Trace metal analysis of atmospheric particulate matter: A comparison of personal and ambient samplers

This study compared the size-resolved trace metal concentrations from a standard ambient sampler to those of three commercial personal samplers. Trace metals data from each personal sampler were also inter-compared. Co-located “fixed site” samples were collected in two urban sites in the United States using three types of personal samplers (BGI PM2.5 cyclone, URG PM2.5 cyclone, and Sioutas™ personal cascade impactor sampler [PCIS]) and one standard ambient sampler fitted with a PM2.5 cyclone. This experimental design enabled direct evaluation of the relative performance of the personal samplers. Results of mass measurements showed good agreement between the standard equipment and personal samplers;; however, trace metal comparisons (measured by ICP–MS) showed reproducible concentration biases among personal samplers. These biases can be summarized as BGI < URG < PCIS (0.27 ± 0.08, 0.72 ± 0.08, and 1.32 ± 0.34 relative to the ambient sampler). Elements exhibiting larger variation between personal samplers were associated with higher mass fractions in the coarse fraction, suggesting the PM2.5 size-cut a potential cause of this deviation.