Electrochemical quantification of chlorpyrifos in white (Allium cepa L.) and green (Allium fistulosum L.) onions

José Mauricio  García Colmenares; Leidy Paola  Páez Cepeda; Sandra Patricia  Chaparro Acuña

Electrochemical quantification of chlorpyrifos in white (Allium cepa L.) and green (Allium fistulosum L.) onions

Autores

José Mauricio García Colmenares

Leidy Paola Páez Cepeda

Sandra Patricia Chaparro Acuña

Editor

Universidad Nacional de Colombia

Descripción

The Linear sweep voltammetry method (LSP) of a common pesticide such as chlorpyrifos (CP) an organophosphate pesticide (OPP) in white (Allium cepa L.) and green onions (Allium fistulosum L.) was investigated. A hanging mercury drop electrode (HMDE) Ag/AgCl was used as reference electrode and platinum as a counter electrode. The OPP was extracted from the onion through liquid-liquid partition using acetone/dichloromethane as the solvent. Validated method was compared with GC/ECD as a reference method. CP concentration was not different between the two analytical techniques; the analysis was performed with a confidence level of 90%, corresponding to the polarographic method. CP concentration was 0.8400 ± 0.062 ppm in Allium cepa and 0.062 ± 0.300 ppm in Allium fistulosum L. These values exceed the ADI and ARD values for chlorpyrifos established by current regulations.