Shahrzad Mohammadi - M.Sc student of Entomology, Faculty of Agriculture, Islamic Azad University, Science and Research Branch, Tehran, Iran
Sohrab Imani - Assistant professor of Department of Entomology Faculty of Agriculture, Islamic Azad University, Science and Research Branch, Tehran, Iran.

As farmers use different pesticides several times for tomato's pest control. It causes that their residue be arisk factor for human's health. In considering the important of tomato from an economic view, this studywas conducted on this product to measure post harvest period (php) of two Chlorpyrifos and deltametherinpesticides. Tomato samples cultivated in 2 greenhouses with the design pattern of randomized completeblock with 3 replicates. Every treatment sprayed with studied insecticides 2 times. For deltametherin withinone hour and 1, 2,3,4,5,7,10,15 days after spraying and for Chlorpyrifos within one hour and1,3,5,7,10,15,20,30 days after spraying sampling was performed . Samples in laboratory were extracted byusing SPE(Solid Phase Extraction) and with the help of N method were concentrated and extracts wereinjected for measurement into HPLC(High Performance Liquid Chromatograph),GC(GasChromatograph),GC/MS(GC/Mass Spectrometer) devices. Data were compared with WHO/FAO andnational MRL and Recovery results were 101% and 94% for Chlorpyrifos and deltametherin as respectivelyalso results showed that deltametherin has the php about 3 days and Chlorpyrifos has the php near 15 days ingreenhouse condition has been studied. However, toget the post harvest period under farm condition more studies are needed.

post harvest period, insecticide residue,MRL, randomized complete block