[Determination of Trichlorfon residues in Olives and Olive Oil]

The persistence of the pesticide, trichlorfon and its metabolite Dichlorvos has been studied in fruit and oil of olive in the type of pickling (Abu Satl ) and a type of oily Seed from Palmyra city in Homs province , where trees has been sprayed in two fields in the fruiting period in 6/9/2010 using the commercial formulation (Cekufon 80% S.P) at a dose of 200 g/100 l water . Samples were collected after an hour ,1 ,3 ,7 ,10 ,20 ,25 ,28 day after spraying. The residues of the pesticide and its main metabolite Dichlorvos were estimated. The half-life and the pre-harvest intervals(PHI)were calculated. Results showed that the amount of initial deposit varied according to olive type where they were 4.78 mg/kg for trichlorfon and 0.58 mg/kg for Dichlorvos in the fruit of Abu Satl type while they were 6.43 mg/kg for Dichlorvos in the fruit of seed type However, these residues of the pesticide and its metabolite Dichlorvos, had disappeared during lapse after spraying where residues reached to less than the MRL on olive fruit ( MRL: 0.5 mg/kg ) after the twentieth day of spraying the pesticide and after first and third day for Dichlorvos in type of Abu Satl and the seed type respectively. The values of half life of trichlorfon in Abu Satl type 4.2 days and in the seed type 3.4 days . The results showed that the rate of pesticide presence and its metabolite was higher in the studied fruit types than in oil in all samples collected at all the periods after spraying and that due to high average of solution in oil. As well as, the processes of normal pickling of fruits, led to rapid reduction of the pesticide and its metabolite in the two types fruit in the samples which had been collected in the late periods after spraying as a result of pesticide widespread in the tissues of fruit and the impact of washing processes effecting to release residues. On the contrary, the calcinations pickling processes of olive fruit led to reduce the amount of residues at average 80% in all collected samples at different periods. The residues of dichlorvos were present less than MRL but the reduction rate as a result of calcinations pickling was intermediate at the disposal of these residues and that could be largely due to the decomposition of trichlorfon to dichlorvos in alkali milieu . On the other hand the presence of the pesticide and its metabolite in the resultant oil of the two tested types fruit were low, where the residues amount of the pesticide reached the MRL in the oil (MRL=0.5mg/kg) after the first day for Abu Satl two olive types and the Seed type, the amount of residues of dichlorvos was less than MRL directly after spraying(0.22 mg/kg) of resultant oil of type Abu Satl and on the seventh day (0.12 mg/kg ) of resultant oil of seed type. The effect of pickling processes by the local way and the pickling by trade way (calcinations) in the presence of the residues of the pesticide trichlorfon and its metabolite has been studied at the collection of fruits at different periods after spraying of the