What test measures the purity of a chemical?

What test measures the purity of a chemical?

• A. Purity
• B. Bioassay
• C. United States Pharmacopeia
• D. Assay

Answer: (D)

Purity is about how much of the desired substance is present relative to impurities. The test that quantifies a substance's amount (and by extension its purity) is an assay. An assay provides a numerical value for the substance’s content and can reveal impurities, making it the method used to determine purity in chemical and pharmaceutical contexts. Purity by itself isn’t a test. A bioassay measures biological effects rather than chemical cleanliness. The United States Pharmacopeia is a standards compendium, not a testing method. An assay, specifically, is the procedure used to measure how much of the chemical is present and, thus, its purity.

Purity is about how much of the desired substance is present relative to impurities. The test that quantifies a substance's amount (and by extension its purity) is an assay. An assay provides a numerical value for the substance’s content and can reveal impurities, making it the method used to determine purity in chemical and pharmaceutical contexts.

Purity by itself isn’t a test. A bioassay measures biological effects rather than chemical cleanliness. The United States Pharmacopeia is a standards compendium, not a testing method. An assay, specifically, is the procedure used to measure how much of the chemical is present and, thus, its purity.