AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 MANUSCRIPT

FOR ERP USE ONLY DO NOT DISTRIBUTE

(j) Sodium hydroxide .—50 % ( w/w ). Carbonate is a divalent anion at pH ≥ 12 and binds 1 strongly to the analytical column. It causes decrease of column selectivity and reduction 2 of resolution and efficiency. To keep the concentrated NaOH solution carbonate free and 3 avoid production of carbonate, several precautions should be taken: 4 - The bottle should be handled with care to keep the precipitated carbonate at the bottom 5 (do not shake or stir before use). 6 - The solution should never be poured from the bottle. 7 - Only plastic pipettes should be used. 8 - The solution should be pipetted from the center of the bottle, not from edges or bottom. 9 - The unused solution should never be returned to the bottle. 10 - The bottle should be closed immediately after each use. 11 - Only the 2/3 of the NaOH solution in the original bottle should be used for preparing 12 eluents. Remaining solution can be used for other applications, including preparation 13 of the solution for post-column addition. 14 (k) Sodium hydroxide .—Pellets for analysis. 15 (l) Sodium chloride .—For analysis, ACS,ISO,Reag. Ph Eur. 16 (m) Sodium azide.— [Optional]. 17 (n) D-(-)Fructose .—≥99.0 %. 18 (o) D-(+)-Glucose. —≥99.5 %. 19 (p) N,N’-diacetylchitobiose .—>90 %. 20 (q) Mixture of highly purified sucrase, β -amylase, pullulanase and maltase .—200 µL of 21 enzyme mixture working solution D(j) should be able to completely hydrolyse 2 mg of 22 sucrose under the conditions described in the method (90 min at 40 °C) without 23 hydrolysing any fructans (Fructan Assay Kit, K-FRUC, Megazyme International Ireland 24 Ltd, or equivalent). 25

10