Microwave Heating in Preparation of Magnetic Molecularly Imprinted Polymer Beads for Trace Triazines Analysis in Complicated Samples

Abstract

The use of microwave heating for preparation in organic synthesis has been accepted as an effective technique in synthesis due to the significant advantages over the conventional method. In the present work, microwave heating was applied to the preparation of atrazine (template molecule) magnetic molecularly imprinted polymer (mag-MIP) beads by suspension polymerization. The term of the polymerization was dramatically shortened by using microwave heating in polymerization, which was less than (1)/(10) that by conventional heating. The resultant polymers incorporating molecular recognition and magnetic separation can provide a highly selective material for trace analysis in complicated samples. The mag-MIP beads were demonstrated with a narrow diameter distribution (80-250 microm) and cross-linking, spherical shape, and porous morphologies and exhibited magnetic property (M(s) = 0.491 emicro/g) and thermal stability under 260 degrees C. An improvement of imprinted efficiency is obtained in comparison to the mag-MIP beads prepared by conventional heating. A method for the determination of triazines in complicated samples by the mag-MIP beads extraction coupled with high-performance liquid chromatography (HPLC) was developed. The results indicated that the mag-MIP beads can be favorably used for the extraction of the triazines in spiked soil, soybean, lettuce, and millet samples. The reused beads displayed a long-term stability after undergoing extraction of 100 times.