Persistence, dissipation kinetics, and waiting period of ethion on cucumber by gas chromatography-electron capture detector

This study investigated the persistence, half life, dissipation kinetics, and waiting period of ethion on cucumber by gas chromatography-electron capture detector. The residue analysis of ethion on cucumber was carried out by spraying ethion 50EC 500 g a.i. ha(-1) at fruit developing stage followed by another application at 10-day interval and residue were estimated by validated a method on gas chromatography. The sample extraction and clean up was done by modified quick, easy, cheap, effective, rugged, and safe method. The average initial deposits of ethion on cucumber fruit were found to be 0.92 mg/kg, by following two applications at 10-day interval of ethion 50EC at 500 g a.i. ha(-1). Residues of ethion reached below limit of detection 0.05 mg/kg after 15 days at recommended dosage. Therefore a waiting period of 15 day is suggested to reduce the risk before consumption of cucumber fruit samples after following Good Agricultural Practices. These results would be helpful for safe use of ethion on cucumber and to prevent any health problem to consumers. Since the developed method is simple, sensitive, selective and repeatable, it can be extended for ethion based standardisation of herbal formulations containing cucumber and its use in pesticide industries.