Determination of trace lead in water samples by graphite furnace atomic absorption spectrometry after preconcentration with nanometer titanium dioxide immobilized on silica gel.
Nanometer titanium dioxide immobilized on silica gel (immobilized nanometer TiO2) was prepared by sol-gel method and characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). The adsorptive capability of immobilized nanometer TiO2 for lead was assessed in this work using column method. It was found that lead can be quantitatively retained by immobilized nanometer TiO2 in the pH range 4-7, then eluted completely with 1.0molL(-1) HCl. The adsorption capacity of immobilized nanometer TiO2 for Pb was found to be 3.16mgg(-1). A new method has been developed for the determination of trace lead based on preconcentration with a microcolumn packed with immobilized nanometer TiO2 prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS). The detection limit of this method for Pb was 9.5ngL(-1) with an enrichment factor of 50, and the relative standard deviations (R.S.D.s) was 3.2% at the 10ngmL(-1) Pb level. The method was validated using a certified reference material, and was applied for the determination of trace lead in water samples.
Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
Rui
R
Liu
Pei
P
Liang
D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007854:Lead / Q000032:analysis*; D053768:Metal Nanoparticles; D008855:Microscopy, Electron, Scanning; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014961:X-Ray Diffraction
D007202:Indicators and Reagents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D007854:Lead; D058428:Silica Gel; D012822:Silicon Dioxide; D014025:Titanium