In the magnetically assisted chemical separation (MACS) process, usually magnetite nanoparticles coated with extractant are used to extraction of metal ions. The metal-loaded nanoparticles are then recovered using a magnetic field. The metal ions attached to magnetite nanoparticles are subsequently removed using a small volume of stripping agent. In the present study, Triocthylamine (TOA) functionalized magnetite nanoparticles (TOAFM) were applied as the novel adsorbent for extraction of Iridium from acid solutions. In this research we prepared and used functional Fe 3 O 4 nanoparticles with Triocthylamine and used it as an ion exchanger for separation and extraction of Iridium Ion. Different method of characteristics such as ICP, IR-FT were used for investigating Ir Ion-exchange Synthesis. In order to obtain ideal condition for absorption of Iridium ion we have optimized effective parameters in absorption. These parameters included: determining optimum pH value and founded value was 1 Determining value of optimum absorption and the value was 6 mg, determining optimum concentration of metal and the value was 1 mg/lit, choosing a suitable detergent and we found C 2 H 3 O 2 NH 4 as a suitable detergent for Iridium , determining concentration of detergent and the value was 1M, finding time effect on absorption of Ir, effects of different temperatures on Ir absorption, effects of interfering metals on Iridium ion absorption and in this part we have investigated effects of interfering metals such as chromium (Cr), Nickel (Ni), Palladium(Pd), rhodium (Rh), Iron (Fe), Platinum (Pt) on absorption of Iridium ion and we also conducted measurement of true samples and we also found relative error, standard deviation and relative standard deviation, which were acceptable. With regard to these measurements we found absorbent capacity in different temperatures. In addition to this absorption, thermodynamic parameters of standard enthalpy , entropy and Gi free energy were calculated. With help of two-parameter, three-parameter and four-parameter isotherms in investigating errors equations we found best adaptation and the best adaptation in temperatures of 20, 30, and 40 are found. Key Words : Iridium, Adsorption, Magnetite nanoparticles , Isotherm, MACS process,TOA