Persistence of Cypermethrin and Acephate in Acidic, Neutral and Alkaline Water

Persistence of cypermethrin and acephate was studied in acidic, neutral and alkaline water after spiking each type of water at 1, 2 and 4 mg kg^-1. Water samples were analysed by following standardized analytical methodology and estimated residues of cypermethrin and acephate by employing electron capture detector and fame thermionic detector (FTD) on a gas chromatograph using a capillary column. The results revealed faster degradation of cypermethrin as compared to acephate. Cypermethrin residues in acidic, neutral and alkaline waters degraded below its determination limit of 0.01 mg kg^-1 after 15 days when spiked at 1 mg kg^-1. Acephate residues declined below its determination limit of 0.01 mg kg^-1 after 30 days of spiking at 1, 2 and 4 mg kg^-1. Methamidophos, metabolite of acephate was not detected in acidic, neutral or alkaline water at the highest spiking level of 4 mg kg^-1.