Magnetic molecularly imprinted polymers based on carbon nanotubes for extraction of carbamates

A fast and economical method has been developed for the preconcentration of the carbamates propoxur, pirimicarb and promecarb by using magnetic molecularly imprinted polymers (m-MIPs). Propoxur was applied as the template for the analytes, and carbon nanotubes as a supporting template. The effects of the amount of magnetic sorbent, shaking time and rate, eluting solution on the extraction efficiency were studied. The processes of adsorption and desorption occur within 25 min, and the m-MIPs can be collected by applying an external magnetic field within 15 s. The m-MIPs were characterized by using FTIR, transmission electron microscopy, and with a vibrating sample magnetometer. The pesticides were quantified by HPLC with UV detection. Recoveries of spiked samples range from 90.5 to 98.6 %, and the lower detection limits range from 9.7 to 12.0 mu g kg(-1). The method is selective and convenient. The m-MIPs were successfully applied to enrich and determine the carbamates in spiked homogenates of apples, oranges and pears.