US EPA Model Lead Inspector Practice Test

Spiked samples are used to check a laboratory’s analytical performance by adding a known amount of lead to a dust wipe matrix. The lab then processes this sample just like a real one, and the measured lead is compared to the known value. This QA step shows how accurate and precise the lab’s methods are, how well recovery and extraction work, and whether the instrumentation and procedures are giving trustworthy results for dust wipe samples. The other ideas—humidity in the testing environment, the age of the dust, or the effectiveness of PPE—aren’t evaluated through spiked samples, which focus on the lab’s ability to analyze the contaminant in the sample.