Creatinine is a chemical waste that is produced by muscles and released in blood and removed by kidneys. The blood creatinine concentration ranges from 4 to 15 mg/L for healthy human, and may rise to around 100 mg/L for people with kidney disease .Hence, the determination of creatinine concentration in blood and urine is important to identify kidney problem. In this thesis, first the usual clinical method (Jafee Reaction) was tried with use of ion mobility spectrometer (IMS) as detector. However, ion mobility spectra of creatinine and creatine are exactly the same. In addition, the presence of other interfering species made the measurement of creatinine impossible. To selectively measure creatinine, solid phase micro extractions with molecular imprinted polymer as stationary phase, was used. In this method, to prepare the microextraction fiber, Fe 3 O 4 nanoparticles was first synthesized. Polyaniline was then growth on the surface of the nanoparticles to produced Fe 3 O 4 -polyaniline nanoparticles. In the next step, these nanoparticles together with aniline monomer and creatinine molecules were used as template for construction of Fe 3 O 4 -polyaniline- creatinine-aniline nanocomposite. A thin layer of the nanocomposite was magnetically coated over a needle and later electropolymerized at a constant voltage of 1 V for 15 minutes. By this way, molecular imprinted polymer was formed on the needle. For removing template molecules, the needle was inserted in a 0.5 M H 2 SO 4 standard solution with a constant voltage of -0.6 V for 5 minutes. Parameters for effective extractions were optimized, including extraction time, 5 minutes, temperature is 40 o C, pH 7 and ionic strength 150 ppm NaCl. Creatinine extraction was performed for real blood sample at optimized condition and its concentration was determined by IMS instrument. This method can screen healthy people from patients with kidney diseases.
