Analysis of Additive Distributions in Rigid PVC by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) enables direct, spatially resolved analysis of inorganic additives and impurities in rigid PVC, which is widely used in window profiles with demanding lifetime and recycling requirements. This study develops and validates a matrix-adapted LA-ICP-MS protocol for depth-resolved profiling of key additive elements (Ca, Mg, Al, Ti, Zn) and trace Fe in PVC window profiles and laboratory specimens. Laser fluence was optimized, and instrumental precision, positional variability, and ablation depth increments were quantified to ensure reproducible profiles over the first ~25 µm. Subsequently, the method was applied to pressed sheets, extruded belts, and window profiles. The last included samples produced under varying calibration vacuum and those subjected to xenon arc UV/water exposure. Extruded profiles exhibited denser, Zn- and TiO2-enriched, Fe-contaminated skin layers compared with laboratory specimens, while increasing calibration vacuum enhanced near-surface enrichment of several elements. Artificial weathering led to pronounced depth-resolved depletion of Ca, Mg, and Zn in the near-surface region, consistent with stabilizer consumption and leaching of soluble chlorides, whereas Al and Ti remained essentially constant. These results demonstrate that processing strongly shapes near-surface additive and impurity distribution in PVC profiles and that LA-ICP-MS provides a powerful tool to link depth-resolved inorganic composition to aging mechanisms and to assess the transferability of laboratory weathering results to real window profiles.