analyte

An analyte is a substance or chemical constituent in a sample that is the subject of an analysis. It may be a molecule, ion, or compound whose concentration or amount is measured to determine a property such as composition, quality, or health status. In analytical chemistry and related disciplines, the analyte is the target of measurement; results are typically reported as concentration, amount, or activity.

Examples include glucose in blood for diabetes monitoring, lead ions in drinking water for safety assessment, or a pharmaceutical compound in blood to study pharmacokinetics.

Samples contain the analyte together with other components known as the matrix. Matrix effects and other interferents can affect detection, so sample preparation, separation, and selective detection are often required. Calibration with standards allows the instrument response to be translated into an analyte concentration.

Common analytical methods for detecting analytes include spectroscopy, chromatography, mass spectrometry, electrochemical sensing, and immunoassays. The choice of method depends on the chemical properties of the analyte and the required sensitivity and specificity.

Performance characteristics used to evaluate measurements include accuracy, precision, sensitivity, limit of detection, and limit of quantification. Validation typically involves calibration curves, quality controls, and method verification to ensure reliable results.