GC-MS DETERMINATION OF ORGANOCHLORINE PESTICIDES IN 5 MEDICINAL-PLANTS

Capilllary gas chromatography-mass spectrometry (GC-MS) in the electron impact (EI) mode and using selected ion monitoring (SIM) has been used to determine the main organochlorine pesticides in five commonly used medicinal plants (mint, vervain, camomile, lime tree and tea). Solid-phase extraction (SPE) is proposed for the treatment of these medicinal herbs. Validation of this step using factorial discriminant analysis (FDA) has shown that these plants can not be considered as one homogeneous group with regard to the extraction procedure. Consequently, two procedures have been designed. In each procedure, the plant is infused prior to SPE. Elution is achieved with n-hexane-dichloromethane (85:15, v/v). If necessary, the organic extract is treated with trifluoroacetic acid (TFA) to reduce matrix interferences.