Determination of Selenium in Wines Using Electrothermal Atomic Absorption Spectrometry with Zeeman Background Correction

¹ U.S. Department of the Treasury, Bureau of Alcohol, Tobacco, and Firearms, National Laboratory Center, 1401 Research Boulevard, Rockville, MD 20850.

An electrothermal atomic absorption spectrometry with Zeeman background correction was used for the determination of selenium in table wines. Using palladium (500 µg/L) in 2% hydroxylamine hydrochloride as the matrix modifier, table wines were analyzed for selenium at low parts per billion levels. The detection limit, calculated as 3/slope of the calibration curve, was 9 µg/L in wine. This study points out the importance of reduction of selenium from Se⁶⁺ to Se⁴⁺ for quantitation in wine matrices. A survey of several domestic and imported wines revealed that selenium levels vary with the geographical origins of the grapes and that the levels of Se in wines tested in this study were significantly less than the maximum tolerance level of 50 µg/L in drinking water set by the United States Environmental Protection Agency.

Key words: matrix modifier, background absorbance, charring, asymmetrical peaks, table wines, exogenous factors

Submitted on January 15, 1997