System Suitability Test for Chromatographic Purity

[carlos.teixeira]

Dear Fellows,
It is knew good System Syuitability (SST) for GC or LC should shows CV (RSD) NMT 2% / n = 5 injections. But when we are following one Kinectic of Synthesis Manufacturing Process should be the SST performed with FIVE injections (taking a long time)? Only one or two injections with acceptable Chromatographic Resolution and Theoret. Plates could be enough. Any comments?

Carlos

[tom jupille]

"System suitability test" is whatever it takes for you to be sure that your chromatographic system is functioning suitably for the intended purpose.

2% RSD for 5 injections is commonly accepted for regulatory assays in the pharmaceutical industry (e.g., product purity, potency, content uniformity). It does not necessarily apply in any other context. Depending on the purpose of your analysis, the requirements may be much more strict or much more lenient.

How precisely are you trying to measure or control your process? As a very crude rule of thumb, the uncertainty (RSD) of your measurement should be better than one-third the tolerance of the process. You can get more details on how to relate the RSD and the number of injections to the required confidence interval from any good statistics text.