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HPLC Determination of Total Tryptophan in Infant Formula and
Adult/Pediatric Nutritional Formula Following Enzymatic
Hydrolysis
Abbott Nutrition, Division of Abbott Laboratories
page
5
1. Accuracy:
a) Average overspike recoveries of Hypoallergenic Infant formula with BSA
and free tryptophan (n=10):
1) NIST BSA: 99.1%
2) Free Tryptophan: 101.3%
a) NIST 1849a assay percent of reference value: 100.4% (mean of n=10)
2. Precision:
a) NIST 1849a (n=30 over 6 months): 2.14%
b) RSD for ten independent runs of duplicate analyses.
3. Second Laboratory Performance with NIST 1849a (n=14)
a) RSD
0.99%
b) Mean value: 0.186 g/100g (101.1% of Reference Value)
J. FIGURES
FIGURE 1
Typical Middle Standard Chromatogram
TRP_SA - 2.395
5MDLT - 6.035
LU
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
11.00
12.00
13.00
14.00
15.00
Minutes
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
5.50
6.00
6.50
7.00
SAMPLE
Within run
Run-to-run
Total RSD
Soy Formula
0.48%
1.64%
1.71%
Hypoallergenic Formula
0.62%
1.68%
1.79%
Amino-02
FOR ERP USE ONLY
DO NOT DISTRIBUTE