Non-targeted analysis of unknown volatile substances in plastic toys using GC-Orbitrap high-resolution mass...

Given the widespread use of plastic toys and their close contact with children, identifying odorants and associated chemical risks is crucial. This study employed GC-Orbitrap high-resolution mass spectrometry for non-targeted screening, identifying 216 volatile substances in 56 plastic toys. Orthogonal partial least squares discriminant analysis (OPLS-DA) revealed 22 significantly different substances, while characteristic compounds for ABS, PVC, and TPR materials were identified via clustering heatmap and Venn diagram analysis. Among the volatiles, 40 have odor descriptions, with 33 having known odor thresholds. Analysis of odorant distribution and contribution identified isophorone, propylbenzene, ethylbenzene, and xylene as the dominant odorants. A risk prioritization scheme, based on detection rate, average peak area, and hazardousness, enabled the rapid identification of 16 high-risk substances. The quantification confirmed that diisobutyl phthalate levels in five PVC and one TPR toy surpassed the 0.1 % threshold. Several other compounds, namely naphthalene, isopropylbenzene, 4-vinylcyclohexene, α-methylstyrene, and methyl methacrylate, also posed a concern. Correlation analysis indicated that certain high-risk substances co-occurred and showed consistent concentration trends, likely due to shared raw materials or processes. This study provides valuable insights for odor tracing and the precise control of chemical risks in toys and related products.