1,4-Diazabicyclo [2.2.2] Octane Functionalized Mesoporous Silica SBA-15 (SBA-15@DABCO): a Novel Highly Selective Adsorbent for Selective Separation/Preconcentration of Cr(VI) from Environmental Water Samples

In this research, the potential application of 1,4-Diazabicyclo[2.2.2]octane (DABCO) functionalized mesoporous SBA-15 (SBA-15@DABCO) was evaluated as a new and efficient adsorbent for the selective separation/preconcentration of Cr(VI) ions in water samples, before assaying by flame atomic absorption spectrometry (FAAS). The mesoporous nanocomposite (SBA-15@DABCO ) was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, Transmission Electron Microscopy (TEM), Thermal gravimetric analyzer (TGA), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) method. The experimental parameters influencing the recovery of Cr(VI), including sample pH, initial volume of solution, eluent type and its volume and interfering effect were investigated and optimized. The fitting experimental data with conventional isotherm models showed that the adsorption of Cr(VI) on SBA-15@DABCO followed the Langmuir model and the maximum adsorption capacity was 140.8 mg g −1 . Under the optimal conditions, this method gave a linear calibration curve in the range of 25 to 2000 ng mL −1 for the determination of Cr(VI) and the limit of detection (LOD) was estimated to be 7.0 ng mL −1 . Finally, the developed method has been successfully used for the determination of Cr(VI) in different environmental water and wastewater samples and good recoveries was obtained.