Survey of benzene in foods by using headspace concentration techniques and capillary gas chromatography

Recently, the combination of sodium or potassium benzoate with ascorbic acid was shown to produce low levels (ng/g) of benzene in fruit-flavored soft drinks. The presence of benzene also was reported in butter, eggs, meat, and certain fruits; levels of these findings ranged from 0.5 ng/g in butter to 500-1900 ng/g in eggs. Because benzoates are widely used as food preservatives, a limited survey of other foods containing added benzoate salts was conducted to investigate the potential for benzene formation. Selected foods that did not contain added benzoates but were previously reported to contain benzene were analyzed for comparison. More than 50 foods were analyzed by purge-and-trap or static headspace concentration and capillary gas chromatography. Benzene was quantitated by using the method of standard additions, and its identity was confirmed by mass selective detection. Results of this limited survey show that foods without added benzoates (including eggs) contained benzene at levels equal to or less than 2 ng/g. Slightly higher levels were present in some foods and beverages containing both ascorbic acid and sodium benzoate.