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FOR EXPERT REVIEW PANEL USE ONLY
NOT FOR DISTRIBUTION
1
Expert Review Panel for Infant Formula and Adult Nutrition
Evaluation of Method Chol-08/Carn-07
Title: Determination of Free and Total Choline and Carnitine in Infant Formula and Adult/Pediatric
Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
Author:
David Ellingston, Covance
Summary of Method:
An analytical method for the analysis of free as well as total carnitine and choline in infant formula
and adult/pediatric nutritional formula was developed with a simultaneously analysis of both the
analytes using strong cation exchange (SCX) chromatography
.
The free portion is analyzed using
water extraction, while the total extraction employs acid assisted microwave hydrolysis. The
total amount can include contribution from bound sources such as phosphatidylcholine or acetylcarnitine.
Both extraction methods employ LCMSMS analysis with electrospray
ionization (ESI). Calibration standards are included through each extraction procedure.
Method Scope/Applicability:
The analysis of free as well as total carnitine and choline in infant formula
and adult/pediatric nutritional formula
General comments about the method:
It’s an easy method to specifically analyze total as well as free choline and carnitine in the samples. The
extract ion of analytes present in free form is a simple water extraction. The extraction of the analytes in
the bound form is a relatively faster (about 1 hr) using microwave hydrolysis. The analysis is MS/MS based
and thus specific. The method employs labeled choline and carnitine as internal stds.
Method Clarity:
Good. The authors may provide a Table providing concentrations of analytes in each level of working
standard including internal std.
#2
Chol-08 Review Forms