Environmental Protection Agency (EPA) Lead Risk Assessor Practice Exam

What should be done with the spiked sample when preparing for analysis?

1. Test it immediately

2. Insert it randomly into the sample set

3. Send it as is to the laboratory

4. Discard it after testing

The correct answer is: Insert it randomly into the sample set

In lead risk assessment and environmental testing, spiked samples are crucial for validating the accuracy and precision of analytical methods. When preparing for analysis, spiked samples should be inserted randomly into the sample set. This randomness ensures that the results from the spiked sample are not biased or influenced by position effects that might occur during processing and analysis. By mixing spiked samples within the regular sample batch, you establish an authentic test environment, allowing for a better comparison of results and aiding in the assessment of the method's performance. By not testing it immediately, sending it as is, or discarding it after testing, you risk compromising the integrity and validity of the results. Testing immediately could introduce variability due to time-related factors, while focusing on sending the sample as it is would not allow for any verification of the method's reliability. Discarding the sample after testing disregards the importance of data integrity and traceability in ensuring accurate environmental assessments. Therefore, inserting the spiked sample randomly aids in reliable and effective data analysis and interpretation in lead risk assessment practices.