title: Voltammetric determination of linuron at a carbon-paste electrode modified with sepiolite.
abstract: The determination of linuron by differential pulse voltammetry with a carbon-paste electrode modified with 20% w/w sepiolite has been studied. The linuron is preconcentrated under open-circuit conditions at pH 2.0. With 0.01M potassium nitrate at pH 1.7 in the measurement cell, a sweep rate of 30 mV/sec and a pulse amplitude of 100 mV, an oxidation wave with a peak potential of 1.2 V is obtained. Under these conditions, determination limits of 75 ng/ml have been obtained, with a relative error of +2.8% and a relative standard deviation of 8.0%. The method has been applied to the direct determination of linuron in river water with no previous separation of the pesticide. Determination in sea-water is not possible, as chloride interferes at high concentration.
authors.affiliation: Departamento de Química, Universidad Autónoma de Madrid, Madrid 28049, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Hernandez
authors.forename: J
authors.initials: J
authors.lastname: Vicente
authors.forename: M
authors.initials: M
authors.lastname: Gonzalez
authors.forename: L
authors.initials: L
authors.lastname: Hernandez