Definition
The threshold at or above which the laboratory will report a numeric value for a given analyte on a given method. It is stated on the certificate so that a "not detected" result carries a number a reader can evaluate.
"Not detected" never means "none present". It means none present above the stated reporting limit under the method used.
Related terms
About quantitation and content
How much is actually there, on what basis, and against what standard.
Peptide contentLabel claimPeptide base versus gross saltCounter-ionResidual moistureReference standardCalibration curveLinearityWorking rangeRecoveryLimit of detectionMeasurement uncertaintyMatrix effect