Preparation Of Functional Magnetic Solid Phase Extraction Reagent For Rubidium Ion

Qinghai is world-famous for its abundant salt lake resources.The development of the salt lake industry has become one of the four pillar industries in Qinghai Province.The salt lake brine has at least 62.2 million tons of Rb₂O,but the average concentration of cerium ions is scarce?the average concentration is about 10.8 mg/L?.Concentrations of associated K⁺,Na⁺,Ca²⁺,and Mg²⁺ions in brine are often several hundred or even several thousand times larger than Rb⁺,which lead great difficulties for the separation,enrichment,and quantitative detection of rubidium ion.The traditional rubidium extraction technology mainly includes precipitation method,solvent extraction method and ion exchange method,which have some disadvantages,such as expensive,complicated and poor selectivity,deleterious and unstabitily.The main detection methods of rubidium ion contain atomic absorption spectrometry?AAS?,X-ray fluorescence spectrometry?XRF?,inductively coupled plasma emission spectrometry?ICP-AES?,inductively coupled plasma mass spectrometry?ICP-MS?,etc.However,some limitations still exist in these methods,such as costly,low detection limit,poor accuracy.Therefore,the research of new materials or new methods that can be applied to the separation and extraction of rubidium ions in low concentration and high salt solutions will be the focus of future scientific research.Based on this,in this paper,the preparation of rubidium ion extractant was combined with magnetic solid phase extraction technology.Two kinds of magnetic solid phase extractants with selectivity for rubidium ions were prepared and the adsorption was discussed.Specifically,it includes:?1?A benzene-boron-modified magnetic solid phase extractant was prepared on the basis of Fe₃O₄@SiO₂ nanospheres.The product was characterized by IR,TEM,EDS,SEM and XRD.The results of adsorption capacity showed that pH=9.5,the saturated extraction capacity was 465.68?g/g at 35 minutes.The adsorption rate was87.6%after five adsorption-elution cycles,extraction agent has high extraction of rubidium ion in simulated brine.?2?A valinomycin-modified magnetic solid phase extractant was prepared.The product was characterized by FT-IR,SEM,TGA,XRD,EDS and TEM.At 50?and pH=9.3 the extraction equilibrium could be reached in 30 minutes,and the saturated extraction capacity was 924.06?g/g.The adsorption rate was 85.3%after five adsorption-elution cycles,extraction agent has high extraction of rubidium ion in simulated brine.?3?A crown ether-modified magnetic solid phase extractant was prepared on the basis of Fe₃O₄@SiO₂ nanospheres.The product was characterized by FT-IR,TEM,XRD.The extraction amount of rubidium ion at 10 minutes and 35°C was 808.26?g/g.The extraction amount was 1145.12?g/g when the amount of catalyst is 0.125g.