The tritium kinetic isotope effect for the iodination of L-(5-³H)-3-Iodotyrosine

Abstract

The kinetic tritium isotope effect (k_H/k_T) for the iodination of L-(5-³H)-3-iodotyrosine at pH 7·5 was found to be 4·29±0.25 with molecular iodine and 4·50±0.26 with chloramine-T/potassium iodide. This effect establishes that the rate-limiting step is proton removal by the general base. A novel method for measuring the fraction of tritiated water by high performance liquid chromatography is described.