BS ISO 21470:2020 pdf free.Infant formula and adult nutritionals一 Simultaneous determination of total vitamins B1, B2, B3 and B6一Enzymatic digestion and LC-MS/MS.
BS ISO 21470 adult nutritional nutritionally complete, specially formulated food, consumed in liquid form, which may constitute the sole source of nourishment, made from any combination of milk, soy, rice, whey, hydrolysed protein,  starch and amino acids, with and without intact protein.breast-milk substitute specially manufactured to satisfy, by itself, the nutritional requirements of infants during the first months of life up to the introduction of appropriate complementary feeding Samples are prepared by enzymatic digestion with papain and a-amylase to hydrolyse protein and complex carbohydrate and acid phosphatase to free phosphorylated vitamin forms. Stable-isotope labelled internal standards are incorporated into the sample preparation to correct for variability in both the sample preparation and instrument response. A series of six mixed working standard solutions spanning two orders of magnitude in vitamin concentration are used to generate calibration curves based on the peak response ratio of the analyte to its stable-isotope labelled internal standard. Prepared samples and working standard solutions are injected onto ultra-high pressure liquid chromatograph (UPLC) interfaced to a triple-quadrupole mass spectrometer (MS/MS) for analysis. The MS/MS is configured to monitor precursor-fragment ion pairs for each analyte and internal standard. This reaction forms the basis for method selectivity. Analytes are quantified by least squares regression
using the response ratio of the analyte to its internal standard.Internal standard stock solutions have an expiration of six months. However, the following guidelines can be used to troubleshoot internal standards and, when documented as part of routine system suitability checks, extend the expiration dates indefinitely. Based on US FDA bioanalytical method validation guidelines, which state that the lowest-level calibration shall be five times the analyte response of the blank,[9] the channel of the non-labelled analyte of interest shall be monitored to ensure the stable isotope-labelled internal standard does not contribute more than 20 % of the area count of the lowest-level calibration standard. No response should
be generated in any other channels being monitored in the method, as this is a sign of contamination, in which case fresh solution should be prepared or fresh lot of material should be ordered.The area count of the internal standard should be at least three times the area count of the analyte in the lowest-level calibration standard and the lowest level matrix-based QC sample.BS ISO 21470 pdf download.