Liquid Crystal Display Screens as a Source for Indoor Volatile Organic Compounds
People spend a significant fraction of their lives indoors, and human health can be affected strongly by the cleanliness and chemical content of indoor air. However, indoor air chemistry is complex: volatile organic compounds (VOCs) and other substances can be emitted from a wide range of materials, and chemical reactions involving these VOCs are correspondingly diverse.
In new research from the University of Toronto, researchers explored VOC emissions from liquid crystal display (LCD) screens, and their impact on indoor air quality. Using a Vocus 2R CI-TOF with H3O+ chemical ionization, the researchers discovered more than 30 molecules in air that originated from LCD screens. These VOCs included alkenes and cyclic alkenes, amides, carboxylic acids, and multi-ring cycloalkanes related to liquid crystal monomers. The emission of these VOCs from LCDs was found to be strongly humidity-dependent.
Especially important for this study was the non-targeted analysis capability of the Vocus instrument and Tofware analysis software, and the high time-resolution, that allowed researchers to pinpoint LCD screens as the source of these chemicals and to measure their emission rates. The paper also provides a particularly clear explanation of how chemical structures can be determined, based on the elemental formulas provided by the Vocus instrument.