures, respectively. The effect of interfering compounds such as ascorbic acid, dopamine, caffeine, uric acid and glucose on the current response of ibuprofen was explored in details. The usefulness of the proposed approach was verified in the analysis of a variety of commercial brands of pharmaceuticals and spiked human urine samples with the significant range of recovery percentages (for pharmaceuticals: 99.8–107.5% and 99.8–105.0% by DPV and SWV, for urine: 95–107% and 97–103% by DPV and SWV). Taking these features into account, the developed protocol may be exploited as a novel, simple and efficient tool in drug quality control analysis and analysis of biological samples. In addition, a bare and electrochemically untreated boron-doped diamond electrode may be applied as a progressive electrochemical sensor and helpful alternative to previously utilized electrochemical platforms in this field.",
journal = "Journal of Electroanalytical Chemistry",
title = "An advanced approach for electrochemical sensing of ibuprofen in pharmaceuticals and human urine samples using a bare boron-doped diamond electrode",
volume = "822",
pages = "144-152",
doi = "10.1016/j.jelechem.2018.05.026"
}

Švorc, L., Strežova, I., Kianičkova, K., Stanković, D. M., Otrisal, P.,& Samphao, A.. (2018). An advanced approach for electrochemical sensing of ibuprofen in pharmaceuticals and human urine samples using a bare boron-doped diamond electrode. in Journal of Electroanalytical Chemistry, 822, 144-152.
https://doi.org/10.1016/j.jelechem.2018.05.026

Švorc L, Strežova I, Kianičkova K, Stanković DM, Otrisal P, Samphao A. An advanced approach for electrochemical sensing of ibuprofen in pharmaceuticals and human urine samples using a bare boron-doped diamond electrode. in Journal of Electroanalytical Chemistry. 2018;822:144-152.
doi:10.1016/j.jelechem.2018.05.026 .

Švorc, Lubomir, Strežova, Ivana, Kianičkova, Kristina, Stanković, Dalibor M., Otrisal, Pavel, Samphao, Anchalee, "An advanced approach for electrochemical sensing of ibuprofen in pharmaceuticals and human urine samples using a bare boron-doped diamond electrode" in Journal of Electroanalytical Chemistry, 822 (2018):144-152,
https://doi.org/10.1016/j.jelechem.2018.05.026 . .