Functionalized HMS mesoporous silica as solid phase extractant for Pb(II) prior to its determination by flame atomic absorption spectrometry.
In this work, a mesoporous silica has been chemically modified with 5-mercapto-1-methyl-1-H-tetrazol using the homogeneous route (MTTZ-HMS). This synthetic route involved the reaction of 5-mercapto-1-methyl-1-H-tetrazol with 3-chloropropyltriethoxysilane, prior to immobilization on the support. The resulting material has been characterized and employed as solid phase extractant for Pb(II). The effect of several variables (stirring time, pH, temperature, metal concentration, presence of other metals) has been studied using batch and column techniques. In batch experiments, 15 min stirring time, 55 degrees C and pH 8 were the optimal conditions for Pb(II) adsorption. In column experiments, sorption was quantitative for 1000 mL of 2.41 x 10(-4 )mM of Pb(II) solution and adsorbed ions were eluted out by 5 mL of 1 M HCl (preconcentration factor of 200). Spiked tap water was used for the preconcentration and determination of Pb(II) by flame atomic absorption spectrometry, and a 100% recovery was obtained. The LOD and LOQ values of the proposed method were found to be 3.52 x 10(-3) and 4.20 x 10(-3 )mM, respectively. The RSD for three preconcentration experiments was found to be <or= 2%. The linear working range for measurements was between 2 x 10(-3 )and 0.14 mM (y = 0.0136x + 0.0007, R(2 )= 0.9999).
Pérez-Quintanilla
Damián
D
Departamento de Química Inorgánica y Analítica, E.S.C.E.T, Universidad Rey Juan Carlos, C/ Tulipán s/n, Móstoles, Madrid, Spain.
Sánchez
Alfredo
A
del Hierro
Isabel
I
Fajardo
Mariano
M
Sierra
Isabel
I
D007854:Lead / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D008422:Materials Testing; D019216:Metals, Heavy / Q000032:analysis; D015394:Molecular Structure; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D013054:Spectrophotometry, Atomic / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared; D013777:Tetrazoles / Q000737:chemistry; D014961:X-Ray Diffraction
D019216:Metals, Heavy; D013777:Tetrazoles; C038625:1-N-methyl-5-thiotetrazole; D007854:Lead; D012822:Silicon Dioxide