ABC-BIO key terms

The quantitative measurement of drugs, metabolites, or biomarkers in biological matrices such as plasma, serum, urine, or tissue, typically to support drug development, toxicology, or clinical decisions.

The complex sample material of biological origin in which an analyte is measured, for example plasma, serum, urine, blood, tissue, or saliva. Its composition strongly influences extraction and detection.

The specific chemical or biological substance that an analytical method is designed to detect and quantify in a sample.

A compound added in known amount to every sample and standard to correct for variability in sample preparation, injection volume, and detector response. Stable-isotope-labeled analogs are common in bioanalysis.

A plot of detector response versus known analyte concentration, generated from standards, used to relate measured signal to unknown sample concentration over a defined range.

The lowest analyte concentration or amount that can be reliably distinguished from background noise, usually estimated at a signal-to-noise ratio of about three.

The lowest analyte concentration that can be measured with acceptable accuracy and precision, typically the lowest calibration standard meeting defined criteria.

The closeness of a measured value to the true or accepted reference value, often expressed as percent bias or percent recovery.

The degree of agreement among repeated measurements of the same sample under specified conditions, commonly reported as percent coefficient of variation.

Precision obtained when the same analyst measures the same sample multiple times within a short interval using the same instrument and conditions.

Precision measured across changed conditions within one laboratory, such as different days, analysts, or equipment, reflecting routine method robustness.

The ability of a method to measure an analyte accurately in the presence of other sample components, including metabolites, impurities, and matrix constituents.

The ability of a method to respond only to the intended analyte and not to structurally related compounds or other sample components.

The change in detector response caused by co-eluting components of the sample matrix, which can suppress or enhance ionization or signal relative to a pure standard.

A reduction in ionization efficiency in mass spectrometry caused by co-eluting matrix components competing for charge, leading to lower signal for the analyte.

The proportion of analyte successfully carried through sample preparation and detected relative to the amount originally present in the sample.

The steps taken to isolate, concentrate, and clean up an analyte from a biological matrix before analysis, such as protein precipitation, extraction, or dilution.

A sample cleanup technique in which an organic solvent, acid, or salt is added to biological fluid to denature and remove proteins, releasing the analyte into the supernatant.

A sample preparation technique that partitions an analyte between two immiscible liquid phases based on differing solubility, allowing separation from matrix components.

A sample preparation technique in which analytes bind to a solid sorbent and are eluted selectively with solvent, enabling concentration and removal of interfering matrix components.

The general process of separating an analyte from its sample matrix into a different phase or solvent to enable cleaner, more sensitive measurement.

A separation technique in which components of a mixture distribute differently between a mobile phase and a stationary phase, causing them to elute at different times.

The time elapsed between sample injection and the maximum detector response for a given analyte under defined chromatographic conditions, used for identification.

A measure of how well two adjacent chromatographic peaks are separated, calculated from their retention times and peak widths.

A measure of chromatographic column efficiency describing the number of equilibration steps, where more plates and smaller plate height indicate sharper peaks.

The liquid or gas that carries the sample through the chromatographic system and past the stationary phase.

The immobile packing or coating in a chromatographic column that interacts with sample components to produce differential retention.

An analytical technique that ionizes molecules, separates ions by mass-to-charge ratio, and detects them, providing sensitive and specific detection for bioanalysis.

A soft ionization technique that generates ions from a liquid sample by applying high voltage to a sprayed aerosol, commonly coupled with liquid chromatography.

A mass spectrometry acquisition mode that monitors a specific precursor-to-product ion transition, giving high selectivity and sensitivity for targeted quantitative analysis.

A separation technique using a liquid mobile phase pumped through a packed column, widely coupled with mass spectrometry for quantitative bioanalysis.

The documented process of demonstrating that an analytical method is suitable for its intended purpose by evaluating parameters such as accuracy, precision, selectivity, and stability.

The extent to which an analyte retains its measured concentration under defined storage and handling conditions, including freeze-thaw, bench-top, and long-term storage.

Any component of the sample, reagents, or system that produces a signal or alters the response of the analyte, reducing method accuracy.

The ratio of analyte signal to background noise, used to judge detectability and to estimate detection and quantification limits.

The ability of a method to detect small changes or low concentrations of analyte, often reflected by the slope of the calibration curve.

A sample of known analyte concentration analyzed alongside unknowns to verify that a batch meets predefined accuracy and precision criteria.

The transfer of residual analyte from a previous sample into a subsequent one within the analytical system, which can falsely elevate low-concentration results.