Paper-Based Filter Membrane for High-Efficient Sampling and Direct Mass Spectrometric Analysis of Siloxanes in Outdoor Air

Abstract Siloxanes have been found widespread usages in our daily lives, but the knowledge on their migration, transformation and toxicity is still limited. Herein we explored the feasibility of using one-sided silica coated paper as filter membrane to capture siloxanes in the outdoor air, followed by direct mass spectrometric analysis. In contrast to mostly utilized fiber membrane, silica coated paper not only exhibited a higher selective sampling efficiency to three siloxanes with structures of H–[Si(CH3)2–O]7-9-NH2 from air, but also possessed a high tolerance to organic solvent during mass spectrometric analysis. Due to the above features, the analysis sensitivity of those siloxanes with silica coated paper has been improved 3.1–134.8 folds in contrast to those with commercial filter membrane. Furthermore, we monitored variation in the levels of those siloxanes for a period of one month, and found that a close association (R2 = 0.7924–0.9559) existed between their contents and climate parameters (e.g., temperature, weather, atmospheric pressure, humidity, wind direction and wind speed) as well as sampling volume. These knowledge provides a facile and effective methodology to both high-efficient sampling siloxanes and environmental assessment of siloxanes according to climate parameters.