Further Revision of Ph. Eur. General Chapter 2.2.46 Concerning Signal-to-Noise Ratio

Recommendation
24 November 2025
Neuss, Germany
Part of PharmaLab Congress 2025
As already reported a few months ago, a revised general chapter 2.2.46. Chromatographic separation techniques has been published in Ph. Eur. 11.0. The implementation date is 01 January 2023.
One of the changes is the sensitivity requirement. According to the revised chapter, the signal-to-noise (S/N) ratio is calculated on a window of 20 times the peak width at half height (“20 x Wh”). In contrast, from Ph. Eur. Supplement 6.4 through Supplement 10.8, the S/N ratio is calculated on a window of at least 5 times the peak width at half height (“at least 5 x Wh”).
In this context, the EDQM has now published a press release dated 14 December 2022, stating that this change might be technically challenging for a number of users. Therefore, there will be another revision, which will be included in Supplement 11.3 (to be published in July 2023 and implemented on 01 January 2024).
The EDQM writes that in the meantime "Ph. Eur. users are advised to continue calculating the S/N ratio on a window “at least 5 x Wh”, instead of “20 x Wh”."
Please also see the supporting information in the EDQM knowledge database.
Related GMP News
13.11.2025Proposed Revision of USP <1225> Published in the Pharmacopeial Forum
13.11.2025Recent Publications Highlighting Topics to be Discussed at PharmaLab 2025
12.11.2025USP seeks early Input on new NMR Method
12.11.2025FDA Warning Letter: Several Analytical Deficiencies Identified at Chinese Manufacturer


