Analysis of organophosphorus, organochlorine and pyrethroid insecticides in medicinal plants

Multiresidue analysis of organophosphorus, organochlorine and pyrethroid pesticides in medicinal plants, gives problems of extraction, purification and detection. Analytical methodologies have been developed for vervain and tested for camomile and peppermint without prior knowledge of the pesticides used in their treatment. Extraction is common to all three pesticide families: acetone or acetonitrile is chosen depending on the particular matrix. Isolation of organophosphorus compounds is performed by gel permeation chromatography. Organochlorine and pyrethroid pesticides are extracted in two steps: gel permeation followed by adsorption chromatography on silica gel cartridges. Analysis and detection of organophosphorus compounds is by gas chromatography with a nitrogen phosphorus detector; organochlorine and pyrethroid compounds are identified by gas chromatography with an electron capture detector.