VOC Emission Screening of Consumer Products in Microchambers: Comparison of Online PTR-MS and Offline TD-GC-MS Analysis

Emissions of volatile organic compounds (VOCs) from consumer products into the indoor air can lead to the inhalation exposure of consumers to potentially hazardous chemicals. This investigation compared two analytical approaches to quantitatively screen VOC emissions from consumer products. A microchamber was used to examine the emissions of two selected products - a rain poncho and a skipping rope - under controlled conditions (temperature, air change rate), with a focus on the initial short-term emissions. Volatiles were sampled from the chamber either on sorbent tubes, with subsequent offline analysis by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS), or with online analysis by proton transfer reaction-mass spectrometry (PTR-MS). The products emitted several compounds of toxicological relevance, including cyclohexanone, xylene, phenol, isophorone, and naphthalene. Data from the two approaches yielded similar emission curves for most compounds, with maximum concentrations observed within 30 min. Isophorone exhibited the highest peaks, with concentrations of ∼1.2 mg m-3 and ∼1.6 mg m-3 from TD-GC-MS and PTR-MS analysis, respectively. Discrepancies in the maximum concentrations between the methods ranged between 25% and 50% for most of the investigated compounds. Total amounts of emitted compounds were calculated as an alternative metric to single concentration values, which allow the assessment of inhalation exposure. This study demonstrates the utility of the two approaches in characterizing short-term VOC emissions from consumer products. PTR-MS analysis offers rapid quantitation of VOCs but has limitations in identifying individual compounds, highlighting the need for complementary analyses by TD-GC-MS. Despite inherent offline sampling, TD-GC-MS was shown to be well-suited to monitoring short-term emissions.