Development of a Chemical Ionization Time-of-flight Mass Spectrometer for Characterizing the Role of Organic Amines in New Particle Formation

Aerosol particles are known to affect the global climate through cloud formation. Globally, it is believed that ~50% of cloud condensation nuclei (CCN) originate from atmospheric new particle formation and growth. Sulfuric acid vapor plays a key role in new particle formation, although detailed mechanisms remain unclear. Recent experiments have shown that trace levels of organic amine vapors can enhance particle nucleation by 1000 times or more compared to sulfuric acid alone or sulfuric acid plus ammonia. Amine vapor concentrations are typically very low and at the detection limit of current measurement techniques. The evaluation of atmospheric nucleation rates and particle growth is limited by sparse amine vapor measurements and the resulting lack of knowledge of atmospheric amine budgets. The proposed use of amines for CO2 sequestration may increase ambient amine concentrations and has significant implications for aerosol CCN budgets and their cloud interactions. This SBIR project will develop a mass spectrometer for the detection of ambient amines with a factor of 10 to 1000 times better sensitivity than current instruments, in order to improve characterization of global amine budgets and our understanding of their role in aerosol formation. Aerodyne Research, Inc. will develop and test a new chemical ionization mass spectrometer that employs bisulfate ion chemistry for the selective and quantitative detection of amines. Specific tasks during Phase I include characterization of the operational parameters that affect ion source performance, calibration of the system for a broad range of amines, experiments at an environmental reaction chamber to demonstrate the instruments potential for exploring the role of amines in the formation and growth of atmospheric aerosols, development of custom data analysis software routines, and designing the prototype to be constructed in Phase II. Commercial Applications and Other Benefits: The initial market for this instrument will be atmospheric research groups at universities and national laboratories, including DoE facilities. We expect that the system developed in this program will yield a significant level of direct commercial sales and contract field measurements from the atmospheric science research and development community.