AOAC RI ERP E-Book - DS DF

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

(w) Guard column (or pre-column).— TSK Gel PWx1 guard column (TOSOH). (x) Detector.— Refractive index (RI); maintained at 50°C. (y) Data integrator or computer.— For peak area measurement. (z) Filters for disposable syringe.— 0.45 µm membrane, 13 mm or 25 mm. (aa) Filters for water.— polyvinylidene fluoride, pore size 0.45 µm, 47 mm. (bb) Filter apparatus.— To hold 47 mm, 0.45 µm filter, [B(aa)] ; to filter larger volumes of water. (cc) Syringes.— 10 mL, disposable, plastic. (dd) Syringes.— Hamilton 100 µ L, 710SNR syringe. (ee) Rotary evaporator .—Heidolph Laborota 4000 or equivalent. (ff) Thermometer .—Capable of measuring to 100°C. (a) Ethanol 95 % v/v. or Industrial Methylated Spirits (IMS). Industrial Methylated Spirits made up of: ethanol 84.8333 (w%), 85.952 (v%); water 5.6571 (w%), 4.524 (v%); 2- propanol 4.9118 (w%), 5.0000 (v%); methanol 4.5979 (w%), 4.524 (v%). Can be prepared by mixing 5 volumes of 2 propanol with 95 volumes of denatured ethanol formula SDA- 3A[100 volumes of 95% ethanol combined with 5 volumes of methanol]. (b) Ethanol (or IMS), 78 % .— Place 179 mL water into 1-L volumetric flask. Dilute to volume with 95 % ethanol or IMS. Mix. (c) Acetone , reagent grade. (d) Stock PAA plus AMG powder .— PAA (40 KU/g) plus AMG (17 KU/g) as a freeze-dried powder mixture. Note: One Unit of AMG activity is the amount of enzyme required to release one µ mole of D -glucose from soluble starch per minute at 40°C and pH 4.5; one Unit of PAA activity is the amount of enzyme required to release one µ mole of p -nitrophenyl from Ceralpha reagent per minute at 40°C and pH 6.9; AOAC Method 2002.01). PAA/AMG preparations should be essentially devoid of β -glucanase, β -xylanase and detectable levels of free D -glucose. Stable for > 4 years at −20°C. (e) PAA (4 KU/5 mL)/AMG (1.7 KU/5 mL) .— Immediately before use, dissolve 1 g of PAA/AMG powder in 50 mL of sodium maleate buffer (50 mM, pH 6.0 plus 2 mM CaCl 2 ) and stir for approx. 5 min. Store on ice during use. Use on the day of preparation. AOAC Research Institute ERP Use Only C. Reagents

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

4