Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/53188
Type: Artigo de periódico
Title: A flow-injection spectrophotometric method for nitrate and nitrite,determination through nitric oxide generation
Author: Andrade, R
Viana, CO
Guadagnin, SG
Reyes, FGR
Rath, S
Abstract: A flow injection method with novel spectrophotometric detection for the determination of nitrite and nitrate in foodstuffs is presented. The method is based on the reduction of nitrite and nitrate to nitric oxide, with subsequent reaction with iron (11) and thiocyanate in an acid medium, forming FeSCNNO+. The absorbance of the complex, with a maximum at 460 nm, is proportional to the nitrite and nitrate concentrations. The NO is generated in two stages: (1) reduction of nitrate to nitrite in a cadmium copper reductor column and (2) reduction of the nitrite to NO in a sulfuric acid medium. The influence of reagent concentrations and manifold parameters were evaluated. Nitrite and nitrate can be determined in the range of 0.30-3.00 and 1.00-10.00 mg l(-1), respectively. The sampling rate of analyses was 30-40 h(-1) and, considering a sample of 5.0 g, the determination limit of the method was 20 and 13 mg kg(-1) of nitrate and nitrite, respectively. Nitrite and nitrate were determined in vegetables and meat products by the proposed method. The precision and accuracy of the proposed method were comparable to those of the reference spectrophotometric method (official AOAC reference method for the determination of nitrate in foodstuffs). (C) 2002 Elsevier Science Ltd. All rights reserved.
Subject: nitrite
nitrate
meat products
vegetables
FI analysis
Country: Inglaterra
Editor: Elsevier Sci Ltd
Rights: fechado
Identifier DOI: 10.1016/S0308-8146(02)00508-3
Date Issue: 2003
Appears in Collections:Unicamp - Artigos e Outros Documentos

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