A New L-Cysteine-Functionalized Mesoporous Composite and Its High Selectivity Separation and Enrichment Properties for Hg(II)
A L-cysteine-functionalized mesoporous composite was prepared and modified by post-grafting method.The adsorption conditions were optimized and the adsorption property of the composite for Hg2+ was investigated.Effects of medium pH,adsorption time,and adsorbent dosage on Hg2+ adsorption were studied.The L-cysteine-functionalized mesoporous SBA-15 can selectively adsorb Hg2+ at pH 2.5 in case of the coexisted Cu(Ⅱ),Cr(Ⅵ),Cr(Ⅲ),Cd(Ⅱ).Hg2+ can be quickly eluated from the composite with a solution of 5% thiourea in 1 mol/L HCl.The detection limit for Hg2+ was 0.07μg/L,and the relative standard deviation(RSD) was 2.2%(CHg2+=1.0 mg/L,n=11).The presented procedure has been applied to the Hg2+ determination in waste water with the recovery in the range of 92%-101%.