What is Reagent?

• A. A substance added to a system to bring about a chemical reaction.
• B. The non-analyte portion of a sample.
• C. The test instrument.
• D. The sample container.

Answer: (A)

Reagent is a substance added to a system to bring about a chemical reaction. In analysis, reagents react with the analyte or create conditions that allow the reaction to proceed, producing a measurable signal or change. This distinguishes reagents from other elements: the non-analyte portion of a sample is the matrix, the test instrument is the device that measures, and the sample container is just the vessel that holds the sample. So the idea that a reagent is something intentionally added to drive a chemical reaction is the best description.