AOAC SPIFAN Nutrients ERP-Final Review (Jan. 2019)

2015.10 (Jan. 2019) Carn-07 MLT Report FOR ERP USE ONLY DO NOT DISTRIBUTE

Conclusion Both the free and total analysis exhibited good repeatability and reproducibility across all matrices within the SMPR scope. Three samples for free choline analysis not within the SMPR scope (<2.0 mg/100g) and produced outlier results at one lab. Two other outliers were found within the study for total choline, and one of these samples was also outside of the proposed working range of the method. In conclusion, all but 1 sample result set met SMPR requirements for both free and total carnitine and choline. The one exception was reproducibility for the adult nutritional ready to feed-high fat sample for total choline that was just above the requirement (11.1% vs 10%). This sample was directed to be pre- diluted, but not all labs executed this detail of the procedure including the two labs reporting the lowest values by far (5 and 9). These data shows that the method procedures are fit for purpose for the determination of both free and total carnitine and choline in a wide variety of infant formula and adult nutritional samples. There was increased variability for total choline compared to other analytes, but this is within expectation for a large MLT trial requiring intensive microwave digestion of samples and employing LCMS triple quadrupole analysis.

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