Bromine (Br) Determination by Schoniger Combustion (Oxygen Flask Combustion Method) (CAT#: STEM-EA-0002-ZJF)

The Schoniger combustion (also known as the oxygen flask combustion method) is a method of elemental analysis first developed by Wolfgang Schoniger in 1955.
The test is conducted in an Erlenmeyer flask or a separatory funnel. A sample is burned in pure oxygen, and then the combustion products are absorbed by sodium hydroxide solution. According to its definition, the oxygen flask combustion method is useful for identifying or determining whether sulphur or halogens are produced when organic compounds are burned. Compounds like these contain iodine, fluorine, bromine, chlorine, or sulphur in a flask containing oxygen. Combustion of these compounds produces inorganic products that are soluble in water. As a result of this process, the inorganic materials produced are determined to be bound for each element. Extreme care should be taken when performing the test. Any organic solvent must be completely removed from the flask before use.

Water purification, agriculture, fuels, healthcare, photography, brominated flame retardants (BERs), etc.

1. Solid samples are weighed into ashless paper and inserted into platinum stoppers.
2. A separatory funnel containing the appropriate reagents is fitted to the stopper.
3. Washing with i-ProH removes the resulting liquid.
4. As an indicator, 2,7'-Dichlorofluorescein is used to titrate the liquid.

• Oxygen flask combustion apparatus
• Sample material

1. Para-bromobenzoic acid (39.75% Br) is used as a calibration standard for bromine determinations. It should be noted that higher levels of Bromine require a smaller sample, whereas lower levels of (expected) Bromine require a larger sample.
2. The interferences here include chlorine and iodine. Providing there is a clear ratio between Br and Cl in the sample, Br & Cl can be tested together in the same sample. This ratio must be given to us in the form of a molecular formula. In the presence of a small amount of Cl impurity, Br cannot be analyzed.