Indirect determination of ascorbic acid (vitamine C), iodide and thiosulfate by flame atomic absorption spectrometer

IV INDIRECT DETERMINATION OF ASCORBIC ACD3 (VİTAMİNE Q, IODD3E AND THIOSULFATE BY FLAME ATOMIC ABSORPTION SPECTROMETER (M.Sc. Thesis) Ozean YALÇINKAYA GAZI UNIVERSITY INSTITUTE OF SCTENCE AND TECHNOLOGY May 2005 ABSTRACT In this study, an indirect method by flame atomic absorption spectrometry has been developed for the determination of ascorbic acid, iodide and thiosulfate. In the developed method, it was used that the reduction of Cr(VI) to Cr(HI) by these analytes in acid medium. Cr(IH) produced by the reaction of analytes with Cr(VT) and excess Cr(VI) has been separated by a column filled with Amberlite XAD-16. Cr(DI) has passed through the column without retained while Cr(VI) has retained on the column. After eluting the retained Cr(VI), it has been determined by flame AAS and the contents of ascorbic acid, iodide and thiosulfate have been calculated by using reaction stoichiometry. Moreover, probable interference effect of some substances which may be present in real samples have also been investigated and the proposed method has been applied to the some real samples. The accuracy and the precision of the method has been acceptable level. Ascorbic acid, iodide and thiosulfate could be determined by the relative error below 10 % and relative standard deviation below 7%. Science Code : 201 KeyWords : Indirect determination, Ascorbic acid, Iodide, Thiosulfate, Amberlite XAD-16, Atomic absorption spectrometer Page Number: 95 Adviser : Prof. Dr. A. Rehber TÜRKER