Determination of the Fungicide Anilazine in Soil and River Water by Differential Pulse Polarography

The electrochemical behavior of anilazine (4,6-dichloro-N-(2-chlorophenyl)-1,3,5-triazin-2-amine) fungicide has been studied at a dropping mercury electrode. The differential pulse polarographic technique was used to establish an electroanalytical procedure for the determination of the anilazine levels in natural water and soil samples. Three reduction peaks were observed as a function of pH. The polarographic reduction that exhibited only a single well-defined peak in the pH range from 1.0 to 5.0, was chosen for the analytical determination. The variation of pH and polarographic parameters indicated that the optimum conditions under which anilazine could be reduced were pH = 2.0, Britton-Robinson (B-R) buffer solution, a reduction peak potential of -795 mV (vs. SCE), scan rate of 5 mV s(-1), pulse amplitude of -50 mV with a pulse duration of 50 iris at an ambient temperature of 20 +/- 3 degrees C. A linear relationship between the first peak height and the concentration of anilazine was obtained in the range of 0.497 to 64.800 mu M, with a detection limit of 0.128 mu M. The mean recoveries of the 10.0 mu M anilazine spiked to soil and river water were 9.8 +/- 0.1 and 9.6 +/- 0.5 mu M at the 95% confidence level, respectively. The sufficiently good recoveries and low relative standard deviation (RSD) data reflects the high accuracy and precision of the proposed pulse polarographic method. The interferences with the reduction peak of anilazine peak observed with several commonly used pesticides and inorganic species were also tested. Some interfering species were eliminated either by providing selectivity with pH changes or using complexing agents, e.g., EDTA.