Development of a competitive format sorbent assay for the determination of parathion in water using molecular imprinted polymer as specific sorbent carrier

A rapid, simple, and reliable competitive molecular imprinted polymer sorbent assay (MIPSA) was developed and validated for measurement of parathion in water samples. This assay employed a molecular imprinted polymer (MIP) that was synthesized with non-covalent imprinting method as capture reagent and p-aminoparathion conjugate of horseradish peroxidase (para-HRP) as an enzyme label. The assay depended on a competitive binding reaction between the enzyme conjugate and analyte for the binding sites of the MIP. The optimized analysis conditions of 10 ng mL−1para-HRP and 10 mg mL−1 polymer were found. The assay was acceptable to detect parathion in water samples under the optimized conditions, with a limit of detection of 50 ng mL−1. Mean analytical recoveries of added parathion in water samples ranged from 101.2% to 105%. The precision of the assay was satisfactory; relative standard deviation ranged from 4.3% to 6%.