title: Molecularly imprinted polymer layer-coated silica nanoparticles toward dispersive solid-phase extraction of trace sulfonylurea herbicides from soil and crop samples.
abstract: This paper reports the preparation of metsulfuron-methyl (MSM) imprinted polymer layer-coated silica nanoparticles toward analysis of trace sulfonylurea herbicides in complicated matrices. To induce the selective occurrence of surface polymerization, the polymerizable double bonds were first grafted at the surface of silica nanoparticles by the silylation. Afterwards, the MSM templates were imprinted into the polymer-coating layer through the interaction with functional monomers. The programmed heating led to the formation of uniform MSM-imprinted polymer layer with controllable thickness, and further improved the reproducibility of rebinding capacity. After removal of templates, recognition sites of MSM were exposed in the polymer layers. As a result, the maximum rebinding capacity was achieved with the use of optimal grafting ratio. There was also evidence indicating that the MSM-imprinted polymer nanoparticles compared with nonimprinted polymer nanoparticles had a higher selectivity and affinity to four structure-like sulfonylurea herbicides. Moreover, using the imprinted particles as dispersive solid-phase extraction (DSPE) materials, the recoveries of four sulfonylurea herbicides determined by high-performance liquid chromatography (HPLC) were 80.2-99.5%, 83.8-102.4%, 77.8-93.3%, and 73.8-110.8% in the spiked soil, rice, soybean, and corn samples, respectively. These results show the possibility that the highly selective separation and enrichment of trace sulfonylurea herbicides from soil and crop samples can be achieved by the molecular imprinting modification at the surface of silica nanoparticles.
authors.affiliation: School of Pharmacy, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Peng
authors.forename: Ying
authors.initials: Y
authors.lastname: Xie
authors.forename: Jing
authors.initials: J
authors.lastname: Luo
authors.forename: Li
authors.initials: L
authors.lastname: Nie
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.forename: Lina
authors.initials: L
authors.lastname: Chen
authors.forename: Shuhu
authors.initials: S
authors.lastname: Du
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D001190:Arylsulfonates / Q000737:chemistry*; D006540:Herbicides / Q000302:isolation & purification*; D054802:Molecular Imprinting; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012822:Silicon Dioxide / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D013453:Sulfonylurea Compounds / Q000302:isolation & purification*
chemical_list: D001190:Arylsulfonates; D006540:Herbicides; D013453:Sulfonylurea Compounds; C050296:metsulfuron methyl; D012822:Silicon Dioxide