Thesis (M.Sc.)--Chulalongkorn University, 2001

In this research, electrochemical analysis of drugs using a boron-doped diamond thin film electrode has been studied. Drugs, including acetaminophen, D-penicillamine and barbituric acid were investigated. The electrochemistry of drugs was studied by cyclic voltammetry. Comparison experiments were carried out using a polished glassy carbon (GC) electrode. At the diamond electrode, well-resolved cyclic voltammograms were obtained with current signal to background ratios higher than that obtained from the glassy carbon electrode. Detection limits of 10, 25 and 50 micrometre for acetaminophen, D-penicillamine and barbituric acid, respectively were obtained at the diamond electrode. Flow injection with amperometric detection using the diamond electrode was also studied. A significant low detection limit at 10 nM with signal to noise ratios higher than 3 and a linear range over 2-3 orders of magnitude were obtained. The purposed method was further applied to real drug samples in pharmaceutical preparations. These were paracetamol syrup and penicillamine capsule. The results obtained were satisfactory.