Residual Degradation Dynamics of Malathion in Cucumber

A gas chromatographic (GC with FPD) method for the determination of malathion in cucumber was developed. Malathion in cucumber was extracted by acetonitrile, the residue was redissolved with acetone, and malathion was quantified by external standard method. The result showed that the limit of detection was 0.002 ng,the recoveries were 93.6% to 111.7% when the added levels were from 0.002 to 0.100mg/kg, the RSD was 2.8% to 20.8%. Malathion degraded rapidly and the half-life of malathion in cucumber was 0.35 day, the residue of malathion was lower than the limit of detection three days later.