Fate of fipronil and its metabolites in/on grape leaves, berries and soil under semi arid tropical climatic conditions.

Fate of fipronil and its major metabolites fipronil sulfide (MB 45950), fipronil-desulfinyl (MB 46513) and fipronil sulfone (MB 46136) were studied in/on grape leaves, berries and soil. As initial residue deposits on the leaves the major component was that of fipronil, while all the 3 metabolites were also present. Among metabolites residues of MB 46513 was highest followed by MB 46136 and MB 45950. In leaves fipronil degraded faster than its metabolites. The residues of fipronil in leaves degraded at the half-life of 9.6 and 18.3 days and that of total fipronil (sum of fipronil and its metabolites) at 13.6 and 20 days, from treatment at recommended and double the recommended dose, respectively. At the time of harvest in leaves, grape berries and soil residues of fipronil and all its metabolites were below the quantifiable limit of 0.01 mg kg(-1).