Multi-syringe flow injection system for the determination of the scavenging capacity of the diphenylpicrylhydrazyl radical in methanol and ethanolic media

• Tipo: Artigo em Revista Científica Internacional
• Data: 2007

Autores

Luis M Magalhaes (Autor) Outra; Marcela A Segundo (Autor) FFUP; Christophe Siquet (Autor) FEUP; Salette Reis (Autor) FFUP; Jose L F C Lima (Autor) FFUP

Revista

Título: Mikrochimica Acta

Vol. 157 Nº 1

Páginas: 113-118

ISSN: 0026-3672

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 9 Citações

ISI Web of Science

Scopus - 10 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

CORDIS: Ciências da Saúde

Outras Informações

ID Authenticus: P-004-DYC

DOI: 10.1007/s00604-006-0633-7

Resumo (PT): A multi-syringe flow injection system for the determination of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging capacity using methanol or ethanolic solutions as reaction media is presented. A stopped flow approach was implemented in order to monitor the DPPH• consumption using spectrophotometry at 517 nm. The kinetic profile for the first 3 min of reaction was determined for several antioxidant compounds and the number of DPPH• molecules reduced by one molecule of antioxidant was calculated whenever the absorbance value was stable within the period of measurement. For ascorbic acid, trolox, isoeugenol and quercetin in methanol, the values obtained were similar to those reported in the literature. It was possible to perform 14 determinations per hour, consuming 0.34 µmol of DPPH• per determination, which accounts for the application of this system as a screening tool for fast scavenger compounds. <br> <br> Key words: Multi-syringe flow injection; DPPH•; spectrophotometry; solvent and pH effect. <br> <a target="_blank" href="http://web.ebscohost.com/ehost/detail?vid=6&hid=7&sid=a94498a0-e830-4c0b-9153-f61a7e6dfc60%40sessionmgr14&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=a9h&AN=23591292 "> Texto integral </a> <br> <br>

Abstract (EN): A multi-syringe flow injection system for the determination of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH.) scavenging capacity using methanol or ethanolic solutions as reaction media is presented. A stopped flow approach was implemented in order to monitor the DPPH. consumption using spectrophotometry at 517 nm. The kinetic profile for the first 3 min of reaction was determined for several antioxidant compounds and the number of DPPH. molecules reduced by one molecule of antioxidant was calculated whenever the absorbance value was stable within the period of measurement. For ascorbic acid, trolox, isoeugenol and quercetin in methanol, the values obtained were similar to those reported in the literature. It was possible to perform 14 determinations per hour, consuming 0.34 mu mol of DPPH. per determination, which accounts for the application of this system as a screening tool for fast scavenger compounds.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6