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

FOR EXPERT REVIEW PANEL USE ONLY NOT FOR DISTRIBUTION

(11.1% vs 10%). One of the reasons of this discrepancy according to the author can be that this sample was directed to be used pre-diluted, but not all labs executed this protocol. System Suitability 1. Full calibration curves for carnitine and choline were required to have coefficients of determination (r2) of 0.995 or greater and back-calculated concentrations of the calibration standards not exceed ±10% of theoretical.

2. Signal to noise for the low calibration standard was required to be at least 5:1 for each analyte.

3. Solvent blanks and extracted blanks were required to have

Recommendation The method is recommended for the Final action for Determination of Free and Total Carnitine and Choline in Infant Formula and Adult/Pediatric Nutritional Formula. The method did meet the repeatability as well as the reproducibility requirements of the SMPR in all the MLT samples for the analysis of free and total carnitine as well as free and total choline except one sample which provided RSDR value for total choline of 11.1% compared to the SMPR requirements of maximum of 10%.