TY  - JOUR
AU  - Šovrc, Ľubomír
AU  - Cinková, Kristína
AU  - Samphao, Anchalee
AU  - Stanković, Dalibor
AU  - Mehmeti, Eda
AU  - Kalcher, Kurt
PY  - 2015
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/1702
AB  - A novel analytical approach for the sensitive determination of a beta-carboline alkaloid, harmaline, was developed using pulse voltammetric techniques with a boron-doped diamond electrode. Cyclic voltammetry showed two irreversible oxidation peaks at about +0.90 and +1.20 V (vs. Ag/AgCl) in Britton-Robinson buffer solution at pH 5. Under optimized experimental conditions, differential pulse and square-wave voltammetry were elaborated for the determination of harmaline in a linear concentration range from 0.2 to 100.7 and from 0.4 to 104.5 mu mol L-1, respectively, with detection limits of 0.08 and 0.2 mu mol L-1, respectively. The practical feasibility of the developed method was demonstrated by quantification of harmaline in the extracts of natural food products such as Syrian rue (Peganum harmala, also known as esphant, harmal, yiizerlik) seeds, locally used as condiment and medicine in Turkey and the Near and Middle East, and the South American shamanic drink component Ayahuasca liane (Banisteriopsis caapi) with results in good agreement with those obtained by high-performance liquid chromatography as a reference method. The proposed sensor represents an effective electrochemical tool and inexpensive alternative for quality control analysis of food products containing harmaline.
PB  - Elsevier Science Sa, Lausanne
T2  - Journal of Electroanalytical Chemistry
T1  - Voltammetric determination of harmaline in natural food products using boron-doped diamond electrode
VL  - 744
SP  - 37
EP  - 44
DO  - 10.1016/j.jelechem.2015.03.004
ER  - 

@article{
author = "Šovrc, Ľubomír and Cinková, Kristína and Samphao, Anchalee and Stanković, Dalibor and Mehmeti, Eda and Kalcher, Kurt",
year = "2015",
abstract = "A novel analytical approach for the sensitive determination of a beta-carboline alkaloid, harmaline, was developed using pulse voltammetric techniques with a boron-doped diamond electrode. Cyclic voltammetry showed two irreversible oxidation peaks at about +0.90 and +1.20 V (vs. Ag/AgCl) in Britton-Robinson buffer solution at pH 5. Under optimized experimental conditions, differential pulse and square-wave voltammetry were elaborated for the determination of harmaline in a linear concentration range from 0.2 to 100.7 and from 0.4 to 104.5 mu mol L-1, respectively, with detection limits of 0.08 and 0.2 mu mol L-1, respectively. The practical feasibility of the developed method was demonstrated by quantification of harmaline in the extracts of natural food products such as Syrian rue (Peganum harmala, also known as esphant, harmal, yiizerlik) seeds, locally used as condiment and medicine in Turkey and the Near and Middle East, and the South American shamanic drink component Ayahuasca liane (Banisteriopsis caapi) with results in good agreement with those obtained by high-performance liquid chromatography as a reference method. The proposed sensor represents an effective electrochemical tool and inexpensive alternative for quality control analysis of food products containing harmaline.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Journal of Electroanalytical Chemistry",
title = "Voltammetric determination of harmaline in natural food products using boron-doped diamond electrode",
volume = "744",
pages = "37-44",
doi = "10.1016/j.jelechem.2015.03.004"
}

Šovrc, Ľ., Cinková, K., Samphao, A., Stanković, D., Mehmeti, E.,& Kalcher, K.. (2015). Voltammetric determination of harmaline in natural food products using boron-doped diamond electrode. in Journal of Electroanalytical Chemistry
Elsevier Science Sa, Lausanne., 744, 37-44.
https://doi.org/10.1016/j.jelechem.2015.03.004

Šovrc Ľ, Cinková K, Samphao A, Stanković D, Mehmeti E, Kalcher K. Voltammetric determination of harmaline in natural food products using boron-doped diamond electrode. in Journal of Electroanalytical Chemistry. 2015;744:37-44.
doi:10.1016/j.jelechem.2015.03.004 .

Šovrc, Ľubomír, Cinková, Kristína, Samphao, Anchalee, Stanković, Dalibor, Mehmeti, Eda, Kalcher, Kurt, "Voltammetric determination of harmaline in natural food products using boron-doped diamond electrode" in Journal of Electroanalytical Chemistry, 744 (2015):37-44,
https://doi.org/10.1016/j.jelechem.2015.03.004 . .

TY  - JOUR
AU  - Šovrc, Ľubomír
AU  - Stanković, Dalibor
AU  - Mehmeti, Eda
AU  - Kalcher, Kurt
PY  - 2014
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/1794
AB  - For the first time, a simple and sensitive analytical method for the direct determination of yohimbine is presented using differential pulse voltammetry with a boron-doped diamond electrode. Two irreversible oxidation peaks, a distinct one at +0.80 and a second poorly-defined one at +1.65 V, were observed when cyclic voltammetry was carried out in Britton-Robinson buffer solution at pH 7 (vs. Ag/AgCl). With optimized differential pulse voltammetric parameters (pulse amplitude 100 mV, pulse time 25 ms, step potential 5 mV and scan rate 10 mV s(-1)), the current response of yohimbine at +0.80 V was linearly proportional to the concentration in the range from 0.25 to 90.9 mu mol L-1 with a low detection limit of 0.13 mu mol L-1 (0.046 mg L-1) and a good repeatability (relative standard deviation of 2.5% at 18.4 mu mol L-1 for n = 6). The practical applicability of the developed method was demonstrated by the assessment of the total content of yohimbine in extracts of the primary bark of natural aphrodisiacs such as Pausinystalia yohimbe and Rauvolfia serpentina with recoveries in the range of 92-97%. The proposed electrochemical procedure represents an inexpensive and effective analytical alternative for the quality control analysis of products containing yohimbine and other biologically and structurally related alkaloids used as natural dietary supplements.
PB  - Royal Soc Chemistry, Cambridge
T2  - Analytical Methods
T1  - Sensitive electrochemical determination of yohimbine in primary bark of natural aphrodisiacs using boron-doped diamond electrode
VL  - 6
IS  - 13
SP  - 4853
EP  - 4859
DO  - 10.1039/c4ay00704b
ER  - 

@article{
author = "Šovrc, Ľubomír and Stanković, Dalibor and Mehmeti, Eda and Kalcher, Kurt",
year = "2014",
abstract = "For the first time, a simple and sensitive analytical method for the direct determination of yohimbine is presented using differential pulse voltammetry with a boron-doped diamond electrode. Two irreversible oxidation peaks, a distinct one at +0.80 and a second poorly-defined one at +1.65 V, were observed when cyclic voltammetry was carried out in Britton-Robinson buffer solution at pH 7 (vs. Ag/AgCl). With optimized differential pulse voltammetric parameters (pulse amplitude 100 mV, pulse time 25 ms, step potential 5 mV and scan rate 10 mV s(-1)), the current response of yohimbine at +0.80 V was linearly proportional to the concentration in the range from 0.25 to 90.9 mu mol L-1 with a low detection limit of 0.13 mu mol L-1 (0.046 mg L-1) and a good repeatability (relative standard deviation of 2.5% at 18.4 mu mol L-1 for n = 6). The practical applicability of the developed method was demonstrated by the assessment of the total content of yohimbine in extracts of the primary bark of natural aphrodisiacs such as Pausinystalia yohimbe and Rauvolfia serpentina with recoveries in the range of 92-97%. The proposed electrochemical procedure represents an inexpensive and effective analytical alternative for the quality control analysis of products containing yohimbine and other biologically and structurally related alkaloids used as natural dietary supplements.",
publisher = "Royal Soc Chemistry, Cambridge",
journal = "Analytical Methods",
title = "Sensitive electrochemical determination of yohimbine in primary bark of natural aphrodisiacs using boron-doped diamond electrode",
volume = "6",
number = "13",
pages = "4853-4859",
doi = "10.1039/c4ay00704b"
}

Šovrc, Ľ., Stanković, D., Mehmeti, E.,& Kalcher, K.. (2014). Sensitive electrochemical determination of yohimbine in primary bark of natural aphrodisiacs using boron-doped diamond electrode. in Analytical Methods
Royal Soc Chemistry, Cambridge., 6(13), 4853-4859.
https://doi.org/10.1039/c4ay00704b

Šovrc Ľ, Stanković D, Mehmeti E, Kalcher K. Sensitive electrochemical determination of yohimbine in primary bark of natural aphrodisiacs using boron-doped diamond electrode. in Analytical Methods. 2014;6(13):4853-4859.
doi:10.1039/c4ay00704b .

Šovrc, Ľubomír, Stanković, Dalibor, Mehmeti, Eda, Kalcher, Kurt, "Sensitive electrochemical determination of yohimbine in primary bark of natural aphrodisiacs using boron-doped diamond electrode" in Analytical Methods, 6, no. 13 (2014):4853-4859,
https://doi.org/10.1039/c4ay00704b . .

TY  - JOUR
AU  - Šovrc, Ľubomír
AU  - Stanković, Dalibor
AU  - Kalcher, Kurt
PY  - 2014
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/1514
AB  - A sensitive, selective and reliable electrochemical method for the determination of nicotine using differential pulse voltammetry on a bare boron-doped diamond electrode has been developed. Nicotine yielded a single oxidation peak at a highly positive potential of +1.45 V (vs. Ag/AgCl/3 M KCl) in Britton-Robinson buffer solution at pH 8. The influence of supporting electrolyte, pH and scan rate on the current response of NIC was investigated. At optimized experimental conditions, a linear relation between peak current and concentration of nicotine was found for the range from 0.5 to 200 mu M (0.08-32.9 mg L-1) with a detection limit of 0.3 mu M (0.05 mg L-1) and a good repeatability (relative standard deviation of 2.1% at 25 mu M concentration level, n = 10) was achieved without any electrode surface modification. The practical usefulness of the developed procedure was successfully demonstrated with the determination of nicotine in tobacco products and anti-smoking pharmaceuticals with results similar to those obtained by a high-performance liquid chromatography and to the contents declared by the manufacturer, respectively. Prior to analysis, the sample pretreatment includes only sonication and/or simple liquid-liquid extraction. The proposed sensor represents an effective electrochemical tool and a promising alternative for quality control analysis of products in tobacco and pharmaceutical industry. (C) 2013 Elsevier B.V. All rights reserved.
PB  - Elsevier Science Sa, Lausanne
T2  - Diamond and Related Materials
T1  - Boron-doped diamond electrochemical sensor for sensitive determination of nicotine in tobacco products and anti-smoking pharmaceuticals
VL  - 42
SP  - 1
EP  - 7
DO  - 10.1016/j.diamond.2013.11.012
ER  - 

@article{
author = "Šovrc, Ľubomír and Stanković, Dalibor and Kalcher, Kurt",
year = "2014",
abstract = "A sensitive, selective and reliable electrochemical method for the determination of nicotine using differential pulse voltammetry on a bare boron-doped diamond electrode has been developed. Nicotine yielded a single oxidation peak at a highly positive potential of +1.45 V (vs. Ag/AgCl/3 M KCl) in Britton-Robinson buffer solution at pH 8. The influence of supporting electrolyte, pH and scan rate on the current response of NIC was investigated. At optimized experimental conditions, a linear relation between peak current and concentration of nicotine was found for the range from 0.5 to 200 mu M (0.08-32.9 mg L-1) with a detection limit of 0.3 mu M (0.05 mg L-1) and a good repeatability (relative standard deviation of 2.1% at 25 mu M concentration level, n = 10) was achieved without any electrode surface modification. The practical usefulness of the developed procedure was successfully demonstrated with the determination of nicotine in tobacco products and anti-smoking pharmaceuticals with results similar to those obtained by a high-performance liquid chromatography and to the contents declared by the manufacturer, respectively. Prior to analysis, the sample pretreatment includes only sonication and/or simple liquid-liquid extraction. The proposed sensor represents an effective electrochemical tool and a promising alternative for quality control analysis of products in tobacco and pharmaceutical industry. (C) 2013 Elsevier B.V. All rights reserved.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Diamond and Related Materials",
title = "Boron-doped diamond electrochemical sensor for sensitive determination of nicotine in tobacco products and anti-smoking pharmaceuticals",
volume = "42",
pages = "1-7",
doi = "10.1016/j.diamond.2013.11.012"
}

Šovrc, Ľ., Stanković, D.,& Kalcher, K.. (2014). Boron-doped diamond electrochemical sensor for sensitive determination of nicotine in tobacco products and anti-smoking pharmaceuticals. in Diamond and Related Materials
Elsevier Science Sa, Lausanne., 42, 1-7.
https://doi.org/10.1016/j.diamond.2013.11.012

Šovrc Ľ, Stanković D, Kalcher K. Boron-doped diamond electrochemical sensor for sensitive determination of nicotine in tobacco products and anti-smoking pharmaceuticals. in Diamond and Related Materials. 2014;42:1-7.
doi:10.1016/j.diamond.2013.11.012 .

Šovrc, Ľubomír, Stanković, Dalibor, Kalcher, Kurt, "Boron-doped diamond electrochemical sensor for sensitive determination of nicotine in tobacco products and anti-smoking pharmaceuticals" in Diamond and Related Materials, 42 (2014):1-7,
https://doi.org/10.1016/j.diamond.2013.11.012 . .