Degradation products of lambda-cyhalothrin in aqueous solution as determined by SBSE-GC-IT-MS

Abstract

Lambda-cyhalothrin is a widely employed pyrethroid insecticide and is potentially toxic to the environment and to human health. Several reports indicate the presence of this insecticide in water samples worldwide, but more data about its behavior in waters and its derivative products are required. This study shows the behavior of the pesticide lambda-cyhalothrin in aqueous solution at different pH and temperature that were simulated by using water contaminated with a toxic concentration of lambda-cyhalothrin and chemical oxidative process. Lambda-cyhalothrin and its derivative products were monitored employing stir bar sorptive extraction (SBSE), using liquid and thermal desorption, combined with gas chromatography coupled with ion trap mass spectrometry (GC-IT-MS) technology. GC-IT-MS enabled the proposal of the lambda-cyhalothrin chemical transformation pathway and the full identification of twelve derivative products. Among them, only 3-phenoxybenzaldehyde is reported as a degradation product of lambda-cyhalothrin, and this compound is an environmental pollutant with endocrine disrupting activity.