How to Test for Potassium Sorbate
- 1). Add one ml. of acetone to the sample. Dissolve the sample in dilute hydrochloric acid. The potassium sorbate will ionize to form sorbic acid in the chemical solution.
- 2). Dissolve the sample in water. If it is potassium sorbate, it will release sorbic acid.
- 3). Collect the precipitated sorbic acid on a filter paper.
- 4). Wash the filter paper free of chloride with water, and dry it under a vacuum over sulfuric acid.
- 5). Add a few drops of bromine solution. The color of the bromine solution disappears immediately.
- 6). Observe to see if there is potassium salt (cystalline powder that is white or slightly yellow), on the filter paper. Potassium sorbate is the potassium salt of sorbic acid.