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:

9. Preparation of Samples 9.1. Prepare samples using weights and dilutions as shown below. Sample Type mg ml

% Assay Range

1X Liquids

6000 1000 200 200

10 10 10 50 50

0.03 – 0.17

5X, 10X Liquids 20X, 40X Liquids 100X / 200X Powders Purified Aloe (>20 %)

0.2 - 1 1 - 5 5 - 25

50

20 - 100

9.2. Transfer 1.0 ml of sample to a vial and add 2.0 ml alkaline hydroxylamine and mix. Allow the solution to sit at room temperature for 4 minutes. This should be done in duplicate. 9.3. Add the amount of HCl as determined in 7 . 9.4. 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. 10. Analysis 10.1. Zero the spectrophotometer with at 540 nm with the 0 ml standard. 10.2. Measure the absorbance of the other standards and generate a calibration curve. An example curve is show below. The regression coefficient must be ≥ 0.98. c 10.3. Measure the sample and determine the mg/ml using the linear regression equation. 10.4. Calculate the concentration of aloe PS using the following equation: % = 100