AOAC OMB Final Action Recommendation (December 2019)-2016.14

FOS-03 FOR WORKING GROUP/ERP USE ONLY DO NOT DISTRIBUTE

(q) Acetic acid, glacial 100% anhydrous, GR for analysis

(r) Trifluoroacetic acid

(s) D-(-)-Fructose, Biochemika, >99%

(t) Acetonitrile

(u) Sodium maleate buffer solution (100 mM, pH 6.5) - Into a large beaker (>1000 mL)

weigh 11.6 g of maleic acid (puriss., >99%) and dissolve with 900 mL of water. Adjust

the pH to 6.5 with 1 M sodium hydroxide solution (p). Transfer the solution to a

1000 mL volumetric flask and make up to the mark with water.

(v) Sodium acetate buffer solution (100 mM, pH 4.5) - Into a large beaker (>1000 mL)

containing 900 mL of water, pipette 5.8 mL of glacial acetic acid (q). Adjust to pH 4.5

with 1 M sodium hydroxide solution (p). Transfer the solution to a 1000 mL

volumetric flask and make up to the mark with water.

(w) Sodium hydroxide solution (50 mM) - Into a 100 mL volumetric flask, weigh 0.2 g of

sodium hydroxide pellets and dissolve with 90 mL of water. Make up to the mark

with water.

(x) Sodium borohydride (10 mg/mL in 50 mM sodium hydroxide) – accurately weigh 50

mg of sodium borohydride in to a polypropylene tube and record the weight.

Immediately before use dissolve in an appropriate volume of 50 mM sodium

hydroxide solution (w) to give a final concentration of 10 mg/mL.

(y) Acetic Acid (0.2 M) – Into a 1000 mL volumetric flask containing 900 mL of water,

pipette 11.6 mL of glacial acetic acid (q). Make up to the mark with water.

(z) Fructan Assay Kit, K-FRUC (Megazyme International Ireland Ltd, Wicklow, Ireland).

(aa) Sucrase (~4.5 U/mL) / α-amylase (~23 U/mL) / pullulanase (~4.5 U/mL) / maltase

(~45 U/mL) solution; dissolve the contents of the sucrase / amylase /pullulanase /

maltase vial from the fructan assay kit (z) in sodium maleate buffer (m) following the

instructions from the kit. Divide into aliquots of 2.0 mL (enough for 9 sample

determinations) and store frozen at -20°C in polypropylene tubes until required.

(bb)

Fructanase solution (exo-inulinase ~ 455 U/mL + endo-inulinase ~4.5 U/mL);

dissolve the contents of the fructanase vial from fructan assay kit (z) in sodium

acetate solution (v) following the instructions from the kit . Divide into aliquots of

2.0 mL (enough for 18 sample determinations) and store frozen at -20°C in

polypropylene tubes until required.

(cc) SPE wash solution - Into a 100 mL flask, add 80 mL of acetonitrile and 100 µL of TFA.

Make up to the mark with water.