AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 MANUSCRIPT

FOR ERP USE ONLY DO NOT DISTRIBUTE

Table 2016.14B. Dilution scheme for the preparation of the standard curve 1

Volume of fructose stock solution, µL

Volume of glucose stock solution, µL

Fructose concentration, µg/mL

Glucose concentration, µg/mL

Final volume, mL

Standard

Level 1 Level 2 Level 3 Level 4 Level 5 Level 6

200 400 800

40

100

20

2

200 400 600 800

20 20 20 20 20

200 400 600 800

50

100 150 200 250

1200 1600 2000

1000

1000

2

H. 3 (a) Products on a ready-to-feed basis (RTF) and powder products inhomogeneous at the 4 subgram level .—Reconstitute powder or liquid concentrates according to instructions. For 5 example, accurately weigh 25 g ( m R ) of infant formula powder into an appropriate bottle, 6 add 200 g water ( V R ) and mix well at room temperature to form a homogeneous suspension. 7 Proceed as described in H(b) . 8 (b) Reconstituted products (as prepared above), or products sold as RTF .—Mix well to ensure 9 homogeneity of the test portion. Weigh 9 g ( m A ) of sample into a 50-mL volumetric flask 10 ( V A ). Add 30 mL water and confirm the pH is between 5 - 9 (adapt if needed, using 11 hydrochloric acid or sodium hydroxide). Heat at 80 °C with constant agitation for 20 min. 12 Cool to room temperature and make up to the mark with water (this is “Solution A”). 13 Proceed as described in H(d) . 14 (c) Homogeneous powder products without prior reconstitution .—Weigh 1 g ( m A ) of powder 15 into a 50-mL volumetric flask ( V A ). Add 30 mL water and confirm the pH is between 5 – 9 16 (adapt if needed, using hydrochloric acid or sodium hydroxide). Heat at 80 °C with 17 constant agitation for 20 min. Cool to room temperature and complete to the mark with 18 water (this is “Solution A”). Proceed as described in H(d) . 19 Sample Preparation

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