The derivatization of molecular iodine to iodoform and its determination by adsorptive stripping voltammetry

The determination of elementary iodine in aqueous solutions is possible by a preliminary liquid–liquid extraction into benzene, followed by a derivatization to iodoform with alcoholic KOH solution. The iodoform is measured by adsorptive stripping voltammetry at a signal which corresponds to the reaction\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm HCl}_{\rm 3} + {\rm H}^ + + 2{\rm e}^ - \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}} {\rm H}_{\rm 2} {\rm Cl}_{\rm 2} + {\rm I}^ - $$\end{document} The calibration plot is linear up to 1 × 10 −5 mol/L. The detection limit is at least 2 × 10 −8 mol/L and the standard deviation of the entire analytical procedure is 10%. The procedure is applicable to seawater.