A simple and rapid electrochemical determination of pungency: Application to aqueous and ethanolic extracts of Capsicum annuum cubana red

Chili peppers are rich in ascorbic acid and capsaicin. In this article is proposed an easy, fast, sensitive, and inexpensive method for determining the pungency and content of ascorbic acid in chili pepper extracts. The voltammetric (cyclic and differential pulse) behavior of capsaicin on a glassy carbon electrode has been evaluated at different pH values. A calibration curve has been obtained for the peak current, IP, of capsaicin as a function of the capsaicin concentration, C, in differential pulse voltammetry in phosphate buffer solution at pH 7.0: IP(µA) = 0.0147 (±5.346·10−3) + 0.0507 (±8.984·10−4) C(µM), with limit of detection, LOD = 0.198µM, limit of quantification, LOQ = 0.660µM, and dynamic linear range from 0.660 to 20.9 µM. A variant of the standard addition method has been used for simultaneous determination of the pungency and ascorbic acid content of extracts of Capsicum annuum cubana red. In this case, the calibration for ascorbic acid was I(µA) = 0.467 (±0.012) + 2.039·10−3 (±4.601·10−5) VAA(L)), with LOD = 17.56 µL, LOQ = 58.55 µL, and dynamic linear range from 58.6 to 500 µL, being VAA the volume of 10-mM ascorbic acid added to 50 mL of solution. The ascorbic acid content was compared to that of a sweet pepper. The method is cheap, simple, and fast (30 min vs c.a. 2 h compared to the spectrophotometric method), its sensitivity being comparable to other more expensive and/or more laborious methods.

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Sensitive Determination of Epinephrine in the Presence of Ascorbic Acid at Poly(diphenylamine sulfonic acid) Modified Sensor

Sensor Letters ◽

10.1166/sl.2020.4228 ◽

2020 ◽

Vol 18 (4) ◽

pp. 253-258

Author(s):

Gamze Erdoğdu

Keyword(s):

Ascorbic Acid ◽

Sulfonic Acid ◽

Limit Of Detection ◽

Phosphate Buffer Solution ◽

Differential Pulse ◽

Buffer Solution ◽

Sensitive Determination ◽

Pulse Voltammetry ◽

Modified Sensor

A sensitive and simple modified sensor was prepared by electrodeposition of diphenylamine sulfonic acid (DPSA) to the glassy carbon electrode surface by cyclic voltammetry (CV) technique. The electrooxidation of epinephrine (EP) was accomplished by CV and differential pulse voltammetry at poly(DPSA) modified sensor. As a result of the findings, the current values were enhanced and both substances were separated at the modified sensor compared to the bare electrode. There was linearly between the oxidation current and concentration of EP from 0.2 to 100 μM in phosphate buffer solution at pH 7.0. The limit of detection was 5.0 nM and the sensitivity was 0.4205 μA/μM. The determination of EP was successfully and satisfactorily carried out in real samples such as human blood serum and urine at the poly(DPSA) sensor. To the best knowledge of this work, this is the first study that detect the EP in the presence of ascorbic acid at poly(DPSA) sensor in the literature.

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Electrochemical Determination of Norepinephrine at Poly (p-aminobenzenesulfonic Acid) Modified Sensor

Current Pharmaceutical Analysis ◽

10.2174/1573412915666190212160442 ◽

2020 ◽

Vol 16 (5) ◽

pp. 591-600

Author(s):

Şevket Zişan Yağcı ◽

Ebru Kuyumcu Savan ◽

Gamze Erdoğdu

Keyword(s):

Ascorbic Acid ◽

Limit Of Detection ◽

Phosphate Buffer Solution ◽

Differential Pulse ◽

Electrochemical Determination ◽

Buffer Solution ◽

Oxidation Current ◽

Pulse Voltammetry ◽

Modified Sensor

Objective: In this study, it was aimed to prepare an electrochemical sensor capable of assigning Norepinephrine in the presence of an interference such as ascorbic acid. Methods: A sensitive modified sensor was prepared by electrodeposition of p-aminobenzenesulfonic acid (p-ABSA) to the glassy carbon electrode by cyclic voltammetry. The electrooxidation of Norepinephrine was accomplished by cyclic and differential pulse voltammetry. Results: The current values were enhanced and the peak potentials of Norepinephrine and ascorbic acid were separated at the sensor compared to the bare electrode. There was linearity between the oxidation current and concentration of Norepinephrine ranging from 0.5 to 99.8 μM in phosphate buffer solution at pH 7.0. The limit of detection was 10.0 nM and the sensitivity was 0.455 μA/μM. Conclusion: The determination of Norepinephrine was successfully performed in real samples such as blood serum and urine at the poly (p-ABSA) sensor. To the best of our knowledge, this is the first study to detect Norepinephrine in the presence of ascorbic acid at poly (p-ABSA) modified sensor in the literature.

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High-Pressure Liquid Chromatographic Determination of Ascorbic Acid in Cooked Sausages

Journal of Food Protection ◽

10.4315/0362-028x-65.11.1771 ◽

2002 ◽

Vol 65 (11) ◽

pp. 1771-1774 ◽

Cited By ~ 14

Author(s):

FELICIDAD VALLS ◽

M. TERESA SANCHO ◽

MIGUEL A. FERNÁNDEZ-MUIÑO ◽

SARA ALONSO-TORRE ◽

MARTÍN A. CHECA

Keyword(s):

High Pressure ◽

Ascorbic Acid ◽

Acid Content ◽

Phosphate Buffer Solution ◽

Potassium Phosphate ◽

Ascorbic Acid Content ◽

Uv Detection ◽

Metaphosphoric Acid ◽

Potassium Phosphate Buffer Solution

The purpose of this paper was to study and optimize both extraction and high-pressure liquid chromatography (HPLC)–UV detection procedures to develop a proper method for the determination of ascorbic acid content in cooked sausages. A simple and sensitive reversed-phase HPLC method for the NH2-bonded phase has been described for the determination of ascorbic acid content in cooked sausages. Various extracting agents were tested to solubilize the vitamin, with 5% (wt/vol) metaphosphoric acid giving the best results. Samples were chromatographed with UV detection at 248 nm on a 25-cm Spherisorb NH2 cartridge with a 0.4-cm inside diameter with a mixture of 0.02 M potassium phosphate buffer solution (pH 3.6) and acetonitrile (40:60, vol/vol) for the mobile phase. The method's precision within a day was 1.2%, and its precision between days was 3.8%. The detection limit was 1.6 mg/100 g. Recovery ranged from 91.4 to 96.2% for ascorbic acid added to meat samples. Twenty samples of six different products were analyzed in duplicate. For the samples analyzed, the mean value for ascorbic acid ranged between 21.555 and 24.899 mg/100 g of fresh weight.

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An Electrochemical Sensor Based On Graphite Electrode Modified With Silica Containing 1-N-Propyl-3-Methylimidazolium Species For Determination Of Ascorbic Acid

METHODS AND OBJECTS OF CHEMICAL ANALYSIS ◽

10.17721/moca.2019.5-14 ◽

2019 ◽

Vol Vol. 14, No.1 ◽

pp. 5-14 ◽

Cited By ~ 1

Author(s):

Anastasiya Tkachenko ◽

Mykyta Onizhuk ◽

Oleg Tkachenko ◽

Leliz T. Arenas ◽

Edilson V. Benvenutt ◽

...

Keyword(s):

Ascorbic Acid ◽

Cyclic Voltammetry ◽

Electrochemical Sensor ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Pharmaceutical Formulations ◽

Differential Pulse ◽

Long Term Stability ◽

Diffusion Limited

In the present study, an electrochemical sensor based on the electrode (SiMImCl/C) consisting of graphite and silica, grafted with 1-n-propyl-3-methylimidazolium chloride was used for ascorbic acid (AA) quantification in pharmaceuticals and food formulations. Cyclic voltammetry and electrochemical impedance spectroscopy were applied for electrochemical characterization of the SiMImCl/C electrode. The cyclic voltammetry study revealed that the oxidation of AA on this electrode is an irreversible process, realized by adsorption and diffusion limited step. The differential pulse voltammetry was applied to develop a procedure for the AA determination. The linear range was found to be 0.3–170 μmol L-1 and the limit of detection – 0.1 μmol L-1. The proposed SiMImCl/C electrode has long term stability and does not show electrochemical activity towards the analytes, which commonly coexist with AA. The sensor was successfully used for quantification of AA in food and pharmaceutical formulations.

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Carvacrol electrochemical reaction characteristics on screen printed electrode modified with La2O3/Co3O4 nanocomposite

Journal of Electrochemical Science and Engineering ◽

10.5599/jese.637 ◽

2019 ◽

Vol 9 (2) ◽

pp. 113-123 ◽

Cited By ~ 4

Author(s):

Sayed Zia Mohammadi ◽

Hadi Beitollahi ◽

Tahereh Rohani ◽

Hossein Allahabadi

Keyword(s):

Limit Of Detection ◽

Phosphate Buffer Solution ◽

Differential Pulse ◽

Co3o4 Nanoparticles ◽

Electrochemical Characteristics ◽

Screen Printed Electrode ◽

Buffer Solution ◽

Voltammetric Techniques ◽

Screen Printed

Electrochemical characteristics of carvacrol were investigated on a screen-printed electrode (SPE) modified with La2O3/Co3O4 nanocomposite by using voltammetric techniques, which displayed a well-defined peak for sensitive carvacrol determination in phosphate buffer solution (PBS) at pH 7.0. La2O3/Co3O4 nanoparticles demonstrated suitable catalytic activity for carvacrol determination by differential pulse voltammetry (DPV) technique. Besides, determination of carvacrol in a real samples was recognized in the light of electrochemical findings and a validated voltammetric technique for quantitative analysis of carvacrol in a real formulation was proposed. The DPV peak currents were found to be linear in the concentration range of 10.0 to 800.0 μM. The limit of detection (LOD) was found to be 1.0 μM.

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