AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
On-Line Aerosol Characterization within Exposure Systems Using Soft Ionization Time of Flight Mass Spectroscopy
Sandro Steiner, Shoaib Majeed, ARKADIUSZ KUCZAJ, Stefan Frentzel, Julia Hoeng, Philip Morris Products S.A., Switzerland
Abstract Number: 269 Working Group: Aerosol Exposure
Abstract Three dimensional organotypic models of the human respiratory tract epithelia are the most advanced biological test systems in in-vitro inhalation toxicology. They enable the exposures to be conducted with the cell cultures in direct contact with the test atmospheres, i.e., at the air-liquid interface. As the test atmosphere may change its physicochemical properties within aerosol exposure systems (e.g., due to dilution and liquid-vapor partitioning), methods for monitoring chemical aerosol composition in close proximity to the exposure chambers are required.
We present a method using soft photon ionization time-of-flight mass spectroscopy (SPI-TOFMS) to measure the chemical composition of test aerosols in real-time within the Vitrocell 24/48 aerosol exposure system (Vitrocell GmbH, Germany). The SPI-TOFMS (Photonion GmbH, Germany) was connected to the Vitrocell system one centimeter upstream from the quartz crystal microbalance chamber, which is structurally and functionally equivalent to sampling directly upstream to the cell culture exposure chambers. Cigarette smoke (3R4F research cigarettes) and aerosols representative of commercially available electronic cigarettes (generated in a collision nebulizer) were delivered to the system as during regular exposures of organotypic tissue cultures, and mass spectra were acquired continuously.
The applicability of the method is demonstrated via reproducible high-resolution monitoring of the chemical composition of the smoke/aerosol and its time-profile (the puffing). Furthermore, the quantification of representative constituents was in agreement with extrapolated results of established off-line methods, indicating that non-representative aerosol sampling and co-localization of mass peaks of different compounds or their fragments does not pose a major limitation of the proposed measurement method.