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Screening Team Review: Consists of a preliminary review by Working Group Chair, ERP Chair, and CSO
ERP Reviews Comments
Am‐01 – 3/2015
Am‐02 – 9/2015
Am‐03 – 2/2016
Method is well written;
sound methodology
Study author should use all
AOAC SPIFAN samples and
provided the information
Analytical range; LOQ
Lysteine has limited range
Title change – total amino
acid
Does not capture tryptophan
Proprietary technique
Recovery over 110%
Method has potential;
needs optimization
The amino acid profile only measures tryptophan
For chosen samples the method showed good precision and accuracy.
Data for NIST SRM 1849a is presented for 2 laboratories and accuracy for this matrix
meets SMPR.
The sample prep takes less time
Sample size is too small/precision
No SPIFAN matrices were used for validation. Limited data for 3 matrices are presented
– NIST SRM 1849a, soy formula and Hypoallergenic formula.
o
Method needs more data on SPIFAN materials
Method uses 3‐point calibration instead of recommended 6‐point and no information
on the range is given.
Actual levels of Tryptophan in studied matrices (except for NIST SRM 1849a) and spike
levels used for accuracy studies are not listed.
Background Tryptophan from self‐digest of enzymes in the absence of the sample is a
concern since this can affect accuracy of analysis at low levels.
One weakness is the limit of quantitation range
Provide additional information on the following:
o
Analytical range
o
wide calibration range
o
system suitability
Method is three (3) methods in one (1); uses three (3) separate
digestions
It is hard to determine how many samples were completed and
in how many days
The intermediate precision was completed over two (2) days
and six (6) replicates daily; the information should be presented
clearer.
Method is promising, but lacks SLV data
One weakness is optimizing the method
Internal standards should be brought in earlier; internal
standard is added after hydrolysis
o
No tryptophan in the internal standards; should investigate
and correct
Full SPIFAN SLV study should be completed
Follow instructions in the use of the AOAC SPIFAN samples
Suitability step should be built in the method to check the
column for separation suitability
WG launched
March 2014
SMPR Approved
Sept 2014
Call for Methods
Sept 2014
April 2015
Oct 2015
Methods Submitted
1/2015 ‐ Am01
8/2015 ‐ Am02
2/2016 ‐ Am03
Screening Team Review
6/2015
12/2015
2/2016
ERP Review
3/2015 ‐ No OMA
9/2015 ‐ No OMA
2/2016 ‐ No OMA
What is Next ?
AMINO ACID METHODS
AOAC OMB Meeting Book
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