Abstract: Assessing the quality of traditional African medicines (tradimedicines) requires the development of methods for the overall analysis of the pharmacologically active and/or chemically characteristic constituents present. The chromatographic profile of phytochemical metabolites is an important tool for the quality control of these drugs. Obtaining a rich chromatographic profile requires a process for the global extraction of phytochemicals. The objective of this work is to propose a profiling protocol by liquid chromatography for the evaluation of different solvents for the global extraction of phytochemical metabolites. The methodology was based on the establishment of an optimized reverse phase liquid chromatographic profile (good selectivity) of a pool of different extracts of a complex plant matrix (mixture of three plant drugs), applied to the determination of better solvents overall extraction of phytochemical metabolites (high number of chromatographic peaks detected). The results showed that 26 solvents (alone or in a binary, ternary and quaternary mixture) were tested; A better chromatographic profile was obtained in binary gradient (water-acetonitrile with added formic acid and ammonia) on C18 stationary phase and the best solvents for the overall extraction of phytochemical metabolites consisted of ternary mixtures of solvent (apolar/alcohol /water). This binary gradient liquid chromatography technique (water-acetonitrile with added formic acid and ammonia) on C18 stationary phase can be proposed for the global profiling of phytochemical metabolites with dichloromethane/ethanol/water or chloroform/ethanol/water mixtures as the overall extraction solvent.Abstract: Assessing the quality of traditional African medicines (tradimedicines) requires the development of methods for the overall analysis of the pharmacologically active and/or chemically characteristic constituents present. The chromatographic profile of phytochemical metabolites is an important tool for the quality control of these drugs. Obtaining a ...Show More
Abdoulkadri Ayouba Mahamane,Boubie Guel,Paul Louis Fabre
Issue:
Volume 10, Issue 4, December 2022
Pages:
74-79
Received:
11 October 2022
Accepted:
7 November 2022
Published:
14 November 2022
DOI:
10.11648/j.sjac.20221004.12
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Abstract: This paper describes a procedure for the determination of thallium by differential pulse anodic stripping voltammetry (DPASV) using a mercury film deposited on glassy carbon as the working electrode. The procedure has been optimized using experimental design methodology. The following results were obtained: deposition potential: -1000 mV, deposition time: 4 min, speed of the rotating disc electrode: 1000 rpm, pulse amplitude 80 mV. The response of the electrode towards thallium ions was then verified by establishing the calibration curve, which showed a good correlation coefficient of 0.9973 and the error between 5 successive determinations did not exceed 1.25%. The calculated limit of detection (LOD) is equal to 2.2 10-8 mol.L-1. A certified standard of thallium at 1 mg.L-1 is determined by the standard addition method and the recovery rate obtained is 99.14%. The remarkable electroanalytical performances of the glassy carbon/mercury thin film electrode make it amenable to employ it successfully as an electrochemical sensor for the determination of traces of thallium in environmental samples. Measurements carried out on the waters from wells and boreholes in the village of Yamtenga reveal thallium levels above the standard for some sources of water. These waters are therefore not recommended for use as drinking as drinking water.Abstract: This paper describes a procedure for the determination of thallium by differential pulse anodic stripping voltammetry (DPASV) using a mercury film deposited on glassy carbon as the working electrode. The procedure has been optimized using experimental design methodology. The following results were obtained: deposition potential: -1000 mV, depositio...Show More
