SPDS Aloe Vera Method Book

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Standard Operating Procedures

Subject: Aloe Polysaccharides by O-Acetyl Department: Laboratory Original Date: 06/20/2016 Revision #: 1

Procedures #: CA17011

Approval Date:

6. Preparation of Alkaline Hydroxylamine (prepare on day of use) Mix equal volumes of hydroxylamine hydrochloride and sodium hydroxide. 7. Optimization of pH 7.1. The optimum pH for color development needs to be in the range of 1.0 – 1.4. 7.2. Mix 1.0 ml of DI water, 2.0 ml of alkaline hydroxylamine, 0.7 ml 4 M HCl and 1.0 ml of ferric chloride. 7.3. The pH of this solution should be 1.0 – 1.4. Modify the amount of HCl until the pH is in this range. If the pH is not acidic enough (> pH 3) a brown precipitate will form. 8. Preparation of Calibration Standards (0.2 – 1.0 mg/ml), (prepare on day of use) 8.1. Weigh 50 mg (to the nearest 0.01 mg) of acetylcholine chloride to a 50 ml volumetric flask and dilute to volume with sodium acetate solution. ml Acetylcholine ml Water 0.0 1.0 0.2 0.8 0.4 0.6 0.6 0.4 0.8 0.2 1.0 1.0 8.2. Add 2.0 ml alkaline hydroxylamine and mix. Allow the solutions to sit at room temperature for 4 minutes. 8.3. Add the amount of HCl as determined in 7 . 8.4. Add 1.0 ml of ferric chloride. Gas bubbles will form in the solution which are easily removed by a few minutes in an ultrasonic bath. 8.5. If the pH of the solution is within the 1.0 – 1.4 range, the blank sample will be yellow and the standards and samples will be a reddish orange color.