Optical properties of gaseous 2,4,6-trinitrotoluene in the ultraviolet region

The absorption spectrum of gaseous 2,4,6-trinitrotoluene (TNT) was recorded by conventional absorption spectroscopy (AS) as well as cavity ringdown sp ectroscopy (CRDS) methods in the spectral regions 195-300 and 225-235 nm, r espectively, These spectra were normalized by using the saturated TNT vapor -number density for the measured cell temperature to obtain the absorption cross section of TNT. No spectral features were found in the spectra; this result is consistent with a repulsive electronic excited state of TNT. The temperature dependence of the absorption coefficient of saturated TNT vapor was measured within the temperature range 5-110 degreesC. The limit of det ection of TNT vapor by CRDS is less than 1 ppb. Real-time CRDS measurements of the TNT vapor density at 21 and 37 degreesC are presented. The TNT evap oration rates were found to be 7 x 10(8) and 4 x 10(10) molecules/cm(2) x s at 21 and 37 degreesC, respectively.