Determination of 10 Sulfonylurea Herbicides by High Performance Liquid Chromatography-Tandem Mass Spectrometric with Molecularly Imprinted Polymers Solid Phase Extraction Doped Metal Organic Frameworks

To develop an efficient method for simultaneous detection of sulfonylureas,molecularly imprinted polymer(MIP)was successfully synthesized by precipitation polymerization using metsulfuron-methyl as template,4-ethylene pyridine(4-VP)as functional monomer and ethylene glycol dimethacrylate(EGDMA)as crosslinker. A mixed solid-phase extraction cartridge was obtained by packing the MIP and the metal organic frameworks(MOFs)at proper amount. A high throughput method was established for trace analysis of 10 kinds of sulfonylurea herbicide pesticides(monosulfuron,metsulfuron-methyl,thifensulfuron,chlorsulfuron,prosulfuron,triflusulfuron-methyl,chlorimuron-ethyl,nicosulfuron,bensulfuron-methyl and pyrazosulfuron-ethyl)in rice samples by the mixed solid phase extraction coupled with HPLC-MS/MS.The characterizations of the MIP and MOFs were respectively performed with scanning electronic microscope. The solid phase extraction conditions including activator,loading solutions,washing solutions and elution solutions were optimized. The results showed that the optimal conditions were:Acetonitrile(5 mL) and water(5 mL) as activation solution,acetonitrile water(80%)as sample solution,water(3 mL)for elution,10 mL of acetic acid methanol(1:9,V/V)successively eluted with 5 mL of acetone,MIP(40 mg)mixed with MOFs(10 mg)as SPE column packing ratio. Under the optimum conditions,the limit of detection(LOD)ranged from 0.07 to 0.5 μg/kg. It showed a good linearity relationship in the range of 1~100 μg/kg with the relative coefficient(r>0.991). Besides,the average recoveries was in the range of 79.75%~99.05% with the relative standard deviation(RSD,n=3)of 6.7%~13.8%.The developed method possessed many advantages such as high sensitivity and strong stability,and would be suitable for the rapid and class-specific determination of sulfonylurea herbicide pesticides in rice samples.