Publication
FIA potentiometric system based on periodate polymeric membrane sensors for the assessment of ascorbic acid in commercial drinks
| dc.contributor.author | Guerreiro, J. Rafaela L. | |
| dc.contributor.author | Kamel, Ayman H. | |
| dc.contributor.author | Sales, M. Goreti F. | |
| dc.date.accessioned | 2013-11-29T15:29:04Z | |
| dc.date.available | 2013-11-29T15:29:04Z | |
| dc.date.issued | 2010 | |
| dc.description.abstract | Ascorbic acid is found in many food samples. Its clinical and technological importance demands an easyto- use, rapid, robust and inexpensive method of analysis. For this purpose, this work proposes a new flow procedure based on the oxidation of ascorbic acid by periodate. A new potentiometric periodate sensor was constructed to monitor this reaction. The selective membranes were of PVC with porphyrin-based sensing systems and a lipophilic cation as additive. The sensor displayed a near-Nernstian response for periodate over 1.0x10-2–6.0x10-6 M, with an anionic slope of 73.9 ± 0.9 mV decade-1. It was pH independent in acidic media and presented good selectivity features towards several inorganic anions. The flow set-up operated in double-channel, carrying a 5.0x10-4 M IO- 4 solution and a suitable buffer; these were mixed in a 50-cm reaction coil. The overall flow rate was 7 ml min-1 and the injection volume 70 µl. Under these conditions, a linear behaviour against concentration was observed for 17.7–194.0 µg ml-1, presenting slopes of 0.169 mV (mg/l)-1, a reproducibility of ±1.1 mV (n = 5), and a sampling rate of ~96 samples h-1. The proposed method was applied to the analysis of beverages and pharmaceuticals. | por |
| dc.identifier.doi | 10.1016/j.foodchem.2009.11.015 | pt_PT |
| dc.identifier.issn | 0308-8146 | |
| dc.identifier.uri | http://hdl.handle.net/10400.22/3040 | |
| dc.language.iso | eng | por |
| dc.peerreviewed | yes | por |
| dc.publisher | Elsevier | por |
| dc.relation.ispartofseries | Food Chemistry; Vol. 120, Issue 3 | |
| dc.relation.publisherversion | http://www.sciencedirect.com/science/article/pii/S0308814609013077 | por |
| dc.subject | Periodate | por |
| dc.subject | Ascorbic acid | por |
| dc.subject | Potentiometric sensors | por |
| dc.subject | Flow injection analysis (FIA) | por |
| dc.subject | Flavoured waters | por |
| dc.title | FIA potentiometric system based on periodate polymeric membrane sensors for the assessment of ascorbic acid in commercial drinks | por |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| oaire.citation.endPage | 939 | por |
| oaire.citation.startPage | 934 | por |
| oaire.citation.title | Food Chemistry | por |
| oaire.citation.volume | 120 | por |
| rcaap.rights | closedAccess | por |
| rcaap.type | article | por |