GB909270A - Improvements relating to the meastirement of the concentration of strong oxidising agents in a relatively inert diluting gas - Google Patents

Abstract

909,270. Determining quantities of fluid mixture constituents. BREWER, A. W. Jan. 27, 1960 [Jan. 27, 1959], No. 2949/59. Class 37. An electrolytic cell for the extimation of strong oxidizing agents in an inert diluting gas, by passing the gas into the aqueous iodide electrolyte to liberate free iodine, includes a first electrode of a metal or metals of the platinum group, and a second electrode of a metal which reacts with nascent iodine, a potential difference being applied to the electrode such that the first electrode is negative, and of magnitude such that no current flows in the absence of free iodine. A glass vessel 1, Fig. 1, closed by a bung 4 contains a neutral buffered potassium iodide solution 2 through which a gas from the tube 3 can be bubbled by application of suction to tube 5. The anode 6 consists of a cup of fine platinum gauze, and the cathode 7 is of silver, which may be in the form of silver sponge. An electromotive force of about 0.42 volts is applied between the two electrodes. A second embodiment, Fig. 4, is similar, but the anode 8 is of mercury, and the solution flows slowly through the cell, from reservoir 9 which contains fresh solution and is connected to the cell vessel 1a by a capillary tube 10 filled with a chemically inert sand 11, to a constant head device consisting of a chamber 12 connected with the cell vessel 1a by capillary tube 14 and provided with an overflow 13. The cathode may, alternatively, be of gold amalgam, or of a base metal which reacts chemically with iodine. The apparatus and method are applicable to the measurement of ozone, hydrogen perioxide, fluorine, chlorine, or bromine, in air.