AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 MANUSCRIPT

FOR ERP USE ONLY DO NOT DISTRIBUTE

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For the development and validation of this method, the pre-prepared enzyme mixture

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available in the Megazyme kit K-FRUC, was used. When enzymes from another source are

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used, buffer composition (type, concentration and pH) may need to be adapted to the

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recommendations of the supplier. It is also imperative to ensure the enzyme mixture will

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completely hydrolyse the fructan without hydrolysing any other glucose or fructose

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containing oligo- or polysaccharide that may be present after treatment with the sucrase

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mixture above. This can be checked by performing an analysis with a pure fructan as an

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analyte. More than 90 % recovery should be achieved when a fructan of known purity is

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measured.

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(l) Wash solution for graphitized carbon SPE column (TFA 0.1 % in acetonitrile 80 %

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(v/v)) .—Into a 100-mL volumetric flask, add 80 mL acetonitrile and 100 μL TFA. Make

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up to the mark with water. Stable for 6 months at room temperature.

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(m) Sodium chloride solution (1 M) for graphitized carbon SPE column .—Into a 100-mL

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volumetric flask weigh 5.8 g NaCl and dissolve with 90 mL of water. Make up to the mark

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with water. Stable for 6 months at room temperature.

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(n) Elute solution for graphitized carbon SPE column (TFA 0.05 % in acetonitrile 25 %

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(v/v)) .—Into a 100-mL volumetric flask, add 25 mL of acetonitrile and 50 μL of TFA.

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Make up to the mark with water. Stable for 6 months at room temperature.

E. 19 If using a CarboPac PA1 column (or equivalent), skip this section and go directly to section F . 20 (a) Mobile phase A for CarboPac PA20, sodium hydroxide solution (600 mM).— Into an eluent 21 bottle, introduce 970 mL of water C(a) and degas with helium for 20 min. Add (using a 22 single-use plastic pipette) 31.2 mL of 50 % (w/w) NaOH solution C(j) . Degas with helium 23 for 20 min and protect the eluent from exposure to carbon dioxide until, and during use by 24 suitable means (e.g. by keeping under a blanket of helium). Stable for 1 week at room 25 temperature. 26 Mobile Phase Preparation (Using CarboPac PA20 column or Equivalent)

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