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Abstract
A multi-laboratory study was conducted to determine the vitamin D
2
and D
3
content in
infant formulas and adult/pediatric nutritional formulas. Ten laboratories participated in
the analysis of blind duplicates of 12 samples of infant formula and adult nutritional
products.
Test samples were saponified overnight and then extracted by liquid-liquid extraction
with an organic solvent. The organic layer was washed and a portion of this layer was
then evaporated to dryness using nitrogen gas. Residues were reconstituted with organic
solvent and analyzed using ultra high performance liquid chromatography with tandem
mass spectrometric detection (UHPLC-MS/MS). Stable isotope internal standards were
used in the quantitation of both vitamin D
2
and D
3
. Data was collected from ten
laboratories and is presented in Table1.1 and Table 1.2. The HorRat values for all results
were excellent, ranging from 0.27 – 0.52. The RSD
r
ranged from 2.55 – 13.5% and the
RSD
R
ranged from 8.89 – 16.2%. Of the twelve samples, results from eight of the
samples met all of the AOAC 2011.004 SMPR guidelines, while four samples fell
slightly out of range.
Result Summary
The results demonstrate that the method is fit-for-purpose to determine vitamin D
2
and
D
3
in infant formula and adult/pediatric nutritional formula and the Study Director
recommends that it be adopted Final Action
Official Method
status.
Introduction
The AOAC INTERNATIONAL
Official Method
2011.11 entitled, “Vitamin D in Infant
Formula and Adult/Pediatric Nutritional Formula,” was selected by the AOAC Expert
Review Panel (ERP) as a First Action method for the determination of vitamins D
2
and
D
3
. The single laboratory validation (SLV) and the multi-laboratory testing (MLT) of
this method have been completed.
Collaborative Study
Purpose
The purpose of this study was to evaluate the method’s intra-laboratory and inter-
laboratory performance and submit the results to the AOAC INTERNATIONAL for
adoption as a Final Action
Official Method
for the determination of vitamins D
2
and D
3
in infant formula and adult/pediatric nutritional formula.
Study Design
This study was conducted on twelve fortified test materials, one of which was NIST SRM
1849a Infant/Adult Nutritional Formula. Random identification numbers were assigned
to each of the twelve fortified test materials including milk and soy based infant formulas
and adult nutritional powders.
2011.11 VITAMIN D MLT-Sept 2015
FOR ERP USE ONLY
DO NOT DISTRIBUTE