The Studies On Restricted Access Materials-Molecularly Imprinted Polymers Of Solid Phase Extraction For Recognition Of Organophosphorus

Molecularly imprinted polymers （MIP） for malathion were prepared by bulkpolymerization, using azobisisobutyronitrile as the thermal polymerization initiator. Theoptimum condition was obtained. The ratio of template molecule （malathion）, functionalmonomer （methacrylic acid） and cross-linker （ethylene dimethacrylate） was1:8:40, thereaction temperature was70℃, the amount of thermal polymerization initiator was1.5%.The maximum adsorption of MIP was8.62mg g^-1under the optimum conditions, whilemolecularly non-imprinted polymers was3.85mg g^-1. The absorption amount of ethoprophos,phorate, terbufos, dimethoate, malathion, and fenamiphos for molecularly imprinted polymerswere287.97，275.00，257.07，300.21，344.11，261.32μg g^-1, While the non-imprintedpolymers were142.37，137.58，130.00，143.43，112.34and123.98μg g^-1, respectively. Thepolymers were loaded into the solid phase extraction cartridge （SPE）. The optimum extractionconditions were selected water mixtures containing50%of methanol as the washing solventand methanol as the elution solvent. The extraction recoveries of malathion of the preparedMISPE （97.8%） were markedly better than C18SPE and Florisil SPE （82.8%and75.6%,respectively）.A novel restricted access materials combined to molecularly imprinted polymers, withmalathion as template molecule and glycidilmethacrylate （GMA） as pro-hydrophilicco-monomer, were prepared by suspension and precipitation polymerization under theoptimum conditions. The maximum adsorption of malathion of two restricted accessmaterials-molecularly imprinted microspheres were448.5,424.11μg g^-1, respectively.Restricted access materials-molecularly imprinted microspheres were used as the adsorbentenclosed in solid phase extraction column and the optimum extraction conditions was watermixtures containing50%of acetone was chosen as the washing solvent, methanol wasselected as the elution solvent. Compared with the molecularly imprinted microspheres andcommercial solid phase extraction columns, two restricted access materials-molecularlyimprinted solid phase extraction successfully restricted the interference of proteins and lipidsand selectively extracted six kinds of organophosphorus pesticides with the minimal samplepretreatment from spiked honey sample. The two new established methods showed goodlinearity in the range of0.01–10μg mL^-1, low limits of detection (0.005μg mL^-1). At levels of0.10and0.20μg mL^-1, the recoveries of spiked samples were95.7%,97.6%and96.1%and 98.2%, respectively, and the relative standard deviation （RSD） of were2.43%,2.26%,3.16%and3.25%, respectively.