What does the term "adulterated" mean in the context of drug testing?

In the context of drug testing, the term "adulterated" refers specifically to a specimen that has been tampered with in order to alter the test results. This can involve the addition of substances that mask the presence of drugs or other alterations that would make the sample unreliable for testing. Adulteration methods are typically employed by individuals attempting to evade detection of illicit substances. Such tampering undermines the integrity of the testing process and is a serious concern in drug screening protocols.

The other options describe different issues with drug specimens but do not capture the specific meaning of "adulterated." For instance, a specimen exceeding the acceptable temperature range indicates that it may not be a valid sample due to potential manipulation, but it does not imply active tampering in the sense defined by adulteration. Similarly, an unusually high concentration of drugs or incorrect processing relates to the quality or validity of the sample but do not inherently imply intentional tampering. Thus, the correct interpretation of "adulterated" directly ties back to the act of intentionally modifying a sample to influence the outcomes of drug testing.