Synthesis of Magnetic MCM-41 Mesoporous Functionalized with Dipicolinic Acid for Preconcentration and Determination of Some Cationic Dyes in Water Samples

The process of discharge of wastewater containing different amounts of dyes in the rivers, seas and oceans causes environmental problems because of the difficulty of disposing of them because of their non-biodegradable nature. As a result, their survival has harmful health effects on humans such as carcinogenicity, respiratory poisoning and fertility reduction .Depending on their chemical composition, dyes can be classified into anionic and positive dyes. Due to the presence of sulfonate groups of anionic dyes in its aqueous solution, it can show negative charge while due to the presence of amino or Sulphur containing groups of the cationic dyes in aqueous solution which show a positive charge .Numerous procedures were applied for the determination of dyes in different matrix, such as ion polarography, capillary electrophoresis,chromatography, and strip in Voltammetry, were suggested spectrophotometric technique for determination of various synthetic dyes. Solid phase micro extraction with usage of nanoparticles based adsorbent extensively applied for determination of dyes. In this study, the magnetic nanoparticle Fe3O4 protected with MCM-41 functionalized with dipicolinic acid or functionalized magnetic MCM-41, was synthesized and characterized as a new sorbent. Various techniques including fourier fransform infrared spectroscopy (FT-IR(, X-Ray Diffraction (XRD), energy dispersive X-ray (EDS), Thermogravimetric Analysis (TGA), Derivative Thermogravimetry (DTG), Differential Thermal Analysis (DTA) and BET were used for characterization of mesopprous. The magnetic properties of synthesized nanoparticles was investigated by vibrating sample magnetometer (VSM). This magnetic mesoporous, as a new solid phase was used for preconcentration of Methyl green dye in microextraction method. The preconcentrated dye was determined by spectrophotometric method. The effective parameters on the extraction efficiency including, adsorbent dose, pH, contact time, volume of eluent and ultrasonic bath time according to Taguchi design were investigated and optimized. Then, in the optimal conditions, the calibration curve of method was plotted and it was linear at the range of 0.008 – 0.750mgL-1. The preconcentration factor and the detection limit were 40.44 and 0.003 mgL−1 respectively. The effect of some external species including dye, cation and anions were investigated. The method was successfully applied to determined methyl green dye in several water samples including Yasouj tap water, Cheshmeh Mishi water and Bahrambieghi waterfall water.