A project manager tasked with determining the concentration of metals in ambient air at an environmental site faces several important challenges: 1) Metals in ambient air are typically present in trace concentrations; 2) Current analytical methods have detection limits for some metals that are considerably above regulatory screening levels; and 3) Filter media can have significant background levels of target metals. This paper compares two analytical methods on their ability to address these challenges: 1) ICP/MS analysis of quartz fiber filters collected with a high volume air sampler; and 2) XRF analysis of Teflon® filters collected with a low volume air sampler.