Aerosol Time-of-Flight Mass Spectrometry
ATOFMS instruments perform real-time measurements of aerodynamic diameter and chemical composition of ambient particles.
Brief Development Timeline:
1st generation (1992): “The Beast” is a stationary laboratory single-polarity instrument used for instrument development. The Beast currently resides with former Prather group member Prof. Ryan Moffet at University of the Pacific
2nd generation (1997) "Jake" and "Elwood" are field transportable, dual-polarity instruments. Jake is configured with an aerodynamic lens for detection of ultrafine particles (UF-ATOFMS) from 80-1000 nm.
3rd generation (1999) “Laverne” is also field transportable and dual-polarity and was the prototype for TSI’s commercial ATOFMS instrument, (Model 3800) and with aerodynamic lens for detection of particles from 30-1000 nm (Model 3800-030).
4th generation (2005) "Shirley" is an aircraft-ATOFMS that incorporates improvements in size and peformance that allow us to probe the particles seeding mixed phase clouds. Shirley has flown on the DOE G1 and NCAR C130.
A chemical ionization version of the ATOFMS ("Clifford") is currently under development.
Just a few studies that ATOFMS has been a part of:
ICE-L, CARES, CalNex, PRADACS 2010-2011, CalWater 2011, INDOEX, ACE-Asia, CalCOFI, CARES, IMPACTS, FIN1, CalWater 2015
Ongoing instrument development and data analysis projects:
Procedures for quantification and scaling detected ATOFMS particle types to atmospheric concentrations
Source apportionment of ambient particles, i.e. comparison of emission mass spectral "fingerprints" to atmospheric particle measurements
Data from ATOFMS are being used as inputs to improve atmospheric chemistry and climate models
Detection of bioaerosols by ATOFMS has been performed for the and health effects studies