Microanalysis of Brominated Oil in Soft Drinks

Abstract

The analysis of brominated oil in soft drinks was studied. Brominated oil was extracted with hexane, the extract was concentrated to about 1ml and decomposed by oxygen flask combustion method, bromine liberated was absorbed into 10ml of 0.1N sodium hydroxide solution. After the solution was neutralized with 1N acetic acid, 3ml of the solution was placed in a small porcelain dish, 1ml of 0.01% fluorescein in 0.1N sodium hydroxide solution and 1ml of 5% peracetic acid solution prepared with acetic acid and 30% hydrogen peroxide were added, and evaporated to dryness on a water bath, the red color appeared on the residue which was due to eosin produced from bromine and fluorescein. The limit of detection was 4μg of bromine in 3ml of the neutralized solution.Sodium chloride and potassium iodide were tested by the presented method, and chloride was not colored, on the other hand a red color appeared with iodide, however, it seemed that the analysis was not interfered with iodide, because iodides were not contai ned in soft drinks and the reagents used for the tests.Bromine in the prepared solution was determined as follows. One milliliter of the prepared solution was heated in a water bath for two hours after mixed with 1ml of fluorescein solution and 1ml of 5% peracetic acid solution. After cooling, 2ml of 10% ammonia water was added to the mixture and filled up to 20ml with water, the absorbance of the solution was measured at 517mμ of wavelength. The recovery of brominated oil in soft drinks was 94-95%.