Analytical quality
How to Challenge an Analytical Method's Selectivity
Analytical selectivity: Does the signal distinguish the analyte from plausible interferents?
Source editorial review:
Before interpreting the result
Does the signal distinguish the analyte from plausible interferents?
- Name the analyte, matrix and interferents relevant to the intended use.
- Review blanks, spiked samples and related components.
- Separate demonstrated selectivity from an assumption that a signal is specific.
Analytical selectivity
A selective method must distinguish the intended measurement from interferences relevant to its use. A clean signal in a simple reference does not establish equal performance in a complex sample. Matrix, impurities and transformation products can challenge that capability differently. Selectivity is documented against specific scenarios, not an instrument's reputation.
A reading case: what to check
Judge a measurement by asking which interferences were assessed and which could occur in the sample. If matrix or formulation changed, reconsider whether the available validation remains relevant. A result can be correct within the studied scope while requiring additional evaluation for another use. Keep both facts explicit.
What to preserve in the record
Selectivity belongs to a defined application. Validation in another matrix or against another family of interferents does not automatically cover the current sample.
Questions and answers
Does the signal distinguish the analyte from plausible interferents?
A selective method must distinguish the intended measurement from interferences relevant to its use. A clean signal in a simple reference does not establish equal performance in a complex sample. Matrix, impurities and transformation products can challenge that capability differently. Selectivity is documented against specific scenarios, not an instrument's reputation.
What should the review record preserve?
Selectivity belongs to a defined application. Validation in another matrix or against another family of interferents does not automatically cover the current sample.