Electroanalytical determination of the herbicide paraquat in natural water and commercial tea samples with gold electrodes obtained from recordable compact disc

This work describes the application of gold electrodes constructed from recordable compact discs for the analytical determination of the herbicide paraquat in natural water samples using square wave voltammetry. The detection limit for pure water (laboratory samples) was 21 mug L-1, lower than the EPA limit for drinking water (100 mug L-1). The experimental quantification limit was determined as 73 mug L-l. In polluted creek water samples the detection limit rose to 76.4 mug L-1 and is shown to be dependent on BOD and COD values. Recovery measurements in tea and natural water samples were approximately 95%, which indicates that the methodology can be employed to analyze paraquat in such matrices.