370 / 435
Multi Laboratory Test – AOAC First Action Method 2012.22 Ascorbic Acid (Vitamin C) in Infant Formula and
Adult/Pediatric Nutritionals.
RDLS-RD150006
E. Campos Giménez (NRC, Lausanne)
Page 8
CONFIDENTIAL
The contents of this document constitute a trade secret and the intellectual property rights thereto belong to Nestlé S. A., Vevey, Switzerland.
This document may not be reproduced or disclosed to third parties without prior authorisation.
Part 2: Multi-Laboratory Test Participation
MLT Samples
Receipt
All qualified laboratories received a second shipment containing twenty
samples for the MLT. The “SPIFAN MLT Samples Receipt Form” (Annex E)
was to be filled and sent back to the Study Director.
Analysis
The laboratories were asked to analyze all the samples (single extraction
from each reconstituted sample) on two days (10 samples per day). Each
sample was assigned to either day 1 or day 2 (see Annex A).
The samples were analyzed singly and individual values reported. It was of
critical importance to analyze the samples on their assigned day. It was also
highlighted to the participants that this was a study of the method, not the
laboratory; the method set up in the first part of the study should be closely
followed. Any deviation was to be recorded and reported.
All powdered samples were required to be analyzed on a reconstituted basis,
using 25 grams of material and 200 grams of water, as stated in the method,
with the exception of MLT Sample 2 (EKVJ578) and MLT Sample 6
(VJKY373). These two samples were to be reconstituted by dissolving
10 grams of powder in 90 grams of water (see Annex A for reconstitution
rates).
If there were any questions, the laboratories were instructed to directly
address them to the Study Director.
Timeline
The results on the MLT samples were to be provided within 6 weeks from
sample reception.
Reporting
An electronic template was provided for data reporting (see Annex F).
Participating laboratories were asked to report peak areas in the standard
curve, as well as in the sample extracts. Furthermore, detailed information on
the different masses and volumes used during sample preparation as
indicated in the method, as well as raw data (chromatograms of standards
and samples) were requested.
Laboratories were required to report final results in mg ascorbic acid/100 g of
“reconstituted powder” for powder samples or “as is” for liquid products, with
3 significant figures.
AOAC OMB Meeting Book
342