The adsorptive and electrochemical behaviors of clozapine (CLZ) were investigated on a glassy carbon electrode that was electrochemically treated by anodic oxidation at +1.8 V, following potential cycling in the potential range from -0.8 to 1.0 V vs. Ag/AgCl reference electrode. Based on the obtained electrochemical results, an electrochemical-chemical (EC) mechanism was proposed to explain the electrochemical oxidation of CLZ. The resulting electrochemically pretreated glassy carbon electrode (EPGCE) showed good activity to improve the electrochemical response of the drug. CLZ was accumulated in a phosphate buffer (pH 6) at a certain time, and then determined by differential pulse voltammetry. The anodic and cathodic peak currents showed a linear function in the concentration ranges of 0.1 -1, 1 -10 and 10 -100 μM with various accumulation times. The proposed method was successfully used for the determination of CLZ in pharmaceutical preparations. The preconcentration medium-exchange approach was utilized for the selective determination of the drug in spiked urine samples with satisfactory results. The recovery levels of the method reached 96% (RSD, 1.8%) and 90% (RSD, 2.8%) for urine and plasma samples, respectively.

The electrooxidation of hyoscine N-butylbromide (HBB) was investigated by rotating disk electrode voltammetry, cyclic voltammetry and controlled potential coulometry in 0.1 M HNO 3 and in 0.1 M tetrabutylammonium perchlorate (TBAP) solutions of acetonitrile at a platinum (Pt) electrode. Based on the results obtained, it is suggested that a bromide ion of HBB was oxidized in one reversible step in aqueous solutions and in two reversible steps in acetonitrile. A differential pulse voltammetric (DPV) method at a Pt electrode was developed for the determination of HBB in the concentration range of 1.0´10 -6 -1.01 0 -3 M. The procedure was applied to the determination of HBB in its formulations as well as its recovery from blood serum and urine samples.

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Layer-by-layer of Ni/Ni(OH)2 particles were deposited on Steel Gauze (SG) electrode via cathodic electrodeposition. The system with two electrodes was selected for electrodeposition in the galvanostatic condition. Electrodeposition of the first layer of Nickel was conducted in the electrochemical cell with an SG substrate as a cathode. This electrode was fixed between two parallel graphite anodes and electrodeposition was performed from a mixture of NiCl2, NH4Cl, NaCl solution. Electrodeposition of the second layer of Ni(OH)2 on the Ni layer which has been formed in the first step, was carried out in the same way from a solution containing Ni(NO3)2. TG, XRD and SEM techniques were used for the characterization of the prepared SG/Ni/Ni(OH)2 electrode. The prepared SG/Ni/Ni(OH)2 electrode was analyzed by electrochemical techniques such as Cyclic Voltammetry (CV), galvanostatic charge–discharge and Electrochemical Impedance Spectroscopy (EIS). The SG/Ni/Ni(OH)2 electrode demonstrated high specific capacity (1308 C g−1 at the scan rate of 5 mV s−1) and excellent cycling ability (8.9% capacity decay at the current density of 50 A g−1 after 1000 cycle).