Voltammetric Determination of Anethole on La2O3/CPE and BDDE

New electroanalytical method for the determination of trans-anethole in spices and sweets

A completely new method for the determination of trans-anethole (TAN) based on the anodic oxidation of this flavouring substance in pure acetonitrile using differential-pulse voltammetry has been developed. A nonaqueous carbon paste electrode bulk-modified with solid sodium dodecyl sulphate of 40 % (w/w) content was chosen as optimum. To propose TAN electrode reaction mechanism, its electrochemical behaviour was investigated at glassy carbon electrode in nonaqueous media. At optimum working conditions, the current response could be calibrated within a linear range 2-200 µmolL^-1 TAN, a coefficient of determination of 0.9971, a sensitivity of 0.1122µALµmol^-1_, and a detection limit of 0.7 µmolL^-1. A satisfactory precision (relative standard deviation of 4 %) has been achieved. The validation performed by analysis of spices and sweets provided comparable results with reference reverse-phase HPLC with spectrophotometric detection, thus confirming the practical use of the developed voltammetric method in food analysis.

Electrochemical Characterization of the Antioxidant Properties of Medicinal Plants and Products: A Review

Medicinal plants are an important source of bioactive compounds with a wide spectrum of practically useful properties. Various types of antioxidants synthesized in plants are the reasons for their application in medicine, phytotherapy, and aromatherapy. Therefore, reliable, simple, cost-effective, eco-friendly, and rapid methods for the evaluation of antioxidant properties of medicinal plants and products on their basis are required. Electrochemical methods based on electron transfer reactions are promising tools to solve this problem. Total antioxidant parameters and individual antioxidant quantification can be achieved using suitable electrochemical techniques. The analytical capabilities of constant-current coulometry, potentiometry, various types of voltammetry, and chrono methods in the evaluation of total antioxidant parameters of medicinal plants and plant-derived products are presented. The advantages and limitations of methods in comparison to each other and traditional spectroscopic methods are discussed. The possibility to use electrochemical detection of the antioxidants via reactions with oxidants or radicals (N- and O-centered) in solution, with stable radicals immobilized on the electrode surface, via oxidation of antioxidants on a suitable electrode, allows the study of various mechanisms of antioxidant actions occurring in living systems. Attention is also paid to the individual or simultaneous electrochemical determination of antioxidants in medicinal plants using chemically modified electrodes.

Simultaneous Determination of Fenchone and Trans-Anethole in Essential Oils and Methanolic Extracts of Foeniculum vulgare Mill. Fruits Obtained from Different Geographical Regions Using GC-MS Approach

The gas chromatography–mass spectrometry (GC-MS) approach is established for the simultaneous determination of fenchone (FCO) and trans-anethole (TOH) in the essential oils and methanolic extracts of fennel (Foeniculum vulgare Mill.) fruits obtained from India (IND), Pakistan (PAK), and Saudi Arabia (SA). The simultaneous determination of FCO and TOH was performed via Agilent 190914S HP–5MS fused-silica capillary column (30 m × 250 µm ID, 0.25 µm film thickness). The proposed GC-MS approach was linear in the range of 0.10–50 µg/g for FCO and TOH. FCO’s detection (LOD) and quantification (LOQ) limits were calculated to be 0.04 and 0.12 µg/g, respectively. The LOD and LOQ values for TOH, on the other hand, were calculated to be 0.05 and 0.15 µg/g, respectively. In addition, the proposed GC-MS approach was accurate and precise for the simultaneous determination of FCO and TOH. The amount of FCO in essential oils of F. vulgare was computed as 0.021, 0.034, and 0.029 mg/g in the samples obtained from IND, PAK, and SA, respectively. The amount of TOH in the essential oils of F. vulgare was computed as 7.40, 14.8, and 10.2 mg/g in the samples obtained from IND, PAK, and SA, respectively. However, the amount of FCO in the methanolic extract of F. vulgare was estimated as 0.031, 0.021, and 0.057 mg/g in the samples obtained from IND, PAK, and SA, respectively. On the other hand, the amount of TOH in the methanolic extract of F. vulgare was estimated as 0.440, 0.498, and 1.74 mg/g in the samples obtained from IND, PAK, and SA, respectively. These findings suggested that the proposed GC-MS approach might be used to simultaneously determine the FCO and TOH in a variety of essential oils and plant extracts.

Determination of Trans-Anethole in Essential Oil, Methanolic Extract and Commercial Formulations of Foeniculum vulgare Mill Using a Green RP-HPTLC-Densitometry Method

Due to the lack of ecofriendly/green reversed-phase high-performance thin-layer chromatography (RP-HPTLC) methods for trans-anethole (TAL) and its simplicity over routine analytical techniques, there was a necessity to establish a suitable HPTLC methodology for the quantitative analysis of TAL. Therefore, the first objective of this research was to develop an accurate, rapid and green RP-HPTLC densitometry methodology for the quantitative analysis of TAL in essential oil, traditional and ultrasound-assisted extracts of Foeniculum vulgare Mill and commercial formulations. The second objective was to compare the traditional method of extraction of TAL with its ultrasound-assisted method of extraction. The chromatogram of TAL from essential oil and traditional and ultrasound-assisted extracts of fennel and commercial formulations was verified by recoding its single spectra at Rf = 0.31 ± 0.01 in comparison to standard TAL. The proposed analytical methodology has been found to be superior in terms of linearity, accuracy and precision compared to most of the reported analytical methods for TAL analysis. The amount of TAL in the essential oil of fennel was recorded as 8.82 mg per g of oil. The content of TAL in traditional extracts of fennel, formulation 1 (dietary supplement 1) and formulation 2 (dietary supplement 2), was recorded as 6.44, 4.88 and 4.48 mg per g, respectively. The amount of TAL in ultrasound-assisted extracts of fennel, formulation 1 and formulation 2, was recorded as 8.34, 6.46 and 5.81 mg per g, respectively. The ultrasound method of extraction of TAL was found to be better than the traditional method of extraction. The results of validation studies and phytochemical analysis showed that the proposed methodology could be efficiently utilized for the quantification of TAL in the wide range of products having TAL as a component.