Analytical Chemistry
The branch of chemistry concerned with identifying substances and determining how much of each is present.
Unit
Dimensionless
In depth
Analytical chemistry divides into qualitative work, which asks what is present, and quantitative work, which asks how much. Modern practice is dominated by instrumental methods, but every one of them ultimately depends on calibration against carefully prepared chemical standards.
Examples in the real world
Testing drinking water for lead, confirming the identity of a synthesised drug, and forensic drug screening.