Flow-injection electrochemical determination of citric acid using a cobalt(II)-phthalocyanine modified carbon paste electrode

TALANTA

卷:105

Article

do Nascimento, Raphael Fonseca¹  Guimaraes Selva, Thiago Matheus^2,3  Ribeiro, Williame Farias⁴  Belian, Monica Freire⁵  Angnes, Lucio⁶  do Nascimento, Valberes Bernardo¹ 

[1] Univ Fed Rural Pernambuco, Dept Quim, BR-52171030 Recife, PE, Brazil

[2] Univ Fed Pernambuco, CCEN, Dept Quim Fundamental, BR-50670901 Recife, PE, Brazil

[3] Inst Fed Educ Ciencia & Tecnol Pernambuco, BR-50740540 Recife, PE, Brazil

[4] Univ Fed Paraiba, CCEN, Dept Quim, BR-58051970 Joao Pessoa, PB, Brazil

[5] Univ Fed Rural Pernambuco, Dept Ciencias Mol, BR-52171030 Recife, PE, Brazil

[6] Univ Sao Paulo, Inst Quim, Sao Paulo, Brazil

关键词: Citric acid;    Cobalt(II)-phthalocyanine;    Carbon paste electrode;    Flow injection analysis;    Amperometry;    Square wave voltammetry;    Fruit juices;   

DOI  :  10.1016/j.talanta.2012.10.055

来源: Elsevier

【 摘 要 】

The electrocatalytic activity of cobalt(II)-phthalocyanine immobilized in a carbon paste electrode for citric acid oxidation under a diffusion-controlled electrochemical process was employed to develop a selective flow injection amperomettric analysis method. Under optimized conditions, rapid and reliable determinations of citric acid (65 samples per hour) were achieved for analyses of commercial fruit juices with minor pretreatment of the samples. A linear response was accomplished ranging from 0.25 to 15 mmol L-1 (r(2)=0.9979) with an estimated detection limit of 0.117 mmol L-1. Alternatively, a very sensitive and selective assay was developed for the micromolar range, obtaining a linear response ranging from 3.81 to 91.2 mu mol L-1 (r(2)=0.9993) with an estimated detection limit of 2.54 mu mol L-1, by using square wave voltammetric methodology. The speed and simplicity of the proposed approaches compares advantageously to the all other citric acid determination methods. (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

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