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 photographic developing solution was proposed by utilizing a flow-through type iodide ion-selective electrode detector. The sensing membrane of the electrode was Ag(2)S-AgI membrane. The response of the electrode detector as a peak-shape signal was obtained for injected iodide ion in a photographic developing solution. A linear relationship in the subnernstian zone was found to exist between peak height and the concentration of the iodide ion in a photographic developing solution in a concentration range from 0 to 6.0x10(-5) mol l(-1). The relative standard deviation for ten injections of 2x10(-5) mol l(-1) iodide ion in a photographic developing solution was 0.96% and the sampling rate was approximately 12-13 samples h(-1). The iodide ion could be determined under coexisting of an organic reducing reagent and inorganic electrolytes of high concentration in a photographic developing solution sample solution by the present method.
Sensitive flow-injection amperometric detection of iodide using Mn3+ and As3+.
A rapid, selective, and sensitive kinetic flow-injection method for iodide content determination with amperometric detection on a platinum electrode was developed. The method is based on the catalytic effect of iodide on the Mn3+ reaction with As3+ in the presence of sulfuric acid. The calibration curve was linear in the concentration range from 5.0 x 10(-7) to 1.0 x 10(-4) mol/L iodide. The limit of detection (LOD) was found to be 5.0 x 10(-9) mol/L iodide. The relative standard deviations (RSD) were 1.68% and 3.03% for 1.0 x 10(-3) mol/L standard and 1.0 x 10(-6) mol/L iodide solution (n = 6), respectively. The method has been successfully applied for determination of iodide in waters, table salts, fodder, organic substances and human blood sera. The results were compared with those obtained by a standard AOAC (Association of Official Analytical Chemists) method, as well as with those obtained by a kinetic spectrophotometric procedure for determination of iodide.
Selective etching of InP in NaF solution
Abstract The crossing porous structure of InP has been obtained by electrochemical etching in NaF solutions. The behavior of the periodic oscillation occurs at different potential ranges for the different concentrations of solutions, and it will disappear with the concentration of the solution decreased. The scanning electron microscope (SEM) image shows that the pores have two directions on the surface and are perpendicular to each other. The two directions are assigned to [0 1 1] and [ 0 1 ¯ 1 ], respectively. The SEM image of the cross-section also shows that the two directions are assigned to [1 1 1]B and [ 1 1 ¯ 1 ¯ ]B. Both are due to the selective etching of F− ions. The crossing porous structure of InP is a very promising feature for the three-dimensional structure of III–V compound semiconductors for photonic band gap materials.