Temporal variations of volatile organic compounds inside the cabin of a new electric vehicle under different operation modes during winter using proton transfer reaction time-of-flight mass spectrometry

Abstract

Transportation is globally becoming more vehicle-dependent as public awareness towards the health risks caused by cabin-emitted volatile organic compounds (VOCs) increases. Therefore, the need for quantifying their concentration increases as well. This study measured the real-time VOCs in a new mini-truck-type electric vehicle cabin using a proton transfer reaction time-of-flight mass spectrometry under varying cabin heating conditions during winter. A total of 246 ions were detected between m/z 30 and 250, 82 of which were quantified. The total ion count in the cabin was double that of the ambient air. Morning-to-noon concentration of total VOCs increased 2.5 times in the cabin under solar exposure (164.47–405.92 µg·m−3). Additionally, 12 VOCs that either had higher indoor-to-outdoor ratios or globally regulated chosen to investigate the effects of cabin air conditions. Heater operation immediately increased concentrations of some VOCs by 54.62%. Furthermore, blocking solar exposure from windows reduced VOC emissions during heater off and on scenarios by 35.49% and 65.42%, respectively, indicating that window coverage also provided insulation against heat loss. Finally, the fresh air reduced cabin VOCs by 62.83% due to ambient air inflow. However, cabin concentrations remained higher than those of ambient air.