Synthesis and Evaluation of Types of Shells on Fe3O4 Nanoparticles by SPME Method for Determination of Ti (IV) in Toothpaste by Spectrophotometry Using Experimental Design

摘要

Magnetic Solid Phase Microextraction (MSPME) was investigated as a safe, fast and inexpensive method to measure titanium element by the complex formation with 4-(2-Pyridylazo)-resorcinol as a ligand. First of all, the synthesized nanoparticles were coated with different shells including SiO2, TiO2, chitosan and active carbon. Then, the titanium adsorption cations were evaluated. The complex formation was measured via UV/Vis spectroscopy and the wavelength maximum absorption was determined at 520 nm.The optimization process was performed in two ways. First, eight parameters:pH, volume of aqueous phase (Vaq), sorbent amount (SA), organic solvent volume (V org), adsorption time (tads), desorption time (tdes), salt amount (NaCl) and ligand concentration (LC) were optimized by Plackett-Burman Design (PBD) in statistical software package Minitab ver. 17.0. Secondly, some parameters values were investigated for more confidence by One Variable at a Time (OVAT) method. Finally, the results demonstrated that the best condition of absorption of titanium cations is: Fe3O4@SiO2, acetonitrile as desorption organic solvent with 300 ml, volume and pH=3. The calibration curve was linear between 0.01and 0.6 μga????ml with a detection limit of 0.003 μg/ml, and Relative Standard Deviation (RSD %)( N=5) for concentration of 0.2 μga????ml was 4.2%. This method was used for toothpaste sample and an acceptable percentage of relative recovery (78.6%) was obtained.