| Rare and precious metals are widely used in electronics,military,petrochemical,metallurgical,aerospace and other fields.Moreover,trace precious metals in mineral samples may reflect important source information related to the geological origin of certain minerals.On the other hand,some rare precious metal compounds are directly exposed to the environment,which will also cause potential harm to human health.Because the content of rare precious metals in the environment is extremely low,the matrix interference is large,and it is difficult to directly determine its level,so it is necessary to combine solid phase extraction(SPE)and other pretreatment techniques to accurately determine trace metal elements in environmental and mineral samples.In recent years,some novel SPE adsorbents based on ion-imprinted polymers(IIPs)are widely used in many fields because of their specific recognition selectivity for target metal ions.In the preparation process of IIP,the target ion is used as template to combine with functional monomer through electrostatic or coordination,the resulting IIP is specific and have high selectivity for certain metal ions.However,the highly cross-linked network structure of traditional IIPs is likely to cause problems such as slow mass transfer rate,embedding of identification sites,and poor mechanical stability.In order to improve the adsorption performance of ion-imprinted materials,we use surface ion-imprinting technique based on organic-inorganic hybrid monolithic material,the magnetic material was chosen as solid-phase carriers in the imprinting process,the separation and enrichment of cerium and gold were realized by magnetic solid phase extraction(MSPE),and combined with inductively coupled plasma mass spectrometry(ICP-MS)detection technology for quantitative analysis of trace target metal elements in environmental and mineral samples.The detailed work is as follows:1.Fe3O4 nanoparticles were synthesized by solvothermal method,and then a one-pot method was used to prepare vinyl functional organic-inorganic hybrid monolith(HM)on its surface.This method is more convenient than the step-by-step wrapping method,the resulting Fe3O4@HM has a more stable structure and with better thermal and chemical stability.Then Ce(Ⅲ)was used as template ion,acrylamide(AM)as the functional monomer,ethylene glycol dimethacrylate(EGDMA)as the crosslinking agent,and azobisisobutyronitrile(AIBN)as the initiator,surface ion-imprinting technique was used to prepare magnetic cerium ionimprinted polymer(Ce(Ⅲ)-MIIP)on the surface of Fe3O4@HM,which was used as MSPE adsorbent for rapid separation and enrichment of Ce(Ⅲ).The as-prepared materials were characterized by scanning electron microscopy(SEM),transmission electron microscope(TEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),thermogravimetric analysis(TGA),and vibrating sample magnetometry(VSM),etc.The conditions of p H,adsorption time,sample volume,eluate concentration and volume were optimized,under the optimized conditions,Ce(Ⅲ)-MIIP was used MSPE for separation and enrichment of Ce(Ⅲ),and was determined by inductively coupled plasma mass spectrometry(ICP-MS).It has a high specific selectivity for Ce(Ⅲ)in the environment containing competing ions,Ce(Ⅲ)-MIIP has strong anti-interference ability in the environment of high concentration interference ions.The reliability of the method was verified by the spiked recovery of real samples,the MSPE-ICP-MS method based on Ce(Ⅲ)-MIIP can be applied to the analysis of Ce(Ⅲ)in environmental water samples.2.By introducing solvothermal method for generating Fe3O4 nanoparticles and“one-pot” method for synthesizing organic-inorganic hybrid monolithic vinyl functionalized Fe3O4(Fe3O4@HM).Then,Au(Ⅲ)was used as template,1-Vinyl imidazole(VIM)as functional monomer,EGDMA as cross-linker,and AIBN as initiator,magnetic gold ion-imprinted polymer(Au(Ⅲ)-MIIP)was successfully synthesized by free radical polymerization.The materials were characterized and analyzed by means of SEM,TEM,FT-IR,XRD,TGA and VSM.After the optimum conditions including solution p H,adsorption time and sample volume,eluent composition and volume,and elution time were investigated,the Au(Ⅲ)-MIIP was employed as MSPE matrix for pretreatment and enrichment of trace gold ions followed by ICP-MS determination with excellent selectivity and strong anti-interference ability.The reliability of this method was verified by using corresponding Certified Standard Reference materials and spiking recovery of the real samples analyzed.The applicability superiority of this Au(Ⅲ)-MIIP was confirmed by the rapid and efficient extraction of trace level Au(Ⅲ)in environment water,sediment,soil,coal and ore samples with satisfactory results.The MSPE-ICP-MS method based on Au(Ⅲ)-MIIP can be applied to the analysis of Au(Ⅲ)in environmental and mineral samples. |
