AOAC RI ERP E-Book - DS DF

OMAMAN-38 A: Collaborative Study Manuscript Expert Review Panel Use Only September, 2017

(k) MES buffer.— {this can be used as an alternative to sodium maleate buffer; [c(j)] }. 50 mM, pH 6.0 plus 2 mM CaCl 2 .– Dissolve 19.5 g of MES [2-( N -morpholino) ethanesulfonic acid] (Megazyme cat. no. B-MES250) in 1600 mL of deionised water and adjust the pH to 6.0 with 4 M (160 g/l) NaOH solution. Add 0.6 g of calcium chloride (CaCl 2 .2H 2 O) and adjust the volume to 2 L. Solution is stable for ~ 2 weeks at 4°C. ( Alternatively , prepare the buffer with the addition of sodium azide. In this case, add 0.4 g of sodium azide to 2 L of final buffer solution and dissolve with stirring. Stable for > 2 years at 4°C). (l) Trizma Base (Megazyme cat. no. B-TRIS500), 0.75 M.— Add 90.8 g of Trizma base to approx. 800 mL of distilled water and dissolve. Adjust volume to 1 L. Stable for > 1 year at room temperature . (m)Acetic acid solution, 2 M.— Add 115 mL of glacial acetic acid (Fluka 45731) to a 1-L volumetric flask. Dilute to 1-L with distilled water. Stable for > 1 year at room temperature. (n) Sodium azide solution (0.02 % w/v). — Add 0.2 g of sodium azide to 1 L of deionized water and dissolve by stirring. Stable at room temperature for > 1 year. (o) Cleaning solution.— Micro (International Products Corp., Trenton, NJ). Make a 2 % solution with deionized water. (p) pH standards.— Buffer solutions at pH 4.0, 7.0 and 10.0. (q) Deionized water . (r) Celite.— acid-washed, pre-ashed (Megazyme G-CEL100 or G-CEL500). (s) Amberlite ® FPA53 (OH − ) resin (Megazyme cat. no. G-AMBOH), ion exchange capacity 1.6 meq/mL (minimum) and Ambersep ® 200 (H + ) resin (Megazyme cat. no. G-AMBH), ion exchange capacity: 1.6 meq/mL (minimum).

Items (d), (f), (g), (h) and (i) are supplied in the Rapid Integrated Total Dietary Fiber kit available from Megazyme, Bray Business Park, Southern Cross Road, Bray, County Wicklow, Ireland, but preparations of reagents and buffers which meet the criteria as specified in the method above may also be used. AOAC Research Institute ERP Use Only

Method updated 2008--08-10 This copy printed 22 August 2017

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