Abstract
The performance of colocated filter pack and denuder samplers in measuring atmospheric sulfate, nitrate, chloride, and ammonium species was compared. The amount of a species collected by the two sampling systems was almost the same, although there was evidence for superior inlet efficiency for particles in the filter pack. The filter pack yielded slightly higher measurements of the volatile species nitric acid, hydrochloric acid, and ammonia than did the denuder, with a corresponding lower measure of particulate nitrate, chlorine, and ammonium. The divergences between the two techniques are small, and differences in measurement are considered to be site-, operator-, and apparatus-specific.