A novel electrochemical analysis of the legal psychoactive drug caffeine using a zeolite/MWCNT modified carbon paste sensor
| Autor: | Mohamed R. Shehata, Amany M. Fekry, Shereen M. Azab |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Detection limit
Scanning electron microscope 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Catalysis 0104 chemical sciences Dielectric spectroscopy chemistry.chemical_compound chemistry Electrode Materials Chemistry Sodium dodecyl sulfate Cyclic voltammetry 0210 nano-technology Caffeine Nuclear chemistry |
| Zdroj: | New Journal of Chemistry. 43:15359-15367 |
| ISSN: | 1369-9261 1144-0546 |
| DOI: | 10.1039/c9nj04070f |
| Popis: | Caffeine (Caf) is a natural central nervous system stimulant categorized by the US Food and Drug Administration as a safe drug and its maximal amount in soft drinks has been approximately determined to be lower than 200 mg L−1. It is the world's most extensively used legal and unregulated psychoactive medication. A simple, low cost, sensitive and selective electrochemical method for the detection of Caf was developed using zeolite (Zeo) mixed with multi-walled carbon nanotube (MWCNTs) to give a modified carbon paste electrode (CPE) in a surfactant improved medium with sodium dodecyl sulfate (ZMWCNTMCPE/SDS) and carrying out cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) measurements. Scanning electron microscopy (SEM) was also used to characterize the surface. The influence of varying the concentration versus the anodic current of Caf gives two linear ranges, the first is from 1.0 × 10−5 to 1.0 × 10−4 mol L−1, with a correlation coefficient of 0.9878, and the second is from 1.0 × 10−4 to 5.0 × 10−4 mol L−1. The limits of detection and quantitation were found to be 7.5 × 10−8 and 2.5 × 10−7 mol L−1 respectively. The results show that the new sensor can be used to quantify Caf in black tea, coffee, Nescafe, Pepsi cola, diluted energetic drink samples, in real samples and Panadol extra pharmaceutical tablets. Satisfactory recoveries for all of the samples were obtained between 99.51% and 102.19% with relative standard deviations of 1.7–5.1%. |
| Databáze: | OpenAIRE |
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