Determination of diquat by flow injection-chemiluminescence.
A simple, economic, sensitive and rapid method for the determination of the pesticide diquat was described. This new method was based on the coupling of flow injection analysis methodology and direct chemiluminescent detection; to the authors' knowledge, this approach had not been used up to now with this pesticide. It was based on its oxidation with ferricyanide in alkaline medium; significant improvements in the analytical signal were achieved by using high temperatures and quinine as sensitiser. Its high throughput (144 h(-1)), together with its low limit of detection (2 ng mL(-1)), achieved without need of preconcentration steps, permitted the reliable quantification of diquat over the linear range of (0.01-0.6) microg mL(-1) in samples from different origins (river, tap, mineral and ground waters), even in the presence of a 40-fold concentration of paraquat, a pesticide commonly present in the commercial formulations of diquat.
López-Paz
J L
JL
Integrated Coastal Management Research Institute, Higher Polytechnic School of Gandía, Polytechnic University of Valencia, Carretera de Nazaret-Oliva s/n, Grao de Gandía, 46730, Gandía, Valencia, Spain. jolopa@qim.upv.es
Catalá-Icardo
M
M
Antón-Garrido
B
B
D004178:Diquat / Q000032:analysis*; D017022:Flow Injection Analysis / Q000379:methods*; D049449:Luminescence
D004178:Diquat