title: Selective solid-phase extraction of trace thorium(IV) using surface-grafted Th(IV)-imprinted polymers with pyrazole derivative.
abstract: A new pyrazole derivative 1-phenyl-3-methylthio-4-cyano-5-acrylicacidcarbamoyl-pyrazole (PMTCAACP) was synthesized and chosen as a complexing monomer for the preparation of surface-grafted ion-imprinted polymers for selective solid-phase extraction of thorium(IV). The silica gel, modified with maleic anhydride, was prepared as a carrier material. In the ion-imprinting process, Th(IV) was complexed with PMTCAACP, and then imprinted in the polymers grafted to the surface of modified silica gel. Subsequently, the template Th(IV) ions were removed with 6 mol/L HCl solution. The obtained ion-imprinted particles for Th(IV) showed specific recognition, and rapid adsorption and desorption kinetics process. The maximum static and total dynamic adsorption capacity of the ion-imprinted polymers (IIPs) for Th(IV) was 64.8 and 37.4 mg/g, respectively. The relative selectivity coefficient values of the imprinted adsorbent for Th(IV)/U(VI), Th(IV)/Ce(III), Th(IV)/La(III), and Th(IV)/Zr(IV) were 72.9, 89.6, 93.8, and 137.2 times greater than non-imprinted matrix, respectively. The interference effect of common cations tested did not interfere with the recovery of Th(IV). The enhancement factor of 20.2, the detection limit of 0.43 microg/L, and the precision of 2.47% (n=7) of the method under the optimized conditions were obtained. Additionally, the calibration curve (r=0.9993) was linear in the range of 1.43-103 microg/L of thorium(IV). The prepared IIPs were shown to be promising for solid-phase extraction coupled with UV-vis spectrophotometry for determination of trace Th(IV) in real samples.
authors.affiliation: School of Chemistry and Chemical Engineering, University of South China, 28 Changsheng West Road Hengyang, Hunan 421001, PR China. lincanrong126@163.com
authors.forename: Canrong
authors.initials: C
authors.lastname: Lin
authors.forename: Hongqing
authors.initials: H
authors.lastname: Wang
authors.forename: Yuyuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Cheng
mesh_terms: D000327:Adsorption; D000577:Amides / Q000737:chemistry; D053000:Analytic Sample Preparation Methods; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008298:Maleates / Q000138:chemical synthesis / Q000737:chemistry*; D054802:Molecular Imprinting / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D052616:Solid Phase Extraction; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013816:Thermodynamics; D013910:Thorium / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: C549489:1-phenyl-3-methylthio-4-cyano-5-acrylicacidcarbamoyl-pyrazole; D000577:Amides; D008298:Maleates; D011108:Polymers; D011720:Pyrazoles; D013910:Thorium; D012822:Silicon Dioxide