Persistence of Bifenthrin in Sandy Loam Soil as Affected by Microbial Community

Soil was fortified with bifenthrin at the level of 10 mu g g(-1) soil. Soil samples were drawn at regular intervals of 0, 10, 20, 30 and 40 days. For extraction of bifenthrin, soil was extracted with acetone. Clean up was done by liquid-liquid partitioning with dichloromethane after diluting with brine solution. Quantification of bifenthrin residues was done by GC using mega bore column and ECD detector. Recovery of bifenthrin in soil ranged between 92.6 % and 93.8 % at 0.5 and 1.0 mu g g(-1). The instrumental limit of detection of bifenthrin was 0.005 mu g mL(-1) and LOQ for soil by this method was found to be 0.05 mu g g(-1). The calibration curve was found to be linear within range the range of 0.01 and 0.10 mu g mL(-1) concentration. The DT50 (disappearance time for 50 % loss) of bifenthrin at the level of 10 mu g g(-1) in sterile and non sterile soil were found to be 330 and 147 days, respectively. A vast difference in the half life of sterile and non sterile soil indicated the presence of potential microbes for bifenthrin degradation.