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Introduction
Thank you for accepting the invitation to participate in the AOAC collaborative study for the
validation of the method for the determination of i13-Cis and all-trans Vitamin A Palmitate
(retinyl palmitate), Vitamin A Acetate (retinyl acetate), and Total Vitamin E (α-Tocopherol and
DL-α-Tocopherol Acetate) in Infant Formula and Adult Nutritionals by Normal Phase HPLC.
It
is important to remember that this is a test of the methodology involved and not a test
of the individual laboratories or their personnel. In this regard, it is very important to
follow these directions and the enclosed method exactly.
If for any reason you are not
able to complete the study, please contact the Study Director as soon as possible.
Overview
Your participation in this study will consist of three parts.
a) The first will be instrument setup, check procedure and preparation of reagents and
calibration standards. Before running any samples run the System Suitability checks as
outlined in the method to ensure that the system is working as specified. The results of
the System Suitability checks must be included in the results sent to the study director.
b) The second phase will be the analysis of practice samples. For laboratories that are
unfamiliar with the method, practice samples such as reference materials will be analysed
in order to become familiar with the complete analysis procedure. This will ensure that
instrumentation is working properly and reagents/solutions/calibration standards are all
prepared correctly in advance of conducting the actual study. These results will be
submitted to the study director for approval prior to commencing the MLT. Results within
a range of expected levels will indicated that the laboratory has the capability to run the
analysis successfully.
c) The third phase will consist of the analysis of the actual test materials following the go
ahead from the study director. After the determinations are complete, the results will be
returned to the Study Director for review.
The results from all collaborators will be compiled by the Study Director and sent to the AOAC
Statistician for detailed analysis. Upon approval by the statistician, the study report will be
written and submitted to the AOAC Methods Committee for review and approval as an
Official
First Action
AOAC Method, and subsequent publication in the Journal of AOAC
INTERNATIONAL.
A more detailed description of the work required in the form of a flow diagram is presented in
Figure 1.
Vitamin A & E MLT Protocol
For ERP Use Only
DO NOT DISTRIBUTE
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