Determination of Methoxyl Content by the ViebOck Schwappach Procedure

3 Determination of Methoxyl Content by the Viebock and Schwappach Procedure (Silbernagel 1980, pers. commun.) 

Bromine, iodine-free, stored in a brown dropping bottle of appropriate volume Carbon dioxide, obtained from a cylinder equipped with pressure regulator and needle valve 

Hydriodic acid, freshly distilled at constant boiling point (127°C) concentration, 57%, density, 1.7 (Note 1) 

Red phosphorus, prepared by digesting 5g of commercial red phosphorus in 50 ml of 5% ammoniacal water on a water bath for 30min. The precipitate is washed with distilled water (Note 2) until the washings are neutral, then with ethanol. Finally, the purified red phosphorus is dried in a forced air oven at 100 °C and stored in a desiccator. 

Sodium acetate solution, 20% in 96% acetic acid by dissolving 20 g of pure sodium acetate in 80 g of 96% acetic acid Sodium acetate, powder 

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