What does qualitative testing determine?

Qualitative testing is a method used to determine whether a particular substance is present or absent in a sample. It does not provide information on the quantity or concentration of the substance, but rather confirms its existence. This type of testing is crucial in various fields, including medicine and toxicology, where quick determinations of drug presence can be critical for diagnosis, treatment decisions, or legal matters.

In contrast, other types of testing focus on different aspects, such as quantitative testing which determines the exact amount of a substance, or specificity testing that identifies the particular type of drug. Therefore, the option that indicates that qualitative testing assesses the presence or absence of a drug accurately reflects its primary purpose in laboratory settings.