DISAPPEARANCE OF PENDIMETHALIN IN SOIL AND ITS RESIDUE IN RIPE FENNEL
2009, 10 (2) p. 153-158
Disappearance of pendimethalin in soil, a herbicide widely used for control of weeds on vegetable crops, has been studied. A simple and rapid multiresidue analytical procedure for the quantifi cation of the substance has been applied using a Hewlett Packard 5890A gas chromatograph, equipped with a nitrogen – phosphorus detector (GC-NPD). Disappearance trend followed fi rst order kinetics seemed to be the best approximation. The average pendimethalin residues have decreased according to equations: y = 0.236e-0.0115x (exponential) and y = -0.0018x + 0.226 (linear) with excellent coeffi cient of determination in both cases. Half-lives obtained from those equations were 60 and 62 days, respectively. Low pendimethalin residue in plants indicate that fresh fennel may be used as additive in baby food. On the other hand, the experimental results indicate that pendimethalin is quite stable compound and may cause problems with follow-up crops.