title: Chemically modified attapulgite with asparagine for selective solid-phase extraction and preconcentration of Fe(III) from environmental samples.
abstract: A new method that utilizes asparagine modified attapulgite as a solid phase extractant has been developed for preconcentration of trace Fe(III) prior to the measurement by inductively coupled plasma optical emission spectrometry. Characterization of the surface modification was performed on the basis of Fourier transform infrared spectra. The separation/preconcentration conditions of the analyte were investigated, including the pH value, the shaking time, the sample fl ow rate and volume, the elution condition and the interfering ions. At pH 4, the new adsorbent had relatively high capacity and enrichment factor compared to other methods reported so far. The adsorbed Fe(III) was quantitatively eluted by 2 mL of 0.5 mol L(-1) HCl. Common coexisting ions did not interfere with the separation. The detection limit of the method was 0.19 microg L(-1). The relative standard deviation was 3.4% (n=8) which indicated that the method had good precision for the analysis of trace Fe(III) in solution samples. The method was validated using two certified reference materials and has been applied for the determination of trace Fe(III) in biological and natural water samples with satisfactory results.
authors.affiliation: Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Zang
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Ruijun
authors.initials: R
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Hu
authors.forename: Xijun
authors.initials: X
authors.lastname: Chang
authors.forename: Yuemei
authors.initials: Y
authors.lastname: Cui
mesh_terms: D000327:Adsorption; D001216:Asparagine / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis*; D017616:Magnesium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry*; D017655:Silicon Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D052616:Solid Phase Extraction; D013057:Spectrum Analysis / Q000379:methods; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D017616:Magnesium Compounds; D017655:Silicon Compounds; D014874:Water Pollutants, Chemical; D001216:Asparagine; D007501:Iron; C026325:attapulgite