Molecular recognition in a propazine-imprinted polymer and its applicationto the determination of triazines in environmental samples

An analytical methodology for the determination of triazines in environment al samples incorporating a molecularly imprinted solid-phase extraction (MI SPE) process using a propazine-imprinted polymer was developed. Two differe nt polymers were prepared using acetonitrile or toluene as porogen, and the ir optimum loading, washing, and elution conditions were established. Altho ugh both polymers were able to recognize several chlorotriazines (propazine , atrazine, simazine, desethylatrazine, and desisopropylatrazine), the poly mer prepared in toluene showed the best performance and was also capable of recognizing a methylthiotriazine (prometryn). A binding study carried out in this polymer demonstrated that it possesses heterogeneous binding sites with different binding abilities. From this study, it was also concluded th at desethylatrazine and desisopropylatrazine displace the other triazines a t high concentrations, including the template molecule. The accuracy and se lectivity of the MISPE process developed was verified using a certified ref erence material for drinking water containing atrazine and simazine among o ther commonly used pesticides. Finally, the MISPE procedure was successfull y applied to the cleanup of drinking and groundwater, soil, and corn sample extracts, and the triazines were determined by micellar electrokinetic chr omatography.