AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 METHOD

FOR ERP USE ONLY DO NOT DISTRIBUTE

solution D(a) . Transfer the solution to a 500-mL volumetric flask and make up to the mark with

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water. Stable for 3 months at 4 °C.

(c) Sodium acetate buffer (100 mM, pH 4.5) .—Into a beaker (>500-mL) containing 450 mL of water,

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pipette 2.9 mL glacial acetic acid. Adjust to pH 4.5 with 2 M NaOH solution D(a) . Transfer the

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solution to a 500-mL volumetric flask and make up to the mark with water. Stable for 3 months at

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4 °C.

(d) N,N’-diacetylchitobiose internal standard solution (600 µg/mL) .—Into a 25-mL volumetric flask

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weigh 15 mg N,N’-diacetylchitobiose and make up to the mark with water. Stable for 1 year at -

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20 °C.

(e) Glucose stock solution (5 mg/mL) .—Into a 25-mL volumetric flask accurately weigh 125 mg

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glucose and make up to the mark with water. Stable for 1 year at -20 °C.

(f) Fructose stock solution (10 mg/mL) .—Into a 25-mL volumetric flask accurately weigh 250 mg

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fructose and make up to the mark with water. Stable for 1 year at -20 °C.

(g) Carrez I solution .—Dissolve 10.6 g potassium hexacyanoferrate(II)trihydrate in 100 mL water and

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store in a brown bottle. Stable for 6 months at room temperature. [NB: Optional reagent].

(h) Carrez II solution .—In a 100-mL volumetric flask, dissolve 22.0 g zinc acetate in 90 mL water and

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add 2.9 mL glacial acetic acid. Make up to the mark with water and homogenize. Stable for 6

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months at room temperature. [NB: Optional reagent].

(i) Sodium azide solution (0.5 %).— Dissolve 1 g sodium azide in 200 mL of water [NB: Optional].

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(j) Sucrase/β-amylase/pullulanase/maltase solution .—Dissolve the content of the bottle containing

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freeze-dried powdered sucrase, β-amylase, pullulanase and maltase C(q) in 22.0 mL sodium

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maleate buffer D(b) . Mix well and divide into aliquots of 2 mL each and store frozen at -20 °C in

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polypropylene tubes until use. Stable for 5 years at -20 °C. NOTE: For the development and

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validation of this method, the pre-prepared enzyme mixture available in the Megazyme kit K-

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