A Sampling and Analytical Method for Methyl Ethyl Ketone Peroxide

Abstract

A sampling and analytical method has been developed for measuring methyl ethyl ketone peroxide (MEK-P) exposures in the workplace. This method is unique because it provides a determination that is specific for the two major components of MEK-P found in commercial formulations. A commercial MEK-P formulation, which has been standardized with pure MEK-P monomer and pure MEK-P dimer, is used to prepare analytical standards. Fifteen-minute samples are collected at 1 L/min with adsorbent tubes containing XAD-4 resin. Collected samples remain stable for 15 days when stored at −25°C. The samples are extracted with 2-propanol and analyzed by normal phase high-performance liquid chromatography (HPLC). The resolved monomer and dimer are subjected to a postcolumn reaction that results in the production of quantitative amounts of iodine, which are quantitated with an ultraviolet detector. Earlier industrial hygiene methodology considered commercial formulations of MEK-P to be comprised of only the cyclic dimer. Reports in the literature clearly established that the cyclic dimer does not exist in commercial formulations, and the major components are the monomer and the dimer. Therefore, analytical results of earlier methodology relied on an incorrect equivalent weight for MEK-P. This problem has been eliminated in the procedure presented in this article.