Cigarette Smoke Formation Studies: Vll. The Fate of (5-14C)-Methoprene in Cigarette Smoke

An insect growth regulator, (5-¹⁴C)-methoprene [5-¹⁴C-isopropyl (2E,4E)-11methoxy-3,7,11-trimethyl-2,4-dodecadienoate], has been applied to tobacco filler from which cigarettes were made. The Kentucky 1R1 reference cigarette was employed in this study to determine the distribution of the (5-¹⁴C)-methoprene and its combustion and pyrolytic products in cigarette smoke. The distribution of smoke activity as determined using a total smoke recovery device showed 38.2 percent of the ¹⁴C-activity to be in mainstream smoke with 52.4 percent in sidestream and 8.1 percent filtered by the tobacco butt (23 mm). Analyses of mainstream particulate matter and gas phase by gas radiochromatography indicated the major portion of the activity found in mainstream smoke to be unchanged (5-¹⁴C)-methoprene (96.8 percent). Limited sidestream particulate matter analyses were also conducted. Analysis of the mainstream gas phase (1.3 percent of total activity) for carbon-14 distribution showed that carbon monoxide and carbon dioxide accounted for 86 percent of the gas phase activity. The remaining 14 percent was distributed among ten additional gas phase components.