Accuracy
Closeness of agreement between a measured value and a true quantity value; often discussed through components such as trueness and precision.
Working definition; see JCGM and Eurachem references above.
REFERENCE DESK
Analytical glossary.
Concise working definitions. Context and field-specific standards may refine how each term is used.
Definition basis
These editorial working definitions are paraphrased from established metrology and analytical-method vocabulary. Consult the current governing standard for formal or field-specific use.
Analyte
The component or quantity intended to be measured.
Working definition; see JCGM and Eurachem references above.
Bias
An estimate of systematic measurement error.
Working definition; see JCGM and Eurachem references above.
Chain of custody
The documented history of sample possession, transfer, handling, and storage.
Working definition; see JCGM and Eurachem references above.
Matrix
All components of a sample other than the analyte, which may influence measurement.
Working definition; see JCGM and Eurachem references above.
Measurement uncertainty
A parameter describing the dispersion of values that could reasonably be attributed to the measurand.
Working definition; see JCGM and Eurachem references above.
Precision
Closeness of agreement among replicate measured values under specified conditions.
Working definition; see JCGM and Eurachem references above.
Reporting limit
A laboratory- or program-defined level at or above which a result is reported quantitatively under stated criteria.
Working definition; see JCGM and Eurachem references above.
Selectivity
The extent to which a method can determine an analyte in the presence of expected interferences.
Working definition; see JCGM and Eurachem references above.
Traceability
A property linking a result to a reference through a documented, unbroken chain of calibrations, each contributing uncertainty.
Working definition; see JCGM and Eurachem references above.