Determination of iodide formed from inorganic iodine in aqueous solution

摘要: Abstract The analysis of the conversion iodine (I2) into-iodide (I− in borate buffer (0.23 M, pH 8) was examined using a variety methods. Reversed-phase liquid chromatography (LC) with an ion-pairing mobile phase employing either electrochemical (EC) or ultraviolet (UV) detection employed and results were compared those obtained electrochemically iodide-selective electrode spectroscopically by measuring absorbance increase at 226 nm due to I−. light two-step model rapid I2 hydrolysis yield equal amounts I− hypoiodous acid (HOI), followed slow disproportion HOI iodate (IO−3), giving final ratio IO−3 5 : 1. Independent method analysis, 84 ± 5% initial amount on gram-atom basis, consistent expected stoichiometry. determined their triiodide (I−3) appropriate presence excess time-dependent yields except for fact that completion 11 2% instead predicted 17%. At reaction times less than completion, varied, depending measurement. Only measurements gave accurate true picture concentration given point time. LC-UV LC-EC showed no change time, always maximum, acting as catalyst. In contrast, values too low (initially factor 2) when present, presumably owing interaction ion electrode. sensitivity measurement × 10−8 which, taken together selectivity reproducibility method, makes suitably reliable conducting these types measurements.