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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 9
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RESULTS
Part 1. Method set up and qualification of participants
Participation
Twenty six laboratories initially agreed to participate to the MLT. Two
laboratories dropped out during Part 1 due to issues related to availability of
resources.
Method set up
All twenty four laboratories managed to easily set up the method as described in
the protocol. Fourteen laboratories used UPLC conditions as described in the
method, while nine laboratories used HPLC conditions as previously published
(Fontannaz et al., 2006).
During the method set up, it was brought to the attention of the Study Director
the need to establish a suitability test to ensure proper chromatographic
separation between ascorbic acid, isoascorbic acid and orotic acid. This will be
included in the final method.
Practice
samples
results
One of the laboratories did not manage to receive the practice samples due to
Customs restrictions; the laboratory qualified using results from known samples.
After data compilation, average and standard deviation of repeatability and
reproducibility were calculated. Laboratories reporting data above or below
(average ± 2 * S
R
) were flagged as possible outliers and informed about it.
Nevertheless, they were accepted to continue since their results, although
questionable, were still within (± 3 * SD
R
).
Full set of data is shown in Annex G.
AOAC OMB Meeting Book
343