Limitations of the Iodometric Determination of Ozone

摘要

Three popular variations of the iodometric determination of ozone were investigated using a spectrophotometric ozone monitor as the referee method. Determinations carried out with a neutral buffered potassium iodide reagent acidified to pH 2 with sulfuric acid were observed to give values that were 15-30 percent higher than those obtained with the unbuffered potassium iodide and Masschelein modification methods relative to the referee method. Sampling parameters such as flow rate were shown to have a marked effect on the determinations. Because of the technique-sensitive nature of the determinations, it is recommended that iodometry not be pursued as a standard method for measuring ozone.