Deposition pattern analysis of metal fume particles collected on air sampling filters using micro X-ray fluorescence spectroscopy

Metal-laden aerosols in environmental and occupational settings can pose serious health risks. Accurate exposure assessments are critical to addressing the health risks and require filter-based sampling followed by metal content analysis. However, non-uniform particle deposition on filters can introduce inaccuracies, particularly when using X-ray fluorescence (XRF) for analysis. This study investigates the impact of particle deposition uniformity on XRF analysis across various aerosol samplers. Welding fumes were collected on mixed cellulose ester (MCE) and polyvinyl chloride (PVC) filters using three different samplers. Metal concentrations were analyzed using a micro XRF spectrometer, and deposition patterns were visualized. Results showed that welding fume concentration, filter material, and filter size significantly influenced deposition patterns. Higher fume concentrations led to greater deposition shifts. The study introduced a novel XRF intensity slope analysis method to quantify these shifts. The results indicated significant differences between high and medium concentrations ( p = 0.023) and high and low concentrations ( p = 0.002). MCE filters showed more uniform deposition than PVC filters, and larger filters (37 mm) performed better than smaller filters (25 mm). Field tests confirmed these laboratory findings. This study enhances our understanding of particle deposition and provides valuable insights for improving aerosol sampling techniques and advancing environmental and occupational health standards. • X-ray fluorescence accuracy is affected by uneven particle deposition on filters. • Micro X-ray fluorescence enabled detailed metal and deposition pattern analysis. • Particle deposition shifted based on the air sampling setup and configuration used. • Welding fume levels and filter types strongly influenced deposition distribution. • Mixed cellulose ester and 37 mm filters showed more uniform particle deposition.