Pyrolysis of [14C]-chlorantraniliprole in tobacco.

The pyrolysis of [(14)C]-chlorantraniliprole {3-bromo-1-(3-chloro-2-pyridinal)-N-[4-chloro-2-methyl-6-[(methylamino)carbonyl]phenyl]-1H-pyrazole-5-carboxamide} in tobacco was examined. Typically five commercially available cigarettes were treated separately with either [pyrazole carbonyl-(14)C] or [benzamide carbonyl-(14)C]-chlorantraniliprole at a concentration of 20 ppm (μg chlorantraniliprole equivalent/g cigarette weight; main study) to 40 ppm (for degradate identification only). All treated cigarettes were smoked using an apparatus designed to collect mainstream (MS) and sidestream (SS) smoke through a glass fiber filter and a series of liquid traps. The material balance for recovery of applied radiolabel ranged from 92.4 to 94.9%. Unchanged chlorantraniliprole was the major component found in butt and filter extracts, averaging a total of 17.4-17.9% of the applied radioactivity. A nonpolar degradation product, 2-[3-bromo-1-(3-chloro-2-pyridinyl)-1H-pyrazol-5-yl]-6-chloro-3,8-dimethyl-4(3H)-quinazolinone, designated 1, represented an average of 10.1-15.9% of the applied radioactivity in the [pyrazole carbonyl-(14)C] or [benzamide carbonyl-(14)C]-chlorantraniliprole cigarettes, respectively. (14)CO(2) was the major degradate, representing an average of 32.9 and 25.1% of the applied radioactivity in pyrazole and benzamide experiments, respectively. In the pyrazole carbonyl label a polar degradate, 5-bromo-N-methyl-1H-pyrazole-3-carboxamide (2) was present in the filter extracts at an average of 9.5% of the applied radioactivity. The most nonpolar degradate, 2,6-dichloro-4-methyl-11H-pyrido[2,1b]quinazolin-11-one (3), was present in [benzamide carbonyl-(14)C]-treated cigarettes only and represented an average of 14.7% of the applied radioactivity.