DETECTION OF CARBAMATE PESTICIDES IN VEGETABLE SAMPLES USING CHOLINESTERASE-BASED BIOSENSORS

Biosensors for determination of carbamates in vegetables based on five different cholinesterases as biorecognition elements and a screen-pri nted electrode system as an amperometric transducer were developed. Me asurements were simply performed by dropping solutions (either sample or substrate) directly on the biosensor. The response of biosensors to selected carbamates (aldicarb, carbaryl, carbofuran, methomyl and pro poxur) was characterized. The performance was evaluated on extracts of potatoes and carrots, the results from the AChE biosensor and a stand ard HPLC procedure were compared. Finally, the biosensor was used for the direct analysis of vegetable juices without any pretreatment steps . In this case, 10 mu g/L levels of added carbofuran and propoxur were reliably identified. The whole procedure takes less than 20 min inclu ding 10 min incubation with samples. The concentrations of carbamates determined with biosensor agreed well for carbofuran. Lower response w as observed for propoxur.