Hello All,
The calibration standards were 10, 20, 30, 40, 50, 60, 80 and 100 ng/mL), Concentrations of QC standard were 10 (lower limit of quantification, LLOQ), 30 (QC1), 50 (QC2) and 100 ng/mL (QC3).
Is it correct the selection QCS, or do we need to select concentrations different from calibration standards.
Thank you
For standard calibration carve; you need to prepare same concentration QC sample also, just like calibration standard concentration.
Or take 3 or 4 same concentration point.
Hi Sathish,
What regulations are you validating to? GLP, SANTE or GMP?
It is recommended that QC samples be different to Calibration standards so that you can check your concentrations and preparations. It is also good to have different QC levels so that you can show that Stds/QCs haven’t been swapped giving you further evidence that the method is working correctly.
If this is to GLP standards for validation you will need QC levels at LLOQ level, QC low (2-3x LLOQ level), QC mid (ca 50% of the range, can also add an extra level at the geometric mean), QC high (75-80% of the ULOQ). The acceptance criteria are also important, usually for sample analysis the acceptance would be ±15%.
It depends on the analytes, on the matrices and how the validation study was carried out.
In general the selection of these QCSs is correct and it is possible to choose calibration standard levels as QC levels.
From Guide to Quality in Analytical Chemistry - EURACHEM:
"Standards or materials similar to those used for calibration, placed at intervals in an analytical batch, enable checks to be made that the response of the analytical process to the analyte is stable. It is the responsibility of the laboratory management to set and justify an appropriate level of QC, based on risk assessment, taking into account the reliability of the method, the criticality of the work, and the feasibility of repeating the analysis if the QC sample result is unacceptable."
Here is the link of full text:
https://www.eurachem.org/images/stories/Guides/pdf/Eurachem_CITAC_QAC_2016_EN.pdf
Also, consulting other guidelines (e.g. ICH, SANTE, IUPAC) is a good suggestion.
KRs
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