Flow injection determination of iodide ion in a photographic developing solution using iodide ion-selective electrode detector

A potentiometric flow injection determination method for iodide ion in a ph otographic developing solution was proposed by utilizing a flow-through typ e iodide ion-selective electrode detector. The sensing membrane of the elec trode was Ag2S-AgI membrane. The response of the electrode detector as a pe ak-shape signal was obtained for injected iodide ion in a photographic deve loping solution. A linear relationship in the subnernstian zone was found t o exist between peak height and the concentration of the iodide ion in a ph otographic developing solution in a concentration range from 0 to 6.0 x 10( -5) mol 1(-1). The relative standard deviation for ten injections of 2 x 10 (-5) mol 1(-1) iodide ion in a photographic developing solution was 0.96% a nd the sampling rate was approximately 12-13 samples h(-1). The iodide ion could be determined under coexisting of an organic reducing reagent and ino rganic electrolytes of high concentration in a photographic developing solu tion sample solution by the present method. (C) 2000 Elsevier Science B.V. All rights reserved.