Abstract: An amperometric method for the detection of cyanide has been developed based on the anodic dissolution of gold in solutions containing cyanide. The method is characterized by a cyclic regeneration of the electrode surface. During the regeneration, the surface layers on the electrode are dissolved. By selection of suitable measuring potentials for the cyanide, linearity can be shown to exist between current and cyanide concentration over the concentration ranges from 0 to 10 mg/l and 10 to 100 mg/l. The lowest detection level is about 0.05 mg CN-/l. Determinations in the concentration range investigated are possible at a measuring potential of E=270 mV. The method is suitable for detecting the end point during the decontamination of cyanide-containing sewage. The influence on the results of pH, temperature, flow rate, heavy metal content, type of decontamination agent and the presence of brighteners is discussed.

Abstract: Voltammetric investigations of ferrocene in organic media with planar, disk and band shaped microelectrodes (ME) and microarrayelectrodes (MAE) were carried out in stationary solutions and under flow-through conditions with flow injection analysis (FIA). The electrodes were embedded in cylindrical electrode bodies made of epoxy resin. During the FIA experiments miniaturized flow-through cells with a three electrode configuration (wall-jet, thin-layer principle) were used. As detectors microelectrodes and microarrayelectrodes consisting of platinum wires (radius: 10 µm), gold wires (radius: 12.5 µm), carbon fibers (radius: 3.5 µm) and gold foils (foil thickness: 30 µm) were constructed using fine precision manufacturing methods by sealing the electrode materials in insulating resins.