Extraction-free colorimetric determination of thymol and carvacrol isomers in essential oils by pH-dependent formation of gold nanoparticles
| Autor: | Alberto Escarpa, Fabiana D’Eramo, Juan M. Marioli, Agustín G. Crevillén, Natalia Verónica Tonello |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
SURFACE PLASMON RESONANCE
Nanoparticle 01 natural sciences OREGANO Analytical Chemistry chemistry.chemical_compound 0404 agricultural biotechnology Carvacrol Phenols Thymol Detection limit Chromatography 010401 analytical chemistry Extraction (chemistry) Ciencias Químicas 04 agricultural and veterinary sciences FOLIN-CIOCALTEU 040401 food science 0104 chemical sciences chemistry Colloidal gold GOLD NANOPARTICLES CYCLIC VOLTAMMETRY Química Analítica Absorption (chemistry) THYME CIENCIAS NATURALES Y EXACTAS |
| DOI: | 10.1007/s00604-018-2893-4 |
| Popis: | An extraction-free method is described for the colorimetric determination of thymol (TY) and carvacrol (CA) isomers in essential oils by making use of the pH-dependent formation of gold nanoparticles (AuNPs). In solutions of pH 12, TY and CA form gold nanoparticles, while at pH ≤ 11 only CA does so. By taking advantage of this finding, two different approaches based on colorimetric assay (absorption at 550 nm) were developed: one at pH 12 for the determination of total CA and TY, and other at pH 9 and pH 12 for differential quantification of TY and CA. The former agrees with the well-established Folin-Ciocalteu method, and the latter provides a simple way for calculation of TY/CA ratio. The linear ranges are from 100 to 1000 μM at pH 9, and from 50 to 200 μM at pH 12. The limits of detection are 0.09 μM at pH 9, and 0.02 μM at pH 12. These features make this method simple, fast and reliable. Conceivably, it can be used to assess the quality of essential oils and may become a valuable alternative to more sophisticated, laborious and high time-consuming methods. Fil: Tonello, Natalia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Universidad de Alcalá; España Fil: D'eramo, Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina Fil: Marioli, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina Fil: Crevillen, Agustín G.. Universidad Nacional de Educación a Distancia; España Fil: Escarpa, Alberto. Universidad de Alcalá; España |
| Databáze: | OpenAIRE |
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