Direct Electrochemical Determination of Glyphosate at Copper Phthalocyanine/Multiwalled Carbon Nanotube Film Electrodes

A copper phthalocyanine/multiwalled carbon nanotube film-modified glassy carbon electrode has been used for the determination of the herbicide glyphosate (Gly) at -50 mV vs. SCE by electrochemical oxidation using differential pulse voltamtnetry (DPV). Cyclic voltammetry and electrochemical impedance spectroscopy showed that Gly is adsorbed on the metallic centre of the copper phthalocyanine molecule, with formation of Gly-copper ion complexes. An analytical method was developed using DPV in pH 7.4 phosphate buffer solution, without any pretreatment steps: Gly was determined in the concentration range of 0.83-9.90 mu mol L(-1), with detection limit 12.2 nmol L(-1) (2.02 mu g L(-1))

CNPq, Brazil[201494/2008-6]

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fundação para a Ciência e a Tecnologia de Portugal (FCT)

Fundacao para a Ciencia e Tecnologia (FCT), Portugal[PTDC/QUI/65255/2006]

Fundacao para a Ciencia e Tecnologia (FCT), Portugal[PTDC/QUI/65732/2006]

Fundação para a Ciência e a Tecnologia de Portugal (FCT)