Enantiomeric separation of organophosphorus pesticides by capillary electrophoresis. Application to the determination of malathion in water samples after preconcentration by off-line solid-phase extraction

The separation of the enantiomers of a group of organophosphorus pesticides (OPs) has been investigated by electrokinetic chromatography (EKC) using different anionic cyclodextrins as chiral selectors. The use of a 25 mM Tris buffer (pH 7.0), 20 mM in CM-β-CD together with an applied voltage of 24 k...

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Detalles Bibliográficos
Autores: García Ruiz, Carmen|||0000-0001-5925-3449, Álvarez Llamas, Gloria, Puerta, Ángel, Blanco, Elisa, Sanz Medel, Alfredo, Marina Alegre, María Luisa|||0000-0002-5583-1624
Tipo de recurso: artículo
Fecha de publicación:2005
País:España
Institución:Universidad de Alcalá (UAH)
Repositorio:e_Buah Biblioteca Digital Universidad de Alcalá
Idioma:inglés
OAI Identifier:oai:ebuah.uah.es:10017/1351
Acceso en línea:http://hdl.handle.net/10017/1351
https://dx.doi.org/10.1016/j.aca.2005.04.027
Access Level:acceso abierto
Palabra clave:Enantiomeric separation
Organophosphorus pesticides
Capillary electrophoresis
Malathion
Solid-phase extraction
Ciencia
Química analítica e industrial
Science
Chemistry, analytic and technical
Descripción
Sumario:The separation of the enantiomers of a group of organophosphorus pesticides (OPs) has been investigated by electrokinetic chromatography (EKC) using different anionic cyclodextrins as chiral selectors. The use of a 25 mM Tris buffer (pH 7.0), 20 mM in CM-β-CD together with an applied voltage of 24 kV and a temperature of 25 °C enabled the individual enantiomeric separation of malathion and phenthoate each one into its two enantiomers, the partial separation of the enantiomers of phenamiphos and the separation of three of the four enantiomers of isomalathion. Since naled is very reactive in aqueous solutions, its enantiomeric separation achieved in about 8 min in 25 mM borate buffer at pH 9 with 10 mM CM-β-CD resulted in the observation of a broad peak due to degradation products. A preconcentration step by disk solid-phase extraction was studied and used together with the chiral EKC method developed for the enantiomeric separation of malathion in order to determine this pesticide in tap water samples spiked at the μg mL−1 level. Finally, the precision and recovery of the method was established.