Environmental Protection Agency (EPA) Lead Risk Assessor Practice Exam

What is the purpose of spike samples?

1. To evaluate laboratory costs

2. To identify contamination sources

3. To assess the accuracy of analytical methods

4. To speed up the sampling process

The correct answer is: To assess the accuracy of analytical methods

The purpose of spike samples is to assess the accuracy of analytical methods. Spike samples are created by adding a known quantity of a substance (such as lead) to a sample matrix before analysis. This allows for the evaluation of the laboratory's ability to measure the added substance accurately. By comparing the known quantity of the spike with the quantity detected in the analysis, laboratories can ascertain the method's recovery rate and accuracy, providing critical insights into the reliability of the data produced. In environmental assessments, understanding how well an analytical method can detect and quantify lead is essential, especially when it comes to ensuring public health and safety. Accurate measurement is particularly vital in lead risk assessment, as incorrect data could lead to inadequate risk management or remediation strategies.