A triple quadrupole mass spectrometer system for studies of gas-phase combustion chemistry of energetic materials

A triple quadrupole mass spectrometer (TQMS) system utilizing the collision-induced dissociation process has been constructed for studies of gas-phase combustion chemistry of energetic materials under various conditions of pressure and incident laser heat flux. A unique feature of the TQMS system is its capability to differentiate species at the same mass-to-charge (m/z) value and to identify chemical structures of the gaseous species evolved from the energetic materials, through the recognition of the fragmentation characteristics of chemical functional groups in species. Two different settings for high and low collision energy modes were developed for the daughter mode of operation. A calibration method at the two settings in the daughter mode was also developed for the quantification of the measured species. The TQMS system developed also includes integrated vacuum system, quartz microprobes for gas species sampling, customized software for data acquisition and data reduction. Typical results are presented to illustrate the methods used to differentiate the measured species and to identify their chemical structures.