A new device for the simulation of indoor air pollution sources

A reliable and flexible generation system for volatile organic compounds is a valuable tool for indoor air researchers, for instance, in the context of investigations on interactions between organic vapors and indoor materials. A new VOC vapor generation system has been developed and tested for its applicability in indoor air research. it is based on a modified droplet ejector working on the principle of a piezoceramic ink-jet printer. Different solutions, consisting of complex mixtures of compounds, were used for performance testing of the system. The compounds covered a wide boiling point range and included lipophilic and hydrophilic substances. Emission rates have been generated in the range from 8 mu g/h up to 7.7 mg/h per compound, simulating indoor emission sources from low to high emission potential. Emission rates monitored over >90 h showed relative standard deviations <2% for most compounds, being close to analytical uncertainties. The system shows a very high flexibility with regard to number and choice of compounds to be evaporated, their relative concentrations, the total emission rate, down to indoor relevant values, and together with good emission constancy and high precision allows for numerous applications.