2016 OMB Summer Meeting

AOAC OMB Meeting Book

35

AMINO ACID METHODS 

Methods Submitted 1/2015 ‐ Am01 8/2015 ‐ Am02 2/2016 ‐ Am03

Call for Methods Sept 2014 April 2015 Oct  2015

Screening Team Review 6/2015 12/2015 2/2016

ERP Review 3/2015 ‐ No OMA 9/2015 ‐ No OMA 2/2016 ‐ No OMA

WG launched March 2014

SMPR Approved Sept 2014

What is Next ?

Screening Team Review: Consists of a preliminary review by Working Group Chair, ERP Chair, and CSO  

ERP Reviews Comments 

Am‐01 – 3/2015   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 

Am‐02 – 9/2015 

Am‐03 – 2/2016 

 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 

 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.  

 Proprietary technique   Recovery over 110%   Method has potential;  needs optimization 

 One weakness is the limit of quantitation range    Provide additional information on the following:  o Analytical range  o wide calibration range  o system suitability