Continuous-flow/stopped-flow system for determination of ascorbic acid using an enzymatic rotating bioreactor

German A Messina, Angel Alberto Jesus Torriero, Irma E De Vito, Julio Raba

Research output: Contribution to journalArticleResearchpeer-review

21 Citations (Scopus)


The high sensitivity that can be attained using an enzymic system and mediated by hydroquinone, has been verified by online interfacing of a rotating bioreactor and continuous flow/stopped-flow/continuous-flow processing. Horseradish peroxidase, HRP, [EC], immobilized on a rotating disk, in presence of hydrogen peroxide catalyzes the oxidn. of hydroquinone to p-benzoquinone, whose electrochem. redn. back to hydroquinone is detected on glassy carbon electrode (GCE) surface at -0.15 V. Thus, when L-ascorbic acid is added to the soln., this acid is reduced chem. (p-benzoquinone to hydroquinone) and acts as mediator of HRP, decreasing the peak current obtained proportionally to the increase of its concn. The recovery of l-ascorbic acid from four samples ranged from 99.09 to 101.10 . This method could be used to det. l-ascorbic acid concn. in the range 12 nM-3.5 micro M (r = 0.998). The detn. of l-ascorbic acid was possible with a limit of detection of 6 nM in the processing of as many as 25 samples h-1. The method was successfully applied for the anal. of l-ascorbic acid in pharmaceutical formulations. [on SciFinder (R)]
Original languageEnglish
Pages (from-to)1009 - 1017
Number of pages9
Issue number4
Publication statusPublished - 2004
Externally publishedYes

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