Thesis (M.Sc.)--Chulalongkorn University, 2012

Sulfonic acid functionalized MCM-41-coated magnetic particles (Fe3O4/MCM-41/SO3H) which have magnetic properties for easy separation from sample media was synthesized. X-ray diffractometer (XRD), Fourier transforms infrared spectrophotometer (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analyzer (TGA) and surface area analyzer were employed for characterization of the synthesized solid. Fe3O4/MCM-41/SO3H adsorbent was used for extraction and isolation of creatinine from samples matrix prior to the analysis by Jaffé method. The influence of extraction parameters on the extraction efficiency were studied including sample pH, amount of adsorbent, sample volume, eluent concentration, extraction time and elution time. Moreover, the feasibility of reusing the adsorbent was also studied. The performance of the proposed method was investigated under chosen condition using the standard solution containing 10 and 50 mg/L of creatinine. The percent recoveries (%Recovery) and the percent relative standard deviations (%RSD) of the method were in the range of 95.3 - 98.8 % and 0.5 - 1.8 %, respectively. Furthermore, the method limit of detection (LOD) was 1.5 mg/L and the linear range could be extended up to 60 mg/L. From the analysis of spiked urine samples, the recoveries and relative standard deviation in the range of 96.7 - 99.5 and 0.2 - 1.0, respectively, were observed. The results show that the proposed method could apply for analysis of creatinine in human urine samples with acceptable accuracy and precision.