Synthesis Of Novel Adsorption Materials And Their Solid-phase Extraction For Trace Elements

With rapid development of the world economy,the heavy metals caused severe pollution.The determination of the heavy metals is of important.Although many instrument analysis methods possessing higher sensitivity and selectivity have been developed recently,pretreatment of trace elements is still necessary,because classification of samples is complicated and concentration of analytes is extreme low. The solid-phase extraction is a simple,great efficiency and flexible method for pretreatment of the samples in recently.The research of the new sorbents which have high selection is of great importance for the solid-phase extraction.In the paper,new solid-phase sorbents were synthesized and the extraction performances of the sorbents for some ions were studied in detail.1.Zr(â…£)surface imprinted amino-functionalized silica gel material was firstly synthesized by combining a surface molecular imprinting technology.The experimental results showed that the ion-imprinted sorbent had higher selectivity and adsorption capacity for Zr(â…£).Under the optimal conditions,the relatively selective factor values of Zr(â…£)/Ti(â…£),Zr(â…£))/Y(â…¢)and Zr(â…£)/Nb(â…¤)were 32,34 and 50. The maximum static adsorption capacity of the ion-imprinted and non-imprinted sorbent for Zr(â…£)was 11 mg g^-1and 0.3 mg g^-1,respectively.2 mL of 3 mol L^-1HCl solutions can remove compeletely the absorbed Zr(â…£)from the sorbents.The method for determination of Zr(â…£)is fast,accurate and simple.2.A new solid sorbent,nanometer SiO₂ modified with phthalic anhydride,was prepared and applied to the selective solid-phase extraction of Pb(â…¡).The adsorption performances of the sorbents for Pb(â…¡)have been investigated following the batch procedure.Under the optimal pH 5.0,the adsorption equilibrium of Pb(â…¡)could be achieved in 2 minutes quickly.The quantitative elution of Pb(â…¡)can be obtained using 2 mL of 0.5 mol L^-1HCl.The maximum adsorption capacity reached 145 mg g^-1for Pb(â…¡).The presented method was applied to determine lead in food and soil samples with satisfactory results.3.Diaminothiourea was firstly binded on the surface of silica gel by reacting with 3-chloropropyltrimethoxysilane and then reacted with salicylaldehyde.Thus,a new solid-phase extractant with several complex groups was prepared.Analytical characteristics of the sorbents for Cr(â…¢),Cu(â…¡)and Hg(â…¡)have been investigated.A reliable method is restablished for the solid-phase extraction of trace Cr(â…¢),Cu(â…¡) and Hg(â…¡)in solution samples.Under the optimal conditions,the maximum static adsorption capacity of Cr(â…¢),Cu(â…¡)and Hg(â…¡)are 5.58 mg g^-1,14.5 mg g^-1and 40.6 mg g^-1,respectively.Common electrolytes have no evident interferences for adsorption and elution of the target analytes.