Fast and efficient adsorption of azure (Ⅱ) on nanoporous MCM-41 for its removal, preconcentration and determination in biological matrices

摘要

The objective of the present study was to investigate the potential of nanoporous MCM-41 silicate for the azure (Ⅱ) adsorption from the aqueous solutions. The method is based on the adsorption of azure (Ⅱ) after passing on MCM-41 in a column. The adsorption with respect to contact time, pH, flow rate of sample, eluent kind and volume was investigated to provide more information about the adsorption characteristics of MCM-41. After elution of the adsorbed dye, the concentrations of dye were determined by UV-Vis spectrophotometer. The method showed good linearity for the determination of azure (Ⅱ) in the range of 1-200 ng mL~(-1) with a regression coefficient of 0.9997. The limit of detection was 0.5 ng mL~(-1) and the relative standard deviation for 50 ng mL~(-1) of azure (Ⅱ) was 1.26 %. The adsorption properties of the MCM-41 were investigated using batch method. In order to investigate the efficiency of adsorption, pseudo-first-order, pseudo-second-order and intra particle diffusion kinetic models were studied. It was observed that the pseudo-second-order kinetic model fits better than other kinetic models with good correlation coefficient. Equilibrium data were fitted to the Langmuir model. Adsorption equilibrium reach within 5 min of contact time and adsorption capacity was found to be 66.0 mg g~(-1) The method was applied to the determination of azure (Ⅱ) in river water, broth culture medium and DNA samples.