Determination of ethyl carbamate in wine by high performance liquid chromatography

Abstract

Kinetics of pre-column derivatization with 9-xanthydrol for the determination of ethyl carbamate (EC) in wine by a previous high performance liquid chromatographic method with fluorescence detection was studied and further developed. The life-time of the derivatized product and its excitation/absorption spectra were systematically investigated. Using low acidity (pH=2.5 set by phosphate buffers) only 3% of 9-xanthyl ethyl carbamate (XEC) decomposes in ∼48h, allowing a prolonged storage time of the derivatized EC conferring more accurate determination for large sample batches. Detection limit of this method is 3μgL(-1), while its average recovery is 98.5±4.9%. Calibration is linear up to 400μgL(-1). The EC content in 33 Hungarian wine samples ranges from 4.9 to 39.9μgL(-1) (average: 17.7μgL(-1), median: 16.7μgL(-1)), while only three of them was slightly over 30μgL(-1) EC, it being the maximum allowed concentration in countries already having legislation.