System Suitability Test
Definition
A pre-run check in which a standard mixture is injected into the analytical instrument and key parameters (retention times, peak widths, signal-to-noise ratio, resolution) are verified against acceptance criteria in the method SOP; failure prevents any case analysis from proceeding until the issue is corrected.
- Timing
- Pre-run check before case sample analysis
- Sample used
- Standard mixture with known properties
- Parameters checked
- Retention time, peak width, signal-to-noise, resolution
- Failure consequence
- Case analysis halted until corrected
Common questions
Why does a failed system suitability test stop casework rather than just flagging a warning?+
The test exists to confirm the instrument is performing within the validated parameters the method's results depend on, so proceeding with a case sample on a system that fails suitability risks producing quantitative or qualitative results that cannot be defended as reliable, which is why SOPs typically make it a hard gate.
What kinds of instrument problems does a system suitability failure typically catch?+
Column degradation, detector drift, mobile phase or carrier gas issues, and injector or autosampler faults commonly show up as shifted retention times, broadened peaks, or reduced resolution and signal-to-noise, letting the problem be caught before it contaminates case-sample data.
How does system suitability testing relate to broader method validation?+
Method validation establishes the acceptance criteria once, during development, while system suitability testing re-verifies day-to-day or run-to-run that the instrument still meets those same criteria, functioning as an ongoing quality check rather than a one-time validation exercise.
Related terms
- Certified Reference Material (CRM)
- A sample with one or more analyte concentrations established by an accredited body and traceable to a national metrology institute. NIST SRM...
- Internal Standard (IS)
- A compound chemically near-identical to the analyte, often a deuterated isotopologue (d3-morphine, d5-EDDP, d5-alprazolam, pyrene-d10), spiked into every sample at a known...
- ISO 17034
- The international standard specifying general requirements for the competence of reference material producers; an ISO 17034-accredited producer has demonstrated the technical competence...
- Limit of Detection (LOD)
- The lowest concentration of analyte that produces a signal reliably distinguishable from the instrument noise, conventionally three times the standard deviation of...
- Limit of Quantification (LOQ)
- The smallest concentration that can be quantified with acceptable precision and accuracy, typically corresponding to a signal-to-noise ratio of 10:1 or an...
- Linearity
- The range of analyte concentrations over which an analytical method produces instrument responses that are proportional to concentration (the calibration curve is...
- Measurement Uncertainty (MU)
- A quantified parameter associated with a result that characterises the dispersion of values reasonably attributable to the measurand. Estimated by the GUM...
- Metrological Traceability
- A property of a measurement result whereby the result can be related to a reference (ultimately the SI system of units) through...
- NIST SRM (Standard Reference Material)
- A reference material issued by the US National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, whose property values are established...