P155 Removal efficiencies of solvents by thermodesorber during nanoparticles monitoring of spraying products. (1st September 2016) - Yoo, Danbi
Abstract : Introduction: Various chemicals are used as dispersion solvents in engineered nanomaterials (ENMs)-containing spray consumer products. During use, ENMs are emitted with the solvents into the air. The solvents evaporated during use could cause an interference when the ENMs are monitored. The purpose of this study was to compare the removal efficiencies of solvents by two thermodesorbers during the measurement of ENMs emitted in spraying products use. Methods: One propellant type spray based on ethanol and the other one trigger type based on ethanol and propylene glycol monomethyl ether (PGME) were sprayed in an exposure chamber. A thermodesorber connected to a scanning mobility particle sizer (SMPS) was made up of a heating tube and an absorbent tube (Thermodesorber-1). In addition to thermodesorber-1, a silica gel tube was connected (Thermodesorber-2) and SMPS with no thermodesorber was tested as a control. Organic solvents were sampled with charcoal tubes at the inlets of the thremodesorbers and SMPS and analysed by GC-FID. Results: During the use of propellant spray, the ethanol concentration was reduced greatly according to the thermodesorber use; 1, 180 ppm of ethanol with no thremodesorber was reduced 40.2 ppm with the Thermodesorber-1 and 6.5 ppm with the Thermodesorber-2. Also, the concentration of solvents in trigger type spray with Thermodesorber-1 was decreased about 20 times (14.6 ppm) for ethanol and 17 times (2.0 ppm) for PGME compared to the concentrations measured with no thermodesorber (ethanol; 297.7 ppm, PGME; 34.5 ppm). The concentrations with the Thermodesorber-2 decreased to 7.62 ppm of ethanol and 0.45 ppm of PGME, respectively. The removal efficiency with Thermodesorber-1 was 95% for ethanol and 94% for PGME, while 97% for ethanol and 98% for PGME with Thermodesorber-2. Conclusion: We confirmed solvent removal efficiencies using thermodesober connecting real-time monitor and it showed good efficiencies for each solvent. The thermodesorber could help minimising the interference by solvents during aerosol monitoring. Acknowledgement: This study was sponsored by the fund of National Institute of Environmental Research (NIER-SP2015-254), Republic of Korea in 2015.