AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 METHOD

FOR ERP USE ONLY DO NOT DISTRIBUTE

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L.

Calibration & Calculations

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Use bracketed calibration by injecting 3 standards followed by 10 samples, and repeating this process 301

(e.g., inject standards at levels 1, 3 and 5 then 10 samples; inject standards at levels 2, 4 and 6 then 10 302

samples; inject standards 1, 3, 5, etc.). For each analyte (glucose and fructose) use the instrument 303

software to plot a six-point standard curve of [Instrument response (area) for analyte] / [Instrument 304

response (area) for internal standard] against the concentration of the analyte in the standard. Fit a 305

quadratic curve to the data without forcing through zero. Use the calibration curve to calculate the glucose 306

and fructose concentrations in Solution B. For the blank measurements, ignore any signals if they are not 307

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greater than 10x the signal-to-noise ratio.

(a) Calculate the glucose released from fructans, C G

, in g/100 g RTF or reconstituted product (sample

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preparation according to H(b) ) or powder product (sample preparation according to H(c)), as

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follows:

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= × × � � × 0.0001

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(b) Calculate the fructose released from fructans, C F

, in g/100 g RTF or reconstituted product (sample

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preparation according to H(b) ) or powder product (sample preparation according to H(c)), as

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follows:

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= × × � � × 0.0001

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(c) Calculate the total fructan content, TF , in g/100 g RTF or reconstituted product (sample

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preparation according to H(b) ) or powder product (sample preparation according to H(c)), as

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follows:

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