AOAC SPIFAN Nutrients ERP-Final Review (Jan. 2019)

2017.03 (JULY 2018) Amino-02 Tryptophan by enz hyd_Abbott Labs_Method

FOR ERP USE ONLY DO NOT DISTRIBUTE

HPLC Determination of Total Tryptophan in Infant Formula and Adult/Pediatric Nutritional Formula Following Enzymatic Hydrolysis

Jonathan Draher and Norman White Abbott Nutrition, Division of Abbott Laboratories

For Blank:

Blank mg = 0.1154 – (-0.004522) × 0.0403 L 0.007082

Tryptophan in Blank = 0.6824 mg/L

Tryptophan Value in g/100g of sample:

TRP (g/100 g sample) = (CTS-CTB) × (Volume/Sample Weight (g)) ×

100/1000

Where:

CTS = Concentration of Tryptophan in Sample CTB = Concentration of Tryptophan in Blank Volume = Final volume in Liters i.e. 50 mL = 0.05L

Sample Computation for RTF Sample: TRP (g/100g Sample) = (6.125 mg/L – 0.6824 mg/L) × (0.05L / 1.0095g) × 100/1000

Tryptophan in g/100g of sample = 0.0270 g/100g sample

Conversion to Protein Basis:

= TRP g 100 100 g protein 100 g Sample % Protein ×

TRP g

Page

16