A Dropping Mercury Electrode of Improved Sensitivity

Abstract

Lingane and Loveridge¹ have recently emphasized the desirability of using a capillary electrode with drop-time between one and six seconds in polarographic work. For a given tube, the -drop-time (Ï) is inversely proportional to the rate of flow of mercury (m), which may be increased by altering the height of the mercury reservoir or the dimensions of the capillary. The polarographic sensitivity (iD/C) is proportional to m^2/3Ï/^1/6, or, in terms of the rate of increase of surface area of the drop If the rate of flow of mercury is increased sufficiently, the mercury no longer issues from the orifice in discrete drops, but in a fine stream. It has been possible, however, by constructing a capillary tube with orifice larger than the bore higher in the tube, to use an increased rate of flow of mercury without simultaneously increasing the drop-time.