title: Preparation of xylenol orange functionalized silica gel as a selective solid phase extractor and its application for preconcentration--separation of mercury from waters.
abstract: A new selective solid phase extractor was prepared from silica gel modified with xylenol orange (SGMXO). The solid phase extractor is stable in 6molL(-1) HCl, common organic solvents, and pH 1.0-9.0 buffer solutions. In the batch experiments, Hg(II) can be adsorbed on SGMXO at pH 1.0 with 90.0% retention, whereas the retention of other common coexisting metal ions such as Cd(II), Pb(II), Cu(II), Ni(II), Co(II), Mn(II), Zn(II), and Fe(III) is less than 4.1%.. The adsorption equilibration for Hg(II) was achieved within 3min. At optimum conditions, the adsorption capacity of the extractor is 18.26micromolg(-1) of dry modified silica gel, and the preconcentration factor is as high as 333. The recovery is still higher than 95% for the preconcentration of 10ngmL(-1) Hg(II). The new solid phase extractor has been used for the preconcentration of low level of Hg(II) in surface water, tap water in chemistry laboratory and student's dormitory and a simulated sea water samples, recoveries of 98.2-100.6% were obtained. It is showed that low level of Hg(II) can be effectively preconcentrated by this new selective solid phase extractor.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China. fanjing@henannu.edu.cn
authors.forename: Jing
authors.initials: J
authors.lastname: Fan
authors.forename: Chunlai
authors.initials: C
authors.lastname: Wu
authors.forename: Yafang
authors.initials: Y
authors.lastname: Wei
authors.forename: Chuanyun
authors.initials: C
authors.lastname: Peng
authors.forename: Pingan
authors.initials: P
authors.lastname: Peng
mesh_terms: D000327:Adsorption; D017669:Mercury Compounds / Q000302:isolation & purification*; D008956:Models, Chemical; D015394:Molecular Structure; D010636:Phenols; D012680:Sensitivity and Specificity; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods; D013454:Sulfoxides; D013499:Surface Properties; D014867:Water / Q000737:chemistry*; D014992:Xylenes / Q000737:chemistry*
chemical_list: D017669:Mercury Compounds; D010636:Phenols; D013454:Sulfoxides; D014992:Xylenes; D014867:Water; D058428:Silica Gel; D012822:Silicon Dioxide; C016833:xylenol orange