AOAC SPIFAN Nutrients ERP Report (December 7, 2022)

REVIEW OF METHODS: AMINO ACIDS

CODIFICATION: Amino-06 METHOD TITLE: Single Laboratory Validation of Determination of Total Taurine in Infant Formula and Adult/Pediatric Nutritionals by Ultra High-Performance Liquid Chromatography with Multiple Reaction Monitoring Mass Spectrometry REVIEWERS: Estela Kneeteman & Tom Vennard VOTE: Motion - To recommended method for First Action Official Methods SM status Estela Kneeteman motioned Tom Vennard second Vote: 8 Yes/0 No/1 Abstain (FrieslandCampina) RECOMMENDATION: Clarifying points and questions: 1. Adding clarification that water is used to bring flasks to volume. 2. For system suitability, additional detail for the system blank (how is “not detected” defined) and criteria for the method blank and initial 6 injections of the CCV. 3. Clarification of number of calibration standards used. The method describes 8 levels, but also states to use 6 levels. 4. Check T7 Taurine Stock Concentration value. Should this value be changed from 5400 to 5000? 5. Specific safety procedures for TCA are recommended, as this reagent is corrosive and a suspected carcinogen. Questions: o What was the suspected cause for the lower Day 2 results for sample SPIFAN DOMY545? o Why was sample SPIFAN DOMY545 eliminated from the inter-lab study? o Have alternative protein precipitation procedures using less hazardous reagents been evaluated? Motion to approve recommendations: Brendon Gill motioned & Tom Vennard second Abstain – FrieslandCampina ADDITIONAL COMMENTS (AMINO-06): Thank you for the thorough validation work. Here are some editorial comments and questions.  Protein precipitation is achieved by TCA precipitation at 2% TCA final, which is much lower than usually done (typically 12%). Did you try other TCA concentrations? Why did you choose 2%?  H(b) and H(e): with what do you use to fill to the mark? Water? This should be described more precisely  Equation 1: the conversion factors are not fully described. There should be: o ug to mg = 10-3 (top) o mL to L = 10-3 (top) o g (sample) to 100g (sample) = 10-2 (bottom) o FINAL is indeed 1 / (1000 x 10) but in fact it is 100 / (1000 x 1000)  Equation 2: I think “sample” is missing after “Vr Total weight of powder or liquid concentrated sample…”  Table 6: footnotes a and b are redundant  Results, D: LOD: is it powder or reconstituted, also for instance Table 12. As some results are given for reconstituted and some other for powders, it would be good to specify it in each table.