GC-IMS Assessment of Odor Fingerprints and Scrubber Efficiency in a Multi-Floor Swine Building

Intensive swine production has elevated concerns regarding malodorous emissions, whose high complexity poses substantial challenges for deodorization assessment. This study conducted a multidimensional evaluation of a dual-stage scrubbing system in a multi-floor swine facility using gas chromatography–ion mobility spectrometry (GC-IMS). By establishing volatile compound fingerprints, we quantified the shifts in 29 individual constituents before and after treatment. The GC-IMS results were further validated through comparative analysis with infrared photoacoustic spectroscopy (PAS) and sensory olfactometry. Results from multivariate statistical analysis (PCA) successfully differentiated the removal efficiencies of various components. Notably, GC-IMS revealed an apparent increase in the signal intensities of certain compounds, which might be overlooked by traditional analytical methods. While NH3 removal efficiency measured by GC-IMS (79.86% with semi-quantitative analysis) was in high agreement with PAS results (77.89%), sensory olfactometry showed a non-significant reduction (p = 0.1571). Although GC-IMS provides a rapid platform for screening volatile compounds and tracking dynamic shifts during the deodorization process, detecting certain key swine malodor components requires further optimization. Ultimately, future methodological integration of GC-IMS, GC-MS, and olfactometry is essential to establish a field-validated evaluation framework for swine odor monitoring and deodorization efficiency assessment.