Analytica Chimica Acta

Autor: Ferreira, Sergio Luis Costa, Ferreira, Hadla S., Jesus, Robson M. de, Santos, João Victor da Silva, Brandão, Geovani Cardoso, Souza, Anderson Santos
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: Repositório Institucional da UFBA
Universidade Federal da Bahia (UFBA)
instacron:UFBA
ISSN: 0003-2670
DOI: 10.1016/j.aca.2007.09.002
Popis: Texto completo: acesso restrito. p. 89-93 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2014-01-13T14:34:20Z No. of bitstreams: 1 1-s2.0-S0003267007014511-main.pdf: 161382 bytes, checksum: 114e3a00bdcfbb8c53a30fb02e3dc700 (MD5) Made available in DSpace on 2014-01-13T14:34:20Z (GMT). No. of bitstreams: 1 1-s2.0-S0003267007014511-main.pdf: 161382 bytes, checksum: 114e3a00bdcfbb8c53a30fb02e3dc700 (MD5) Previous issue date: 2007 In this paper, we proposed a procedure for the determination of iron(II) and total iron in wine samples employing molecular absorption spectrophotometry. The ligand used is 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (Br-PADAP) and the chromogenic reaction in absence or presence of ascorbic acid (reducing agent) allows the determination of iron(II) or total iron, respectively. The optimization step was performed using a multivariate technique (Box Behnken design) involving the factors pH, acid ascorbic concentration and reaction time. The method allows the determination of iron(II) and iron(III) in wine samples, with limits of detection and quantification 0.22 and 0.72 μg L−1, respectively. The precision expressed as relative standard deviation (R.S.D.) was 1.43 and 0.56% (both, n = 11) for content of iron(II) in wine samples of 1.68 and 4.65 mg L−1, and 1.66 and 0.87% (both, n = 11) for content of total iron in wine samples of 1.72 and 5.48 mg L−1. This method was applied for determination of iron(II) and total iron in six different wine samples. In these, the iron(II) content varied from 0.76 to 4.65 mg L−1 and from 1.01 to 5.48 mg L−1 for total iron. The results obtained in the determination of total iron by Br-PADAP method were compared with those that were performed after complete acid digestion in open system and determination of total iron employing FAAS. The method of regression linear was used for comparison of these results and demonstrated that there is no significant difference between the results obtained with these two procedures.
Databáze: OpenAIRE
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