AOAC OMA# 2015.10 Methods Review (January 23, 2019)

FOR EXPERT REVIEW PANEL USE ONLY NOT FOR DISTRIBUTION

Expert Review Panel for Infant Formula and Adult Nutrition Evaluation of Method - 2015.10 (Reviewer 1)

Method Title Determination of Free and Total Choline and Carnitine in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (LCMSMS)

Method Author Jeffrey Shippar

Reviewer Name: Reviewer 1

Summary of Method Samples are extracted in water for free carnitine and choline. For total carnitine and choline, samples are digested with nitric acid by microwave. Free and total extracts are both diluted to volume with water, mixed with acetonitrile, and analyzed using liquid chromatography (LC) with tandem mass spectrometric (MS/MS) detection.

Method Scope/Applicability Applicable to the measurement of total and free carnitine and choline by UHPLC MS/ MS in infant formula and adult/pediatric nutritional formula.

General Comments about the method Good and simple method employing internal standard for improved accuracy and precision purpose.

Method Clarity Good, could be easily followed by the collaborators.

Pros/Strengths Nicely validated method in most of the aspects. Method capable of analyzing both choline as well as carnitine and both as free as well as total. • The method uses internal std for both analytes during extraction as well as analysis. • Specific for analytes • The method is relatively faster and simple