Field calibration of nitrogen-doped carbon-coated silicon carbide (NMC@SiC) passive air samplers to measure polar and non-polar semi-volatile organic compounds

Abstract

This study reports the first field calibration of nitrogen-doped carbon-coated silicon carbide (NMC@SiC) passive air samplers for measuring semi-volatile organic compounds (SVOCs) in the atmosphere of the Alsace region. The NMC@SiC samplers were deployed concurrently with conventional low-volume active samplers at a central urban site in Strasbourg, enabling direct comparison between passive and active sampling techniques. Sampling covered five two-week periods (2018–2019) plus extended three-to-four-week deployments (2019–2020). After exposure, target compounds adsorbed onto the sorbent were extracted using a two-step protocol involving accelerated solvent extraction followed by solid-phase extraction. Analytical quantification was performed via gas chromatography-mass spectrometry (GC-MS), gas chromatography-tandem mass spectrometry (GC-MS/MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS), ensuring robust compound-specific detection and quantification. NMC@SiC samplers effectively captured a broad spectrum of SVOCs, including PAHs, PCBs, organochlorine pesticides (OCPs), phenols, and organic acids. Mean sampling rates (R_s) ranged from 2.5 and 6.0 m³ day⁻¹, values comparable to or slightly exceeding those of established passive samplers. Importantly, NMC@SiC efficiently collected both highly semi-volatile and polar analytes (like phenols and carboxylic acids), underscoring its suitability for legacy and emerging pollutants. Its high surface area and polar coating facilitate uptake of both nonpolar and polar compounds, highlighting its promise as a robust tool for long-term SVOC air monitoring. This pioneering field deployment demonstrates NMC@SiC’s potential as a next-generation passive sampler for comprehensive air quality assessment.