EDQM FAQs
It is acknowledged that the repeatability requirement of 0.2 % RSD is ambitious; it is nevertheless achievable under normal laboratory conditions. The error on the titre determination has to be limited as the content specifications of titrimetric assays are in most cases set at 100.0 ± 1.0 per cent.
The molarity of the volumetric solutions has to be determined by an appropriate number of titrations. Even if 3 titrations would be sufficient to calculate the RSD it is often better to increase the number of titrations to be able to fulfil the criterion (e.g. n = 6). The RSD criterion is applicable in all cases independently of the titration mode (i.e. automatic or manual) and the type of end-point determination (i.e. electrometric or visual).