9.16 Determining Amount of Controlled Substance is the process of determining the amount of an illegal psychoactive substance, such as a narcotic drug or a controlled substance. This process is used by law enforcement agencies to detect and prosecute drug-related offenses. It involves measuring the amount of the drug found on a person or in a location as well as analyzing the drug’s chemical composition. Different types of 9.16 Determining Amount of Controlled Substance include chemical analysis, weighing, and spectroscopy. Chemical analysis is a method of analyzing a substance to confirm the identity and amount of a particular drug present. Weighing is a process of measuring the mass of an object, such as a drug, to determine the amount. Spectroscopy is a method of analyzing chemicals in a sample and identifying their components.