The following question and answer were taken from LCGC Europe's "CE Currents" column (1).
The following question and answer were taken from LCGC Europe’s “CE Currents” column (1).
What do I need to cover during CE method validation?
This largely depends on the final optimized diluent that is included in the method. For example, if the final method states 5 mM phosphate pH 2.3 as the diluent — it may be appropriate to assess diluent in the range 4–6 mM and pH 2.1–2.5 to gain confidence in performance and allow some flexibility during sample diluent preparation. System suitability samples should be run prepared in diluents covering the ranges being assessed. Once the limits have been scientifically proven to be acceptable then they can be included in the method, for example, to prepare samples in 4–6 mM phosphate at pH 2.1–2.5.
Robustness experiments should be conducted using appropriate samples and standards to test the impact of diluent composition variations and to determine operating limits.
Attention to sample stability in the optimized dissolving solvent would need to be tested to experimentally determine a shelf-life for samples.
(1) K. Altria, LCGC Europe, April 2008.