Determination of triiodide ion concentration using UV-visible spectrophotometry

Abstract

The concentration of triiodide ions was determined using UV-visible spectrophotometry. The maximum absorption λmax for the analysis of triiodide ions were observed at 288 and 351 nm, with molar absorptivity values of 2.65 × 104 and 1.72 × 10 4 L cm-1 mol-1, respectively. The absorbance of triiodide ions had little effects on the solution pH in the range of 2.0 to 6.5. However, the absorbance strongly depended on the iodide ion concentration. Consequently, we confirmed that triiodide ion concentrations in the range of 0.005-0.1 mM could be determined using UV-visible spectrophotometry.