This study was conducted to measure post harvest period (php) of Chlorpyrifos . Tomato samples cultivated in 2 greenhouses with the design pattern of randomized complete block with 3 replicates. Every treatment sprayed with studied insecticide 2 times. Within different days after spraying sampling was performed. Samples in laboratory were extracted by using SPE(Solid Phase Extraction) and with the help of N method were concentrated and extracts were injected for measurement into GC(Gas Chromatograph),GC/MS(GC/Mass Spectrometer) devices. Data were compared with WHO/FAO MRL and Recovery results were 101% also results showed that Chlorpyrifos has the post harvest period near 15 days in greenhouse condition has been studied.
