| Autor: |
Diniz JA; Departamento de Química, Universidade Federal de Viçosa, Av. Peter Henry Holfs, Viçosa, 3650-900, MG, Brazil. julianaapdiniz@hotmail.com., Okumura LL; Departamento de Química, Universidade Federal de Viçosa, Av. Peter Henry Holfs, Viçosa, 3650-900, MG, Brazil. julianaapdiniz@hotmail.com., Filomena de Souza Silva A; Departamento de Química, Universidade Federal de Viçosa, Av. Peter Henry Holfs, Viçosa, 3650-900, MG, Brazil. julianaapdiniz@hotmail.com., Oliveira AF; Departamento de Química, Universidade Federal de Viçosa, Av. Peter Henry Holfs, Viçosa, 3650-900, MG, Brazil. julianaapdiniz@hotmail.com., Gurgel A; Departamento de Química, Universidade Federal de Viçosa, Av. Peter Henry Holfs, Viçosa, 3650-900, MG, Brazil. julianaapdiniz@hotmail.com., Liberato PA; Departamento de Química, Universidade Federal de Viçosa, Av. Peter Henry Holfs, Viçosa, 3650-900, MG, Brazil. julianaapdiniz@hotmail.com., Aleixo H; Instituto Federal do Espírito Santo, Rodovia ES 320, Km 118, Zona Rural, Três Vendas, Barra de São Francisco, 29800-000, ES, Brazil., Silva JG; Departamento de Química, Universidade Federal de Minas Gerais, Av. Antônio Carlos, Belo Horizonte, 31270-901, MG, Brazil. |
| Abstrakt: |
A novel voltammetric screening method has been developed for the rapid determination of fipronil (FPN) residues in lactose-free milk samples with the use of a carbon-paste electrode (CPE) by differential-pulse voltammetry (DPV). Cyclic voltammetry indicated the occurrence of an irreversible anodic process at approximately +0.700 V ( vs. Ag|AgCl, 3.0 mol L -1 KCl) in a 0.100 mol L -1 NaOH supporting electrolyte prepared as a 30% (v/v) ethanol-water solution. Quantification of FPN was carried out by DPV and analytical curves were constructed. In the absence of a matrix, the limits of detection (LOD) and quantification (LOQ) were 0.568 mg L -1 and 1.89 mg L -1 , respectively. In the presence of a lactose-free skim milk matrix, the values of LOD and LOQ were 0.331 mg L -1 and 1.10 mg L -1 . The recovery percentages for three different concentrations of FPN in lactose-free skim milk samples ranged between 95.3% and 109%. All assays could be conducted with milk samples without any prior extraction steps or pre-concentration of FPN, making this novel method rapid, simple, and relatively cheap. |
