Study of the Degradation of Carbofuran using Response Surface Methodology

CarbofuranhasbeenbannedbytheEuropeanUnionin1999,however,thisinsecticide continues to be widely used in Asia, Australia and South America, including Malaysia. The degradation of carbofuran under the effects of pH (4-7), moisture (30 -70%) andtemperature (30 –70ºC) were studied using response surface methodology. Sterilized soil was incubated according to the inscribed central composite design with a total of 24 experiments. The percentage of carbofuran loss was calculated and fitted according to linear, interaction and quadraticmodels.Themodelqualitywasmeasuredbasedontherootmeansquareerror(RMSE)and regression coefficient, R2. Linear model was the best model to describe the degradation of carbofuranwiththelowestRMSE.Allthethreefactorswerefoundtocorrelatepositivelytothe loss of carbofuran with pH demonstrating a significant effect (p < 0.05). This suggests that hydrolysis is the major pathway controlling the degradation of carbofuran. The model was experimentally verified revealing an error of5.82%.