Determination of polyphenols in wines by reaction with 4-aminoantipyrine and photometric flow-injection analysis
| Autor: | M. Goreti F. Sales, Jan W Schoonen |
|---|---|
| Přispěvatelé: | Repositório Científico do Instituto Politécnico do Porto |
| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: |
Total polyphenols
Polymers Analytical chemistry Wine Biochemistry Analytical Chemistry Photometry chemistry.chemical_compound Phenols Spectrophotometry Oxidizing agent medicine Flow injection and FIA Flow injection analysis Flavonoids Chromatography medicine.diagnostic_test Color reaction food and beverages Polyphenols Reproducibility of Results Wines Ampyrone chemistry Polyphenol Reagent Flow Injection Analysis |
| Zdroj: | Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP |
| Popis: | A new flow-injection analytical procedure is proposed for the determination of the total amount of polyphenols in wines; the method is based on the formation of a colored complex between 4-aminoantipyrine and phenols, in the presence of an oxidizing reagent. The oxidizing agents hexacyanoferrate(III), peroxodisulfate, and tetroxoiodate(VII) were tested. Batch trials were first performed to select appropriate oxidizing agents, pH, and concentration ratios of reagents, on the basis of their effect on the stability of the colored complex. Conditions selected as a result of these trials were implemented in a flow-injection analytical system in which the influence of injection volume, flow rate, and reaction- coil length, was evaluated. Under the optimum conditions the total amount of polyphenols, expressed as gallic acid, could be determined within a concentration range of 36 to 544 mg L–1, and with a sensitivity of 344 L mol–1 cm–1 and an RSD |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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