Acid methanolysis and gas chromatographic determination of brominated vegetable oils in soft drinks

A gas chromatographic method has been developed for determination of brominated vegetable oils in citrus-flavored soft drinks. Oils were extracted from the drinks with ethyl ether and subjected to acid-catalyzed methanolysis. The resulting brominated methyl esters (dibromostearate, tetrabromostearate, and hexabromostearate) were separated and quantitated as single peaks on a 3% OV-3 column. Chromatography columns were stable for about 3 months of daily use; then the first 15 cm of column packing material was replaced or a new column was prepared. A number of citrus soft drinks were analyzed and contained 3.5-3.9 mg brominated oil/10 fl. oz. Recoveries from spiked samples after organic extraction and methanolysis were 94.5-105%.