by
Tim » Thu Jul 07, 2005 12:26 pm
I've just checked and the way we compared between the CDSs was to run the exact same samples, with same mobile phase/column, etc. on both systems. If you can also use the same HPLC, that is even better, because then only the CDS will have changed. We were fortunate when we changed CDS in that the old system just used an A/D convertor on the analogue output of the detector, while the new one used a digital output (it was ChemStation), so we got EXACTLY the same chromatography going into both systems.
Using the response factors from CDS1 for the two samples generated, we calculated +/-2% limits and verified that the response factors (Amount) generated by CDS2 were within these limits for the respective samples, for the peaks of interest.
For the Efficiency, Tailing Factor and Resolution for the first standard and first sample generated by CDS1, we calculated +/-5% limits for each peak of interest. We then verified that the values generated by CDS2 lay within these limits.
We also compared the output from both systems against the standard acceptance criteria for the method, e.g. Efficiency greater than 2000, RSD <=2%, etc.