BS ISO 23293:2020 pdf free.Milk-based infant formula powders—Quantification of whey protein content by sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE).
BS ISO 23293 Automatically integrate the electropherograms from the valley located at 0,5 min to 1 min before the 10 kDa internal protein standard peak (include any peak immediately adjacent to the 10 kDa internal  protein standard) to the valley between the end of K-casein peak and the peak of Ig H and BSA (no negative peaks should be generated by the integration). Then, perform a manual integration from the valley before the peak of Ig H and BSA until the end of the last peak in the electropherogram (integrate all peaks including those after the peak of Ig H and BSA if present). Examples of electropherograms including the automated and manual integration regions are given in Figures A.2 and A.3 for SMP and  infant formulas, respectively. Examples of integration parameters are listed in Table A.1.Test the system suitability using the 10 kDa internal protein standard (5.6) and the SDS-MW size standard (5.7). Define the migration time of the 10 kDa internal protein standard for each combination of instrument, capillary and reagents beforehand. The acceptance criteria for the system suitability are as follows.Interlaboratory tests were conducted in accordance with ISO 5725-1 and ISO 5725-2. The repeatability and reproducibility values for 14 cow milk-based infant formulas with a whey protein content of  40 % or more and one reference standard for infant/adult nutritional formula with a whey protein content below 40 % have been published[7]. The performance values for the SMP sample that had been systematically used as a quality control during the same study were subsequently extracted. The values from the SMP and the reference standard samples were used to evaluate method performance in infant formulas with a whey protein content below 40 %. The values derived from these trials might not be applicable to concentration ranges and matrices other than those given. In particular, this method is not applicable to infant formulas produced from milk originating from species other than cow, from plant proteins or from hydrolyzed proteins.BS ISO 23293 pdf download.