Dissipation and leaching studies of cyazofamid in two texturally different soils of Tarai region of India at two fortification levels (100 and 200 g a.i. ha -1 ) were carried out for monitoring residual toxicity and groundwater contamination. Soil was extracted with acetone : methanol (5:1 v/v) followed by cleanup with florisil SPE. Separation was achieved by RP-HPLC on a Discovery Ò C-18 column using mobile phase acetonitrile: water (60:40 v/v) and detection at 279 nm. Degradation pattern indicated correspondence to monophasic first-order kinetics in soils with half-life values ranging from 4.3 to 4.95 days. The degradation rate was slight different in both types of soils. Persistence was higher in sandy loam compared to silty clay loam soil. Linearity, R 2 of calibration curve, instrument limit of detection/quantitation (LOD/LOQ) was evaluated. Good linearity (R 2 = 0.99) of the calibration curves for quantification was obtained over the dynamic range of 0.1-10.0 lg mL -1 , and percent relative standard deviation was 1.72 %. Leaching experiment showed that cyazofamid could not leached beyond 15 cm of soil depth. Maximum concentration was at 5-10 and 10-15 cm soil depth. Average recoveries from soils fortified at 0.5-5.0 lg g -1 ranged from 78 to 86 %. Instrument LOD values were 0.01 lg mL -1 , and method LOQ values were 0.05 lg g -1 . A fast, easy and efficient method with acceptable performance was achieved. Results showed that cyazofamid has a short life in soils and low potential to leach down under heavy rainfall conditions. Results confirm that cyazofamid would not build up in the environment and have less possibility of groundwater contamination.
