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Preconcentration And Determination Of Trace Mercury(â…¡) Using Chemically Modified Silica Gel With Schiff Base

Posted on:2013-06-12Degree:MasterType:Thesis
Country:ChinaCandidate:C J LiFull Text:PDF
GTID:2254330425492539Subject:Nutrition and Food Hygiene
Abstract/Summary:PDF Full Text Request
A novel material was designed and prepared with Modified silica gel using schiff base contained more electron atoms such as N,S,O, which was employed to extract Hg(II) from water and food samples prior to analysis by hydride generation atomic fluorescence spectrometry (HG-AFS).The performance of new synthesized ATTCH-SG was studied and evaluated. The ATTCH-SG was characterized by ESI-MS, FT-IR. Then, Isotherm and kinetics of adsorption were studied and the experimental data fits the Langmuir model and pseudo-second-order equation very well.The ATTCH-SG demonstrated to be good adsorbent for separation and preconcentration of Hg(II). Factors that influence the preconcentration procedure were optimized and studied, such as sample pH, sample flow rate, sample loading time and eluting solution. The results showed that, in weakly acid;(?)ation, Hg(Ⅱ) were best adsorbed by ATTCH-SG, the optimum pH of sample solution was6.0, the enrichment factors for above metal ions were173. The detection limit (3SD) was found to be0.0146μg L-1. The relative standard deviation of11replicate extractions of1.0μg L-1level were1.31%.The tolerance limit of coexistent ions was also investigated. The presence of500mg L-1(50000-fold) species Mg(Ⅱ), Na(Ⅰ), Zn(Ⅱ),400mg L-1(40000-fold) Al(Ⅲ),250mg L-1(25000-fold) Ca(Ⅱ),200mg L-1(20000-fold) Mn(Ⅱ), Fe(Ⅲ), K(Ⅰ),150mg L-1(15000-fold) Ag(Ⅰ), Ni(Ⅱ), Cr(Ⅲ),100mg L-1(10000-fold) Cd(Ⅱ), Pb(Ⅱ), As(Ⅲ) and80mg L-1(8000-fold) Cu(Ⅱ) had no significant effect on the extraction and determination of10.0μg L-1Hg(Ⅱ). The column was stable in operation process, enabling more than50adsorption-elution cycles without decreasing in the recoveries of the studied target ions.The recoveries of analyte spiked river water and food samples ranged from88~102%. The proposed method was validated by determination of analyte in certified reference materials and was shown to be promising for the determination of Hg(Ⅱ) in real water and food samples.
Keywords/Search Tags:modified silica gel, schiff base, solid-phase extraction, metal ions analysis, HG-AFS
PDF Full Text Request
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