Studies On The Preparation Of Solid Phase Extraction Materials And Its Application On The Enrichment Of Environmental Pollutants

Solid phase extraction （SPE） is widely applied in the sample pretreatment since itsfirst proposed. No matter in the practical production or in the scientific research, theSPE technique has made great achievements and progresses. The SPE technique hasseveral developing trends as follows: Exploiting range of application of mature SPE,development of SPE device with rapid, easy manipulation, and full-automationrequirement, and study and research of new SPE materials which is the core of the SPEtechnique. Herein, we studied the synthesis, characterization and real application of anew magnetic SPE material, and we tried several ion-type SPE columns for theextraction of inorganic cation ions in the water.Hydrophilic carbon-functionalized magnetic microspheres coated with chitosan（Fe3O4@C@CHI） were synthesized for the first time. The hydrophilic carbonaceouslayer on the Fe3O4microspheres was formed by the hydrothermal reaction of Fe3O4microspheres and glucose, and then chitosan was coated on surface of thecarbon-functionalized microspheres by an easy zero-length reaction with EDC and NHSas cross-linkers. The Fe3O4@C@CHI microspheres were spherical core-shell structurewith uniform size at about400nm. The microspheres had a high saturationmagnetization of60.22emu g-1, which was sufficient for magnetic separation. TheFe3O4@C@CHI microspheres presented good hydrophilic property due to the abundantcarboxyl and hydroxyl groups on the carbonaceous layer of the microspheres. Thesuccessful modification of chitosan on the surface of carbon-functionalized magneticmicrospheres was validated by the adsorption of Eriochrome Black T （EBT）. Theprepared microspheres were applied as magnetic solid-phase extraction materials forextraction of bisphenol A （BPA） in aqueous samples. The extraction recoveries ofspiked samples were in the range of99.4-102.6%with low relative standard deviationsof2.8-3.9%. The results demonstrated that the novel Fe3O4@C@CHI microsphereswere good candidate as magnetic SPE materials for extraction of analytes from aqueoussamples.The method for detection of Na⁺，NH4⁺，K⁺，Mn²⁺，Ca²⁺，Ba²⁺was developed withion chromatography with a non-suppressed IC instrument. Then IC-H column, IC-PCX column, and IC-PWCX column from Agela technologies, and Strata-X-AW polymericWeak anion from Phenomenex company were chosen for the extraction of inorganiccation ions in the water. Results showed that the strong cation ion SPE column hasstrong interaction with the target ion, and it can`t be eluted from the SPE column. Andthe weak cation ion SPE column can get good result with weak interaction with targetion, but IC-PWCX column has interference of Na⁺and Ca²⁺. Finally, we chooseStrata-X-AW column as the SPE column for the extraction of six target ions, and therecovery was between of65.07%and113.32%.