| Abstract: | Organophosphorous pesticides were analyzed based on the inhibition of acetylcholinesterase (AChE) from housefly and the electric eel using a sequential injection analysis (SIA) system. This analytical system is fully computerized and is able to automatically monitor the pesticide residues in an assay cycle of 180 s including 30 s incubation time when the flow is stopped. The optimal operation conditions such as AChE, substrate, pH, flow rate, and stopping time were studied. The experimental setup gave good reproducibility with the linear ranges for paraoxon of 1–70 ppb and dichlorovos of 20–70 ppb. The detection limits of paraoxon and dichlorovos were 1 and 5 ppb, respectively. The AChE from housefly shows 10 times higher sensitivity than the enzyme from the eel for these pesticide determination in this system. |
